Journals >Opto-Electronic Engineering
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2017
Volume: 44 Issue 12
47 Article(s)
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Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1131 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1132 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1132 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1132 (2017)
Research and development of femtosecond-laser hyperdoped silicon
Zixi Jia, Song Huang, Xiaorong Jin, Ming Yang, Zhandong Chen, Jianghong Yao, Qiang Wu, and Jingjun Xu
Femtosecond laser pulses induce intriguing transient photochemical reactions with semiconductors at the sample surface, due to its ultrashort duration and ultrahigh peak power. Taking advantage of these character-istics, material can be effectively doped. The doping level is likely far beyond the solid solubility limitFemtosecond laser pulses induce intriguing transient photochemical reactions with semiconductors at the sample surface, due to its ultrashort duration and ultrahigh peak power. Taking advantage of these character-istics, material can be effectively doped. The doping level is likely far beyond the solid solubility limit (so called supersaturated doping), meanwhile quasi-periodic structures with micro/nano- scales are created at the material surface as well. As a result, surface properties are strikingly changed, e.g. ultra-high absorption over a broad range from near ultraviolet to infrared emerges, which breaks the limit of traditional physics and brings novel ap-plications. In this review, we summarize the basic theories and several physical models of femtosecond la-ser-silicon interaction, introduce its applications in relevant areas, and depict future prospects of femtosecond laser hyperdoped and processed silicon..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1146 (2017)
Research progress in superhydrophobic surfaces fabricated by laser
Huan Yang, Yu Cao, Fengping Li, and Wei Xue
Over the past few decades, many methods have been developed to fabricate superhydrophobic sur-faces because these surfaces are useful in several important applications such as anti-corrosion, oil-water sep-aration, friction reduction, and liquid transportation. Surface morphology is a key factor to determine the wettabOver the past few decades, many methods have been developed to fabricate superhydrophobic sur-faces because these surfaces are useful in several important applications such as anti-corrosion, oil-water sep-aration, friction reduction, and liquid transportation. Surface morphology is a key factor to determine the wettabil-ity of a solid surface, and patterning is one of the effective ways to change the surface morphology and to im-prove the wetting properties. Laser patterning using a pulse laser source is a unique technique that can modify the surface morphology with very limited distortion of the bulk material. Moreover, it is a noncontact method, and complex patterns can be created. In this paper, we summarized several typical approaches, theories and relevant applications of laser fabricated superhydrophobic surfaces..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1160 (2017)
Review of UV laser and its applications in micromachining
Shilin Nie, and Yingchun Guan
Ultraviolet (UV) laser has unique advantages in micromachining due to short wavelength, high ma-chining accuracy and cold processing property, leading to improve manufacturing quality effectively. In recent years, electronic industry has been developed rapidly and needs high fabrication requirements. Progress of UV lasUltraviolet (UV) laser has unique advantages in micromachining due to short wavelength, high ma-chining accuracy and cold processing property, leading to improve manufacturing quality effectively. In recent years, electronic industry has been developed rapidly and needs high fabrication requirements. Progress of UV laser has attracted much attention in applications of electronic industry because it can produce complex struc-tures on almost any materials with flexible process and small heat-affected zone. In this review, we summarize the history of UV laser development and fundamental principles as well as characteristics of excimer laser and diode pumped solid state laser, which are two major UV lasers used for micromachining. Moreover, we analyze the development and applications of UV laser in micromachining of semiconductor, optical element and polymer. Finally, we propose some prospects for further research and development in UV laser and its applications..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1169 (2017)
Fabrication and bacterial adhesion of metal dry electrode with surface microstructure arrays
Shaoyu Liu, Wei Zhou, Yaoyao Li, Jiachang Fang, Chenying Zhang, Ronghua Lu, and Guifeng Ye
To develop a high performance biomedical dry electrode, the laser micromilling-recasting technology is used to fabricate the metal dry electrode with surface micostructure arrays. Based on the analysis of the micro morphology of the electrode surface, the wettability of the electrode surface is discussed, and then the To develop a high performance biomedical dry electrode, the laser micromilling-recasting technology is used to fabricate the metal dry electrode with surface micostructure arrays. Based on the analysis of the micro morphology of the electrode surface, the wettability of the electrode surface is discussed, and then the influence of laser processing parameters such as scanning spacing, scanning speed and scan times on the adhesion per-formance of Escherichia coli is further investigated. The results show that the contact angle of metal dry electrode with surface microstructure arrays fabricated with reasonable laser processing parameter can reach more than 150° and show the superhydrophobic characteristics. The adhesion performance of escherichia coli of electrode is changed greatly with different scanning spacing and scan times. When the 0.1 mm scanning spacing is se-lected, the least amount of escherichia coli is found on the surface of electrode. With the increasing scan times, the adhesion amount of escherichia coli can be reduced. However, the scanned speed has little effect on the adhesion performance of escherichia coli for metal dry electrode..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1187 (2017)
Effect of constant temperature substrate on microstructure and hardness of Al2O3-based eutectic ceramics
Hanchao Liu, Fan Lu, Guangyi Ma, and Dongjiang Wu
Al2O3-YAG eutectic ceramic has become an ideal alternative to high-temperature alloys because of its excellent high temperature strength, high oxidation resistance and high temperature structural stability. The technology of laser engineered net shaping was used to prepare the Al2O3-YAG eutectic ceramic thin-wall sam-pAl2O3-YAG eutectic ceramic has become an ideal alternative to high-temperature alloys because of its excellent high temperature strength, high oxidation resistance and high temperature structural stability. The technology of laser engineered net shaping was used to prepare the Al2O3-YAG eutectic ceramic thin-wall sam-ples. These samples were prepared on a common substrate and a water-cooled constant temperature substrate respectively. Their microstructure and microhardness were compared. The results show that the microstructure of thin-wall sample prepared on the common substrate is three-dimensional network structure with an average eu-tectic spacing of 0.96 μm. And the microstructure of top part of the sample prepared on the water-cooled constant temperature substrate is colony structure, while the microstructure of bottom part is dendrite structure which grows in the reverse direction of the heat flow. The average eutectic spacing of samples prepared on the wa-ter-cooled substrate has reduced to 0.21 μm. Compared with the microhardness of two kinds of thin-wall sam-ples prepared on the different substrates, it is found that the microhardness of the thin–wall samples prepared on the water-cooled constant temperature substrate is increased by about 10%..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1194 (2017)
Picosecond laser microfabrication of infrared antireflective functional surface on As2Se3glass
Qiang Yang, Lingfei Ji, Bo Xu, Tianyang Yan, Wenhao Wang, and Zhenyuan Lin
Large-scale periodic dot matrix anti-reflective microstructures were fabricated on the surface by using UV picosecond laser with rapid line scanning to improve the infrared transmittance of As2Se3glass. In the study, the laser ablation threshold of As2Se3glass was concluded and the optimal line scanning method was desiLarge-scale periodic dot matrix anti-reflective microstructures were fabricated on the surface by using UV picosecond laser with rapid line scanning to improve the infrared transmittance of As2Se3glass. In the study, the laser ablation threshold of As2Se3glass was concluded and the optimal line scanning method was designed. The transmittance of the fabricated chalcogenide glass increased about 10.0 % and 5.2% in wavelength ranged from 11.0 μm~12.4 μm and 13.0 μm~14.2 μm, respectively. In addition, the wettability of the glass was not dam-aged by laser scanning. The processing was carried out in air condition showing low cost, high controllability and high efficiency. It only took 3.65 s to finish the fabrication of 8 mm×8 mm surface structures. Both the size and space of the surface microstructure unit can be controlled according to the application requirement. The removal of the chalcogenide glass induced by laser was mainly based on "cold fabrication" in which no obvious thermal effects inducing the element change on the surface were observed. Higher laser energy could induce obvious thermal effect resulting in melting of the ablation points and bump of the crater edges..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1200 (2017)
Mechanism of laser derusting and surface properties of low carbon steel
Zhiguo Ren, Changzhong Wu, Huaining Chen, Ying Lu3*, Hongchao Qiao, and Taiyou Hu
Laser derusting technology is a new and green rust removing method. For some low carbon steel in an environment prone to rust, traditional rust removing method can be replaced by laser derusting technology, which has broad prospects. The corrosion surface of the laser radiation has the characteristics of high laser eneLaser derusting technology is a new and green rust removing method. For some low carbon steel in an environment prone to rust, traditional rust removing method can be replaced by laser derusting technology, which has broad prospects. The corrosion surface of the laser radiation has the characteristics of high laser energy and short pulse, so that the corrosion temperature quickly reaches above the melting point. But at the same time of laser rust removal, there will be some laser directly through the rust layer, and the laser radiation on the corrosion surface will also transfer part of the energy to the metal substrate surface through heat conduction. By means of experimental analysis on the surface of the metal base, microstructure, mechanical properties and hardness were studied and compared. The results show that the laser derusting process has a good rust removal effect, laser derusting technology does not damage to the metal substrates and the properties of the surface has not been affected..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1210 (2017)
Effect of power on laser cleaning result of stainless steel surface
Guoxing Chen, Haifeng Lu, Ying Zhao, Huiwei Zhang, Shaochong Wei, Hua Ji, Shuhui Wu, and Yiling Shi
Laser cleaning technology was used to clean the surface of stainless steel, and the influence of dif-ferent laser power (300 W, 400 W, 500 W) on cleaning effect was studied. The surface morphology and composi-tion distribution of stainless steel were analyzed by SEM and EDS. The surface roughness and cleaning thick-nesLaser cleaning technology was used to clean the surface of stainless steel, and the influence of dif-ferent laser power (300 W, 400 W, 500 W) on cleaning effect was studied. The surface morphology and composi-tion distribution of stainless steel were analyzed by SEM and EDS. The surface roughness and cleaning thick-ness were detected by White Light Interferometer. The results show that, with the increase of laser power, the ox-ide of stainless steel decomposes and flakes gradually, and the cleaning thickness keeps deepening and reach-es 50 μm at 500 W, which causes partial damage to the matrix. The roughness value decreases firstly and then increases. It reaches a minimum value of 0.38 μm at 400 W. Laser cleaning threshold is approximately 3.96×103W/cm2, and damage threshold is about 5.52×103W/cm2. The best laser cleaning effect of stainless steel is ob-tained when the power is 400 W..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1217 (2017)
Study on etch process of GaSb-based VCSEL
Xin Zhang, Yang Li, Xia Wang, Yang Li, Gangli Yue, Zhiwei Wang, Jianlai Xie, Jiabin Zhang, and Yongqin Hao
2 μm~5 μm GaSb-based VCSEL is an ideal light source for atmospheric detection. However, the im-maturity of its fabrication technology seriously hinders its development. The undercutting effect is the outstanding etch problem in its fabrication. In this paper, Etching characteristics of GaSb is investigated in detail by2 μm~5 μm GaSb-based VCSEL is an ideal light source for atmospheric detection. However, the im-maturity of its fabrication technology seriously hinders its development. The undercutting effect is the outstanding etch problem in its fabrication. In this paper, Etching characteristics of GaSb is investigated in detail by use of phosphoric acid plus tartaric acid solution. In order to compare them, we chose concentration ratio of H3PO4:H2O2:C4H6O6:H2O as 1 mL: 1 mL: 0.3 g: 10 mL, 1 mL: 1 mL: 0.6 g: 10 mL, and 1 mL: 1 mL: 1 g: 10 mL, re-spectively. The testing results from step profiler and scanning electron microscopy (SEM) were compared and analyzed. Etched GaSb in the solution with a concentration ratio of H3PO4:H2O2:C4H6O6:H2O=1:1:0.6:10 shows very good morphology. Undercutting effect was eliminated and a vertical side wall was obtained with no lateral etching. Etching rate is 0.62 μm/min. The perfect etch behavior of GaSb provides a good technical support for laser preparation..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1225 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1230 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1231 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1232 (2017)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1233 (2017)
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1234 (2017)
Study on etch process of GaSb-based VCSEL
Xin Zhang, Yang Li, Xia Wang, Yang Li, Gangli Yue, Zhiwei Wang, Jianlai Xie, Jiabin Zhang, and Yongqin Hao
2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light sou2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light source for the molecular spectrum measurement, biochemical testing, laser radar, thermal imaging and medical diagnosis. For example, in the TDLAS (tunable laser diode absorption spectroscopy test) system for monitoring polluting gases CO, CH4, NH3and HF, the use of VCSEL as a light source will greatly reduce the complexity and the cost for no beam shaping and easily coupled packaging, and shrink the size of the system. Furthermore, its modulation rate can reach several tens of Gbit/s, so it is considered to be the best alternative device of distributed feedback (DFB) laser in the future. As the GaSb material can cover the entire mid-infrared band, it is the best material system for the development of 2 μm~5 μm mid-infrared VCSEL..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1244 (2017)
Study on etch process of GaSb-based VCSEL
Xin Zhang, Yang Li, Xia Wang, Yang Li, Gangli Yue, Zhiwei Wang, Jianlai Xie, Jiabin Zhang, and Yongqin Hao
2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light sou2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light source for the molecular spectrum measurement, biochemical testing, laser radar, thermal imaging and medical diagnosis. For example, in the TDLAS (tunable laser diode absorption spectroscopy test) system for monitoring polluting gases CO, CH4, NH3and HF, the use of VCSEL as a light source will greatly reduce the complexity and the cost for no beam shaping and easily coupled packaging, and shrink the size of the system. Furthermore, its modulation rate can reach several tens of Gbit/s, so it is considered to be the best alternative device of distributed feedback (DFB) laser in the future. As the GaSb material can cover the entire mid-infrared band, it is the best material system for the development of 2 μm~5 μm mid-infrared VCSEL..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1244 (2017)
Study on etch process of GaSb-based VCSEL
Xin Zhang, Yang Li, Xia Wang, Yang Li, Gangli Yue, Zhiwei Wang, Jianlai Xie, Jiabin Zhang, and Yongqin Hao
2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light sou2 μm~5 μm mid-infrared vertical cavity surface emitting laser (VCSEL), featured with advantages of low power con-sumption, small divergence angle, no astigmatism circular spot, high modulation bandwidth, wavelength stability, low production cost, and high density ultra-small dimensional packaging, is an ideal light source for the molecular spectrum measurement, biochemical testing, laser radar, thermal imaging and medical diagnosis. For example, in the TDLAS (tunable laser diode absorption spectroscopy test) system for monitoring polluting gases CO, CH4, NH3and HF, the use of VCSEL as a light source will greatly reduce the complexity and the cost for no beam shaping and easily coupled packaging, and shrink the size of the system. Furthermore, its modulation rate can reach several tens of Gbit/s, so it is considered to be the best alternative device of distributed feedback (DFB) laser in the future. As the GaSb material can cover the entire mid-infrared band, it is the best material system for the development of 2 μm~5 μm mid-infrared VCSEL..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1244 (2017)
Effect of power on laser cleaning result of stainless steel surface
Guoxing Chen, Haifeng Lu, Ying Zhao, Huiwei Zhang, Shaochong Wei, Hua Ji, Shuhui Wu, and Yiling Shi
Laser cleaning has been widely used in many industrial fields because of its high efficiency and no second waste. From this point of view, laser cleaning has promising applications for removal of corroded layer in stainless steel pipe in nu-clear plants, compared with conventional chemical and mechanical methods. In thLaser cleaning has been widely used in many industrial fields because of its high efficiency and no second waste. From this point of view, laser cleaning has promising applications for removal of corroded layer in stainless steel pipe in nu-clear plants, compared with conventional chemical and mechanical methods. In this work, systematic laser cleaning experiment of oxide on stainless steel was conducted, and the effect of different laser power (300 W, 400 W, 500 W) on cleaning effect was studied, which obtained the optimum processing parameters on this account. The surface mor-phology and composition distribution of stainless steel are analyzed by SEM and EDS before and after laser cleaning. The surface roughness was measured by white light interferometer and the removal thickness of oxide was evaluated by the sectional step height. The main results show that: 1) the oxide of stainless steel decomposes and flakes gradually with the increase of power, and the substrate is partly damaged while power exceeds 400 W. The amount of oxide in-creases instead at 500 W, because high power can cause laser ablation, resulting in a serious oxidation of the matrix; the content of element is mainly O and Fe at 300 W, and then the content of Cr increases continuously and is con-sistent with that of substrate finally; 2) The cleaning removal thickness increases from 17 μm to 50 μm with laser power; 3) The roughness value Ra is 3.44 μm before laser cleaning, while the roughness value decreases firstly and then in-creases, and reaches a minimum value of 0.38 μm at 400 W after cleaning; 4) The cleaning force produced by laser cleaning is the key to decontamination. Power density is the concrete data representation of cleaning force. The value of cleaning threshold and damage threshold is obtained by combining power density and experimental analysis. In order to get more accurate data, the experiments of other power (250 W, 280 W, 350 W, and 380 W) are carried out as supplementary. The oxide of stainless steel begins to expand and peel off under a 280 W laser, thus the cleaning threshold is approximately equal to the power density at this point, which is 3.96×103W/cm2.The laser cleaning starts to touching substrate and causes some damage to it when the power increases to 380 W, which is similar to that of 400 W. Therefore, the average power density of 380 W and 400 W is determined as the damage threshold, and the specific value is 5.52×103W/cm2. While the power is about 400 W, frequency is 10 kHz, speed is 30 °/h, scan frequency is 5 times, and the laser cleaning obtains the best effect after comprehensive comparison and analysis..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1245 (2017)
Mechanism of laser derusting and surface properties of low carbon steel
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Laser cleaning technology is very useful and promising in mechanical industry, micro-electronic industry, artwork res-toration and other special areas, which has attracted great attention among researchers. Many experimental and theo-retical studies on laser cleaning have been carried out in the past years. Low steel hLaser cleaning technology is very useful and promising in mechanical industry, micro-electronic industry, artwork res-toration and other special areas, which has attracted great attention among researchers. Many experimental and theo-retical studies on laser cleaning have been carried out in the past years. Low steel has wide application. But for some low steels in an environment prone to rust, traditional rust removing methods can be replaced by laser derusting tech-nology, which has a broad prospect. The corrosion surface of the laser radiation has the characteristics of high laser energy and short pulse, so that the corrosion temperature quickly reaches above the melting point. So laser derusting is mainly through the ablation mechanism to achieve cleaning effect. The corrosion of low carbon steel is mainly com-posed of the mixture of Fe oxide and its hydrate, and the surface oxygen content can be used to effectively character-ize the effect of rust removal. The laser spot area is much smaller than the cleaning corrosion area and the laser pulse has short pulse width, so that the range of laser heat conduction is very small in the plane direction. It can be consid-ered that the plane direction has uniform heat, so the Fourier heat conduction model is used to characterize the corro-sion of surface heat conduction. In fact, when a laser beam irradiates the rust layer surface, it can not only remove the rust layer but also influence the performance of the cleaned surface. At the same time of laser rust removal, there will be some laser directly through the rust layer, and the laser radiation on the corrosion surface will also transfer part of the energy to the metal substrate surface through heat conduction. By means of experimental analysis on the surface of the metal base, microstructure, mechanical properties and hardness were studied and compared that indicate laser derusting technology does not damage to the metal substrates and the properties of the surface has not been affected. Laser derusting has little effect on metal, so the mechanical properties of metal substrate are characterized by using technology instrumented indentation technique. The technique needs to measure the load and displacement data dur-ing the whole indentation process and plot the load-displacement curve (P-h curve). And then, mechanical properties, such as elastic modulus, yield strength, ultimate tensile strength, strain hardening exponent and extension ratio, can be calculated from the P-h curve with the specific algorithm..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1246 (2017)
Mechanism of laser derusting and surface properties of low carbon steel
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Laser cleaning technology is very useful and promising in mechanical industry, micro-electronic industry, artwork res-toration and other special areas, which has attracted great attention among researchers. Many experimental and theo-retical studies on laser cleaning have been carried out in the past years. Low steel hLaser cleaning technology is very useful and promising in mechanical industry, micro-electronic industry, artwork res-toration and other special areas, which has attracted great attention among researchers. Many experimental and theo-retical studies on laser cleaning have been carried out in the past years. Low steel has wide application. But for some low steels in an environment prone to rust, traditional rust removing methods can be replaced by laser derusting tech-nology, which has a broad prospect. The corrosion surface of the laser radiation has the characteristics of high laser energy and short pulse, so that the corrosion temperature quickly reaches above the melting point. So laser derusting is mainly through the ablation mechanism to achieve cleaning effect. The corrosion of low carbon steel is mainly com-posed of the mixture of Fe oxide and its hydrate, and the surface oxygen content can be used to effectively character-ize the effect of rust removal. The laser spot area is much smaller than the cleaning corrosion area and the laser pulse has short pulse width, so that the range of laser heat conduction is very small in the plane direction. It can be consid-ered that the plane direction has uniform heat, so the Fourier heat conduction model is used to characterize the corro-sion of surface heat conduction. In fact, when a laser beam irradiates the rust layer surface, it can not only remove the rust layer but also influence the performance of the cleaned surface. At the same time of laser rust removal, there will be some laser directly through the rust layer, and the laser radiation on the corrosion surface will also transfer part of the energy to the metal substrate surface through heat conduction. By means of experimental analysis on the surface of the metal base, microstructure, mechanical properties and hardness were studied and compared that indicate laser derusting technology does not damage to the metal substrates and the properties of the surface has not been affected. Laser derusting has little effect on metal, so the mechanical properties of metal substrate are characterized by using technology instrumented indentation technique. The technique needs to measure the load and displacement data dur-ing the whole indentation process and plot the load-displacement curve (P-h curve). And then, mechanical properties, such as elastic modulus, yield strength, ultimate tensile strength, strain hardening exponent and extension ratio, can be calculated from the P-h curve with the specific algorithm..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1246 (2017)
Picosecond laser microfabrication of infrared antireflective functional surface on As2Se3glass
Qiang Yang, Lingfei Ji, Bo Xu, Tianyang Yan, Wenhao Wang1, and Zhenyuan Lin
Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system.Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system. In order to decrease the large reflection losses, researches on multi-layer thin-film coatings for anti-reflection (AR) with good performance were performed. However, disadvantages of the method are needed to be overcome, such as high costs and short lifetimes. Recently, surface micro-structures have been shown to be a good alternative potential to multi-layer thin-film AR coatings in many infrared and visible-band applications..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1247 (2017)
Picosecond laser microfabrication of infrared antireflective functional surface on As2Se3glass
Qiang Yang, Lingfei Ji, Bo Xu, Tianyang Yan, Wenhao Wang1, and Zhenyuan Lin
Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system.Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system. In order to decrease the large reflection losses, researches on multi-layer thin-film coatings for anti-reflection (AR) with good performance were performed. However, disadvantages of the method are needed to be overcome, such as high costs and short lifetimes. Recently, surface micro-structures have been shown to be a good alternative potential to multi-layer thin-film AR coatings in many infrared and visible-band applications..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1247 (2017)
Picosecond laser microfabrication of infrared antireflective functional surface on As2Se3glass
Qiang Yang, Lingfei Ji, Bo Xu, Tianyang Yan, Wenhao Wang1, and Zhenyuan Lin
Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system.Chalcogenide glasses are formed of chalcogen of S, Se, Te with doping of a certain of other metal elements. Due to the lower refractive index, temperature coefficient and good infrared transmittance, it has been recognized as the ideal materials for a new generation temperature non-refrigerated infrared optical system. In order to decrease the large reflection losses, researches on multi-layer thin-film coatings for anti-reflection (AR) with good performance were performed. However, disadvantages of the method are needed to be overcome, such as high costs and short lifetimes. Recently, surface micro-structures have been shown to be a good alternative potential to multi-layer thin-film AR coatings in many infrared and visible-band applications..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1247 (2017)
Effect of constant temperature substrate on microstructure and hardness of Al2O3-based eutectic ceramics
Hanchao Liu, Fan Lu, Guangyi Ma, and Dongjiang Wu
Al2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stabilAl2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stability. Al2O3-YAG eutectic ceramic thin-wall samples were prepared by laser engineered net shaping using Al2O3and Y2O3 powders as raw materials. During the process of the laser engineered net shaping, the heat transfers to substrate and the heat accumulation is serious. According to this characteristic, a water-cooled constant temperature substrate was designed to change the temperature gradient and the cooling condition in the forming process. Al2O3-YAG eutectic ceramic thin-wall samples forming ex-periments were carried out on a common substrate and a water-cooled constant temperature substrate with the same laser power, scanning velocity, powder feeding rate and Z increment. The common substrate is TC4 substrate, while the water-cooled constant temperature substrate is composed of aluminum alloy cooling block, TC4 substrate, and plastic hose. The thermal plastic ensures the good contact between the TC4 substrate and aluminum alloy cooling block, and the heat accumulated on the TC4 substrate is rapidly dissipated through the aluminum alloy cooling block in which the constant temperature cooling water of 28 ℃ circulates. The Al2O3-YAG thin-wall samples prepared on different sub-strates were obtained, and their macro-morphology, microstructure and microhardness were compared. The results show that the water-cooled constant temperature substrate has a significant effect on the microstructure and eutectic spacing of Al2O3-YAG eutectic ceramic. The microstructure of thin-wall sample prepared on the common substrate is three-dimensional network structure with an average eutectic spacing of 0.96 μm. And the microstructure of top part of the sample prepared on the water-cooled constant temperature substrate is colony structure, while the microstructure of bottom part is dendrite structure which grows in the reverse direction of the heat flow. The average eutectic spacing of samples prepared on the water-cooled substrate has reduced to 0.21 μm. It is concluded that the morphological change of microstructures is mainly related to the degree of supercooling. The decrease of eutectic spacing is mainly due to the fact that the solidification rate is inversely proportional to the eutectic spacing. The applications of water-cooled con-stant temperature substrate can effectively improve the solidification rate, so the eutectic spacing decreases with the increase of the solidification rate. Comparing the microhardness of thin-wall samples prepared on the different sub-strates, the microhardness of the thin–wall sample prepared on the water-cooled constant temperature substrate is in-creased by about 10% due to the increase of the solidification rate and temperature gradient, the decrease of the eutec-tic spacing, grain refinement and the interaction between eutectic phase and cracks..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1248 (2017)
Effect of constant temperature substrate on microstructure and hardness of Al2O3-based eutectic ceramics
Hanchao Liu, Fan Lu, Guangyi Ma, and Dongjiang Wu
Al2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stabilAl2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stability. Al2O3-YAG eutectic ceramic thin-wall samples were prepared by laser engineered net shaping using Al2O3and Y2O3 powders as raw materials. During the process of the laser engineered net shaping, the heat transfers to substrate and the heat accumulation is serious. According to this characteristic, a water-cooled constant temperature substrate was designed to change the temperature gradient and the cooling condition in the forming process. Al2O3-YAG eutectic ceramic thin-wall samples forming ex-periments were carried out on a common substrate and a water-cooled constant temperature substrate with the same laser power, scanning velocity, powder feeding rate and Z increment. The common substrate is TC4 substrate, while the water-cooled constant temperature substrate is composed of aluminum alloy cooling block, TC4 substrate, and plastic hose. The thermal plastic ensures the good contact between the TC4 substrate and aluminum alloy cooling block, and the heat accumulated on the TC4 substrate is rapidly dissipated through the aluminum alloy cooling block in which the constant temperature cooling water of 28 ℃ circulates. The Al2O3-YAG thin-wall samples prepared on different sub-strates were obtained, and their macro-morphology, microstructure and microhardness were compared. The results show that the water-cooled constant temperature substrate has a significant effect on the microstructure and eutectic spacing of Al2O3-YAG eutectic ceramic. The microstructure of thin-wall sample prepared on the common substrate is three-dimensional network structure with an average eutectic spacing of 0.96 μm. And the microstructure of top part of the sample prepared on the water-cooled constant temperature substrate is colony structure, while the microstructure of bottom part is dendrite structure which grows in the reverse direction of the heat flow. The average eutectic spacing of samples prepared on the water-cooled substrate has reduced to 0.21 μm. It is concluded that the morphological change of microstructures is mainly related to the degree of supercooling. The decrease of eutectic spacing is mainly due to the fact that the solidification rate is inversely proportional to the eutectic spacing. The applications of water-cooled con-stant temperature substrate can effectively improve the solidification rate, so the eutectic spacing decreases with the increase of the solidification rate. Comparing the microhardness of thin-wall samples prepared on the different sub-strates, the microhardness of the thin–wall sample prepared on the water-cooled constant temperature substrate is in-creased by about 10% due to the increase of the solidification rate and temperature gradient, the decrease of the eutec-tic spacing, grain refinement and the interaction between eutectic phase and cracks..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1248 (2017)
Effect of constant temperature substrate on microstructure and hardness of Al2O3-based eutectic ceramics
Hanchao Liu, Fan Lu, Guangyi Ma, and Dongjiang Wu
Al2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stabilAl2O3-YAG eutectic ceramic has been considered as one of the most potential alternatives to current traditional super-alloys applied in the aerospace field due to its extremely excellent high temperature mechanical properties, such as high temperature strength, oxidation resistance and high temperature structure stability. Al2O3-YAG eutectic ceramic thin-wall samples were prepared by laser engineered net shaping using Al2O3and Y2O3 powders as raw materials. During the process of the laser engineered net shaping, the heat transfers to substrate and the heat accumulation is serious. According to this characteristic, a water-cooled constant temperature substrate was designed to change the temperature gradient and the cooling condition in the forming process. Al2O3-YAG eutectic ceramic thin-wall samples forming ex-periments were carried out on a common substrate and a water-cooled constant temperature substrate with the same laser power, scanning velocity, powder feeding rate and Z increment. The common substrate is TC4 substrate, while the water-cooled constant temperature substrate is composed of aluminum alloy cooling block, TC4 substrate, and plastic hose. The thermal plastic ensures the good contact between the TC4 substrate and aluminum alloy cooling block, and the heat accumulated on the TC4 substrate is rapidly dissipated through the aluminum alloy cooling block in which the constant temperature cooling water of 28 ℃ circulates. The Al2O3-YAG thin-wall samples prepared on different sub-strates were obtained, and their macro-morphology, microstructure and microhardness were compared. The results show that the water-cooled constant temperature substrate has a significant effect on the microstructure and eutectic spacing of Al2O3-YAG eutectic ceramic. The microstructure of thin-wall sample prepared on the common substrate is three-dimensional network structure with an average eutectic spacing of 0.96 μm. And the microstructure of top part of the sample prepared on the water-cooled constant temperature substrate is colony structure, while the microstructure of bottom part is dendrite structure which grows in the reverse direction of the heat flow. The average eutectic spacing of samples prepared on the water-cooled substrate has reduced to 0.21 μm. It is concluded that the morphological change of microstructures is mainly related to the degree of supercooling. The decrease of eutectic spacing is mainly due to the fact that the solidification rate is inversely proportional to the eutectic spacing. The applications of water-cooled con-stant temperature substrate can effectively improve the solidification rate, so the eutectic spacing decreases with the increase of the solidification rate. Comparing the microhardness of thin-wall samples prepared on the different sub-strates, the microhardness of the thin–wall sample prepared on the water-cooled constant temperature substrate is in-creased by about 10% due to the increase of the solidification rate and temperature gradient, the decrease of the eutec-tic spacing, grain refinement and the interaction between eutectic phase and cracks..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1248 (2017)
Fabrication and bacterial adhesion of metal dry electrode with surface microstructure arrays
Shaoyu Liu, Wei Zhou, Yaoyao Li, Jiachang Fang, Chenying Zhang, Ronghua Lu, and Guifeng Ye
Biomedical electrodes can convert ion potential of the human body into external electron potential, which are widely used in medical detection and clinical applications such as electrocardiogram (ECG), electromyogram (EMG), electro-encephalogram (EEG) and bioelectrical impedance (EIT), etc. Conventional Ag/AgCl wet eleBiomedical electrodes can convert ion potential of the human body into external electron potential, which are widely used in medical detection and clinical applications such as electrocardiogram (ECG), electromyogram (EMG), electro-encephalogram (EEG) and bioelectrical impedance (EIT), etc. Conventional Ag/AgCl wet electrodes usually have con-ductive gel on its surface and stable signal baseline. However, the conductive gel is easy to gradually dry up and cause allergic phenomenon. Thus, the Ag/AgCl wet electrodes are not suitable for long-time measurement and monitoring of bioelectric signals. Microneedles electrodes can overcome the shortcomings of the Ag/AgCl wet electrode, which can contact the tissue with lower impedance, to improve the quality of bioelectrical signal detection. In this study, the laser milling-recasting technology was proposed to fabricate metal dry electrodes with surface microstructure arrays. Based on the analysis of the microcosmic appearance of the electrode surface, the wettability of the electrode surface were firstly discussed, and then the influence of scanning spacing, scanning speed and scanning times of laser processing parameters on the adhesion of Escherichia coli were further investigated. The results show that the contact angle of metal dry electrode with surface microstructure arrays fabricated with reasonable laser processing parameter could reach more than 150° and showed the superhydrophobic characteristics. With the scanning spacing of 0.1 mm, the smallest averager radius of microstructure on the surface of the metal dry electrode was obtained to limit the biofilm growth, which showed the best performance against the adhesion of Escherichia coli. However, the metal dry electrode adhered more Escherichia coli when the larger scanning spacing was selected. When small scanning times was selected, the metal dry electrodes had much lower height of the surface microstructure, and the larger adhesion amount of esch-erichia coli was obtained due to its poorer hydrophobicity. With the increasing scanning times, the adhesion amount of escherichia coli of metal dry electrode can be reduced. The scanned speed has little influence on the hydrophobicity and the adhesion ability of Escherichia coli because the shape of the microstructure was not changed greatly with dif-ferent scanning speeds. Taking into account the performance and economic requirements of the metal dry electrode, the optimized processing parameters including 0.1 mm scanning spacing, 1000 mm/s scanning speed, 15 scanning times and 25 W laser output power were recommend. The metal dry electrode with surface microstructure arrays shows hydrophobicity characteristics against the adhesion of Escherichia coli compared with others bioelectrodes, which have an important application prospects for long-time detection of bioelectricity measurement..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1249 (2017)
Fabrication and bacterial adhesion of metal dry electrode with surface microstructure arrays
Shaoyu Liu, Wei Zhou, Yaoyao Li, Jiachang Fang, Chenying Zhang, Ronghua Lu, and Guifeng Ye
Biomedical electrodes can convert ion potential of the human body into external electron potential, which are widely used in medical detection and clinical applications such as electrocardiogram (ECG), electromyogram (EMG), electro-encephalogram (EEG) and bioelectrical impedance (EIT), etc. Conventional Ag/AgCl wet eleBiomedical electrodes can convert ion potential of the human body into external electron potential, which are widely used in medical detection and clinical applications such as electrocardiogram (ECG), electromyogram (EMG), electro-encephalogram (EEG) and bioelectrical impedance (EIT), etc. Conventional Ag/AgCl wet electrodes usually have con-ductive gel on its surface and stable signal baseline. However, the conductive gel is easy to gradually dry up and cause allergic phenomenon. Thus, the Ag/AgCl wet electrodes are not suitable for long-time measurement and monitoring of bioelectric signals. Microneedles electrodes can overcome the shortcomings of the Ag/AgCl wet electrode, which can contact the tissue with lower impedance, to improve the quality of bioelectrical signal detection. In this study, the laser milling-recasting technology was proposed to fabricate metal dry electrodes with surface microstructure arrays. Based on the analysis of the microcosmic appearance of the electrode surface, the wettability of the electrode surface were firstly discussed, and then the influence of scanning spacing, scanning speed and scanning times of laser processing parameters on the adhesion of Escherichia coli were further investigated. The results show that the contact angle of metal dry electrode with surface microstructure arrays fabricated with reasonable laser processing parameter could reach more than 150° and showed the superhydrophobic characteristics. With the scanning spacing of 0.1 mm, the smallest averager radius of microstructure on the surface of the metal dry electrode was obtained to limit the biofilm growth, which showed the best performance against the adhesion of Escherichia coli. However, the metal dry electrode adhered more Escherichia coli when the larger scanning spacing was selected. When small scanning times was selected, the metal dry electrodes had much lower height of the surface microstructure, and the larger adhesion amount of esch-erichia coli was obtained due to its poorer hydrophobicity. With the increasing scanning times, the adhesion amount of escherichia coli of metal dry electrode can be reduced. The scanned speed has little influence on the hydrophobicity and the adhesion ability of Escherichia coli because the shape of the microstructure was not changed greatly with dif-ferent scanning speeds. Taking into account the performance and economic requirements of the metal dry electrode, the optimized processing parameters including 0.1 mm scanning spacing, 1000 mm/s scanning speed, 15 scanning times and 25 W laser output power were recommend. The metal dry electrode with surface microstructure arrays shows hydrophobicity characteristics against the adhesion of Escherichia coli compared with others bioelectrodes, which have an important application prospects for long-time detection of bioelectricity measurement..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1249 (2017)
Microtube fabrication based on femtosecond Bessel beam and its flexible driving with external magnetic field
Chen Xin, Liang Yang, Zhijiang Hu, Kai Hu, Dongdong Qian, Yanlei Hu, Jiawen Li, and Dong Wu
Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such as directed drug delivery, isolation of biological targets, microsurgery, bioassay, bioimaging, environmental monitoring, remediation processes, and so on. But current fabrication methods such as self-rolling of organic or inorganic films, accumulation of nanoparticles, mask-based diffraction lithography and holographic lithography are only suitable for the preparation of microtubes with certain periodic or specific profiles due to the limitation of inherent fabrication principles, and thus suffered from low flexibility and weak designability. We present a method for the fabrication of magnetic drivable microtubes, by direct femtosecond laser writing combined with magnetron sputtering with metal layer. Femtosecond laser beam is modulated into Bessel beam with spatial light modulator (SLM), and then Bessel beam is focused with a high numeri-cal aperture objective. Microtubes are fabricated by scanning focused femtosecond Bessel beam, a circular beam pat-tern, in a sample anchored on a three dimension stage. This technology keeps the high resolution of two-photon polymerization and greatly reduces the consumed time by two magnitudes. Followed by magnetron sputtering a nickel layer, the microtubes exhibit paramagnetic property and can be flexibly driven by external magnetic field. The propa-gation and high numerical aperture focusing properties of femtosecond Bessel beams are investigated, which constructs a solid base for the fabrication parameters optimization. By modulating the phase hologram loaded to the SLM, the intensity distribution of femtosecond laser beam is controlled. Microtubes, with well controlled diameter, length and distribution are efficiently fabricated. Complicated microtube arrays, including 2×1, 2×2 arrays, 5 tubes microrocket and 9 tubes microrocket are fabricated rapidly within several seconds. Individual microtube in these arrays keeps its original shape without any deformation and interaction with each other. A sputtered 80 nm Ni layer imposes the micro-tubes with paramagnetic property. Rapid steering of the nickel coated microtubes along specific route in fluid environ-ment with external magnetic field produced by columnar magnet has been realized. Controlled driving of microtubes along a “NANO” type trajectory has been achieved. The magnetic driving of microtubes will not be affected by envi-ronmental variation, electric signal, temperature signal and optical signal. This method is flexible, controllable as well as efficient, and the fabricated drivable microtubes have promising applications in noninvasive surgery, targeted drug de-livery, bioimaging or biosensing and microenvironment cleaning..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1250 (2017)
Microtube fabrication based on femtosecond Bessel beam and its flexible driving with external magnetic field
Chen Xin, Liang Yang, Zhijiang Hu, Kai Hu, Dongdong Qian, Yanlei Hu, Jiawen Li, and Dong Wu
Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such as directed drug delivery, isolation of biological targets, microsurgery, bioassay, bioimaging, environmental monitoring, remediation processes, and so on. But current fabrication methods such as self-rolling of organic or inorganic films, accumulation of nanoparticles, mask-based diffraction lithography and holographic lithography are only suitable for the preparation of microtubes with certain periodic or specific profiles due to the limitation of inherent fabrication principles, and thus suffered from low flexibility and weak designability. We present a method for the fabrication of magnetic drivable microtubes, by direct femtosecond laser writing combined with magnetron sputtering with metal layer. Femtosecond laser beam is modulated into Bessel beam with spatial light modulator (SLM), and then Bessel beam is focused with a high numeri-cal aperture objective. Microtubes are fabricated by scanning focused femtosecond Bessel beam, a circular beam pat-tern, in a sample anchored on a three dimension stage. This technology keeps the high resolution of two-photon polymerization and greatly reduces the consumed time by two magnitudes. Followed by magnetron sputtering a nickel layer, the microtubes exhibit paramagnetic property and can be flexibly driven by external magnetic field. The propa-gation and high numerical aperture focusing properties of femtosecond Bessel beams are investigated, which constructs a solid base for the fabrication parameters optimization. By modulating the phase hologram loaded to the SLM, the intensity distribution of femtosecond laser beam is controlled. Microtubes, with well controlled diameter, length and distribution are efficiently fabricated. Complicated microtube arrays, including 2×1, 2×2 arrays, 5 tubes microrocket and 9 tubes microrocket are fabricated rapidly within several seconds. Individual microtube in these arrays keeps its original shape without any deformation and interaction with each other. A sputtered 80 nm Ni layer imposes the micro-tubes with paramagnetic property. Rapid steering of the nickel coated microtubes along specific route in fluid environ-ment with external magnetic field produced by columnar magnet has been realized. Controlled driving of microtubes along a “NANO” type trajectory has been achieved. The magnetic driving of microtubes will not be affected by envi-ronmental variation, electric signal, temperature signal and optical signal. This method is flexible, controllable as well as efficient, and the fabricated drivable microtubes have promising applications in noninvasive surgery, targeted drug de-livery, bioimaging or biosensing and microenvironment cleaning..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1250 (2017)
Microtube fabrication based on femtosecond Bessel beam and its flexible driving with external magnetic field
Chen Xin, Liang Yang, Zhijiang Hu, Kai Hu, Dongdong Qian, Yanlei Hu, Jiawen Li, and Dong Wu
Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such Microtube, with simple and uniform geometry, is one of the basic structures in micro/nano field. Mircotube is widely used in the fields of microoptics, biomedical devices, microfluidics, micropumps, microsensors and micromotors, espe-cially magnetically driven motors are envisioned to be involved in various tasks such as directed drug delivery, isolation of biological targets, microsurgery, bioassay, bioimaging, environmental monitoring, remediation processes, and so on. But current fabrication methods such as self-rolling of organic or inorganic films, accumulation of nanoparticles, mask-based diffraction lithography and holographic lithography are only suitable for the preparation of microtubes with certain periodic or specific profiles due to the limitation of inherent fabrication principles, and thus suffered from low flexibility and weak designability. We present a method for the fabrication of magnetic drivable microtubes, by direct femtosecond laser writing combined with magnetron sputtering with metal layer. Femtosecond laser beam is modulated into Bessel beam with spatial light modulator (SLM), and then Bessel beam is focused with a high numeri-cal aperture objective. Microtubes are fabricated by scanning focused femtosecond Bessel beam, a circular beam pat-tern, in a sample anchored on a three dimension stage. This technology keeps the high resolution of two-photon polymerization and greatly reduces the consumed time by two magnitudes. Followed by magnetron sputtering a nickel layer, the microtubes exhibit paramagnetic property and can be flexibly driven by external magnetic field. The propa-gation and high numerical aperture focusing properties of femtosecond Bessel beams are investigated, which constructs a solid base for the fabrication parameters optimization. By modulating the phase hologram loaded to the SLM, the intensity distribution of femtosecond laser beam is controlled. Microtubes, with well controlled diameter, length and distribution are efficiently fabricated. Complicated microtube arrays, including 2×1, 2×2 arrays, 5 tubes microrocket and 9 tubes microrocket are fabricated rapidly within several seconds. Individual microtube in these arrays keeps its original shape without any deformation and interaction with each other. A sputtered 80 nm Ni layer imposes the micro-tubes with paramagnetic property. Rapid steering of the nickel coated microtubes along specific route in fluid environ-ment with external magnetic field produced by columnar magnet has been realized. Controlled driving of microtubes along a “NANO” type trajectory has been achieved. The magnetic driving of microtubes will not be affected by envi-ronmental variation, electric signal, temperature signal and optical signal. This method is flexible, controllable as well as efficient, and the fabricated drivable microtubes have promising applications in noninvasive surgery, targeted drug de-livery, bioimaging or biosensing and microenvironment cleaning..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1250 (2017)
Review of UV laser and its applications in micromachining
Shilin Nie, and Yingchun Guan
Ultraviolet(UV) laser with its short wavelength, high machining accuracy and cold processing property, has unique ad-vantages in micromachining, and can effectively improve the manufacturing quality. Modern electronic industry has achieved a rapid development in recent years, and sets higher demands in fabricating. UV Ultraviolet(UV) laser with its short wavelength, high machining accuracy and cold processing property, has unique ad-vantages in micromachining, and can effectively improve the manufacturing quality. Modern electronic industry has achieved a rapid development in recent years, and sets higher demands in fabricating. UV laser’s progress and applica-tions in electronic industry attracts are attracting broad attention. UV laser can process complex structures on almost any materials with flexible process and small heat-affected zone. It summarizes the development of UV laser. The fundamental principles and characteristics of excimer laser and diode pumped solid state laser are given, which are two major UV lasers used for micromachining. The development and applications of UV laser in the micromachining of semiconductor, optical element and polymer are introduced. It gives some prospects and forecasts about research in the further development..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1251 (2017)
Review of UV laser and its applications in micromachining
Shilin Nie, and Yingchun Guan
Ultraviolet(UV) laser with its short wavelength, high machining accuracy and cold processing property, has unique ad-vantages in micromachining, and can effectively improve the manufacturing quality. Modern electronic industry has achieved a rapid development in recent years, and sets higher demands in fabricating. UV Ultraviolet(UV) laser with its short wavelength, high machining accuracy and cold processing property, has unique ad-vantages in micromachining, and can effectively improve the manufacturing quality. Modern electronic industry has achieved a rapid development in recent years, and sets higher demands in fabricating. UV laser’s progress and applica-tions in electronic industry attracts are attracting broad attention. UV laser can process complex structures on almost any materials with flexible process and small heat-affected zone. It summarizes the development of UV laser. The fundamental principles and characteristics of excimer laser and diode pumped solid state laser are given, which are two major UV lasers used for micromachining. The development and applications of UV laser in the micromachining of semiconductor, optical element and polymer are introduced. It gives some prospects and forecasts about research in the further development..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1251 (2017)
Research progress in superhydrophobic surfaces fabricated by laser
Huan Yang, Yu Cao, Fengping Li, and Wei Xue
Superhydrophobic surfaces, which are defined by the water contact angle higher than 150° and the slide angle lower than 10°, have recently attracted more and more attention due to their important applications in anti-corrosion, oil-water separation, friction reduction, and liquid transportation. Over the pastSuperhydrophobic surfaces, which are defined by the water contact angle higher than 150° and the slide angle lower than 10°, have recently attracted more and more attention due to their important applications in anti-corrosion, oil-water separation, friction reduction, and liquid transportation. Over the past few decades, many methods have been developed to fabricate superhydrophobic surfaces which can usually be achieved by creating a rough surface structure on a hydrophobic material or depositing a layer of chemical molecules with low surface energy onto a rough surface, so surface morphology is a key factor to determine the wettability of a solid surface, and patterning is one of the effective ways to change the surface morphology and to improve the wetting properties. Laser patterning using a pulse laser source is a unique technique that can modify the surface morphology with very limited distortion of the bulk material. Moreover, it is a noncontact method, and complex patterns can be created. The basic wettability theory of solid sur-face was introduced, such as Young equation, Wenzel model, Cassie-Baxter model, wetting courses and conditions. As the surperhydrophobicity depends on the surface microstructure of materials, and the pulse width is one of the key factors affecting the processing accuracy and quality of laser fabricated microstructure, the research progress in the superhydrophobic surfaces fabricated by laser was classified based on the laser pulse width (nanosecond, picosecond and femtosecond). Several typical approaches of laser fabricated superhydrophobic surfaces were summarized, in-cluding the laser texturing and subsequent surface modified technologies, meanwhile the surface morphologies and wetting properties of the surperhydrophobic surfaces fabricated with different laser pulse width were compared, and the relevant applications were also presented. The cost of nanosecond laser is relatively low, but the processing accuracy is restricted by the diffraction theory, and the nanosecond laser is not suitable for fabricating superhydrophobic surface on hard-brittle transparent materials, so as on low-melting materials. The nonlinear absorption effect of femtosecond laser could obtain the processing accuracy which is much smaller than the focal spot, meanwhile depending on this effect, microstructure superhydrophobic surfaces could be fabricated on almost all the solid materials. Although the research in the field of superhydrophobic surfaces has been conducted for over ten years, the fabricating cost and du-rability still could not meet the requirements of industrial application..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1252 (2017)
Research progress in superhydrophobic surfaces fabricated by laser
Huan Yang, Yu Cao, Fengping Li, and Wei Xue
Superhydrophobic surfaces, which are defined by the water contact angle higher than 150° and the slide angle lower than 10°, have recently attracted more and more attention due to their important applications in anti-corrosion, oil-water separation, friction reduction, and liquid transportation. Over the pastSuperhydrophobic surfaces, which are defined by the water contact angle higher than 150° and the slide angle lower than 10°, have recently attracted more and more attention due to their important applications in anti-corrosion, oil-water separation, friction reduction, and liquid transportation. Over the past few decades, many methods have been developed to fabricate superhydrophobic surfaces which can usually be achieved by creating a rough surface structure on a hydrophobic material or depositing a layer of chemical molecules with low surface energy onto a rough surface, so surface morphology is a key factor to determine the wettability of a solid surface, and patterning is one of the effective ways to change the surface morphology and to improve the wetting properties. Laser patterning using a pulse laser source is a unique technique that can modify the surface morphology with very limited distortion of the bulk material. Moreover, it is a noncontact method, and complex patterns can be created. The basic wettability theory of solid sur-face was introduced, such as Young equation, Wenzel model, Cassie-Baxter model, wetting courses and conditions. As the surperhydrophobicity depends on the surface microstructure of materials, and the pulse width is one of the key factors affecting the processing accuracy and quality of laser fabricated microstructure, the research progress in the superhydrophobic surfaces fabricated by laser was classified based on the laser pulse width (nanosecond, picosecond and femtosecond). Several typical approaches of laser fabricated superhydrophobic surfaces were summarized, in-cluding the laser texturing and subsequent surface modified technologies, meanwhile the surface morphologies and wetting properties of the surperhydrophobic surfaces fabricated with different laser pulse width were compared, and the relevant applications were also presented. The cost of nanosecond laser is relatively low, but the processing accuracy is restricted by the diffraction theory, and the nanosecond laser is not suitable for fabricating superhydrophobic surface on hard-brittle transparent materials, so as on low-melting materials. The nonlinear absorption effect of femtosecond laser could obtain the processing accuracy which is much smaller than the focal spot, meanwhile depending on this effect, microstructure superhydrophobic surfaces could be fabricated on almost all the solid materials. Although the research in the field of superhydrophobic surfaces has been conducted for over ten years, the fabricating cost and du-rability still could not meet the requirements of industrial application..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1252 (2017)
Research and development of femtosecond-laser hyperdoped silicon
Zixi Jia, Song Huang, Xiaorong Jin, Ming Yang, Zhandong Chen, Jianghong Yao, Qiang Wu, and Jingjun Xu
Silicon one of the most abundant elements in the earth's crust has a large impact on modern industry. It is an extremely versatile material with various applications ranging from solar energy to electronic devices. After decades of process, the crystalline silicon solar cell has been successfully commercialized allSilicon one of the most abundant elements in the earth's crust has a large impact on modern industry. It is an extremely versatile material with various applications ranging from solar energy to electronic devices. After decades of process, the crystalline silicon solar cell has been successfully commercialized all over the world due to its low cost and high effi-ciency. As the fundamental component of integrated circuits, silicon-based chips have shown outstanding performance in computers and cell phones. Surprisingly silicon is also a promising host material for the new generation of quantum devices owing to its excellent properties of spin. Definitely it is the core material and classical platform among various materials in the world. However, there are still some blocks which limit its applications, eg. The bandgap of crystalline silicon is only 1.12 eV (~1100 nm), which prohibited the usage in far-infrared range. The carrier mobility of silicon is not high enough, which limited performance of electronic devices..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1253 (2017)
Dual-beam super-resolution direct laser writing nanofabrication technology
Yaoyu Cao, Fei Xie, Pengda Zhang, and Xiangping Li
With the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stemWith the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stems from spatially resolved focal spot by tightly focusing laser beams. The unique 3D feature fabrication allows volumetrically integrating multiple electro- or opto-functionalities in micro/nanodevices, and thus, is promising for advancing various modern scientific technological fields such as next generation of micromechanics and opto-nanodevices. However, the feature size of structures as fabricated as well as resolution in fabrication is subject to a fundamental limit set by the diffraction na-ture of light. In this regard, the minimum feature size of structures as fabricated is commonly constrained from half the wavelength of the light output by the laser source. To improve resolution beyond the optical diffraction limit, in this review, we introduce a dual-beam super-resolution direct laser writing technique. Combined with two-photon polymeri-zation (TPP) method and stimulated emission depletion (STED) principle, the technique has successfully realized reso-lution much finer than its counterpart being obtained based on Abbe’s law, and uphold exceptional 3D nanofabrication scheme. The principle of dual-beam super-resolution laser direct writing and recent progress in improving line width and resolution have been demonstrated in the review. In general, two beams are employed in the fabrication. One beam, so called initiating beam, is used to initiate optical reactions such as photo-polymerization, and the other, namely the in-hibiting beam, is used to inhibit the optical reaction. While the initiating beam is modulated to Gaussian shape, the in-hibiting beam can be shaped into Laguerre-Gaussian mode with zero light intensity in the center. By overlapping these two beams in the focal region, the inhibiting can inhibit the fabrication in its out ring, leaving the center of the initiating beam in function. As a result, a super-resolved focal spot can be obtained with tuning the intensity ratio of the two beams. To further improve resolution to nanoscale, delicate design to the photoresin material and the focal field is re-quired. For instance, optimizing the inhibition efficiency upon the exposure to the inhibiting beam enables 9 nm free-standing line equivalent to one eighty-ninth of the wavelength of the initiating beam. Moreover, we have also summarized emerging applications of dual-beam super-resolution laser direct writing in relevant fields, such as opto-devices with photonic band gap in visible region and biology. Eventually, challenges in how to fulfill low-cost, high efficiency, large area and multi-functional materials’ fabrication and its future development are discussed..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1254 (2017)
Dual-beam super-resolution direct laser writing nanofabrication technology
Yaoyu Cao, Fei Xie, Pengda Zhang, and Xiangping Li
With the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stemWith the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stems from spatially resolved focal spot by tightly focusing laser beams. The unique 3D feature fabrication allows volumetrically integrating multiple electro- or opto-functionalities in micro/nanodevices, and thus, is promising for advancing various modern scientific technological fields such as next generation of micromechanics and opto-nanodevices. However, the feature size of structures as fabricated as well as resolution in fabrication is subject to a fundamental limit set by the diffraction na-ture of light. In this regard, the minimum feature size of structures as fabricated is commonly constrained from half the wavelength of the light output by the laser source. To improve resolution beyond the optical diffraction limit, in this review, we introduce a dual-beam super-resolution direct laser writing technique. Combined with two-photon polymeri-zation (TPP) method and stimulated emission depletion (STED) principle, the technique has successfully realized reso-lution much finer than its counterpart being obtained based on Abbe’s law, and uphold exceptional 3D nanofabrication scheme. The principle of dual-beam super-resolution laser direct writing and recent progress in improving line width and resolution have been demonstrated in the review. In general, two beams are employed in the fabrication. One beam, so called initiating beam, is used to initiate optical reactions such as photo-polymerization, and the other, namely the in-hibiting beam, is used to inhibit the optical reaction. While the initiating beam is modulated to Gaussian shape, the in-hibiting beam can be shaped into Laguerre-Gaussian mode with zero light intensity in the center. By overlapping these two beams in the focal region, the inhibiting can inhibit the fabrication in its out ring, leaving the center of the initiating beam in function. As a result, a super-resolved focal spot can be obtained with tuning the intensity ratio of the two beams. To further improve resolution to nanoscale, delicate design to the photoresin material and the focal field is re-quired. For instance, optimizing the inhibition efficiency upon the exposure to the inhibiting beam enables 9 nm free-standing line equivalent to one eighty-ninth of the wavelength of the initiating beam. Moreover, we have also summarized emerging applications of dual-beam super-resolution laser direct writing in relevant fields, such as opto-devices with photonic band gap in visible region and biology. Eventually, challenges in how to fulfill low-cost, high efficiency, large area and multi-functional materials’ fabrication and its future development are discussed..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1254 (2017)
Dual-beam super-resolution direct laser writing nanofabrication technology
Yaoyu Cao, Fei Xie, Pengda Zhang, and Xiangping Li
With the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stemWith the development of nanotechnology, emerging nanotechniques compel dramatically increasing demands on fab-rication technique for realizing nanostructures. As an important approach, direct laser writing has demonstrated ex-traordinary capabilities in fabricating three-dimensional (3D) micro/nanostructure, which stems from spatially resolved focal spot by tightly focusing laser beams. The unique 3D feature fabrication allows volumetrically integrating multiple electro- or opto-functionalities in micro/nanodevices, and thus, is promising for advancing various modern scientific technological fields such as next generation of micromechanics and opto-nanodevices. However, the feature size of structures as fabricated as well as resolution in fabrication is subject to a fundamental limit set by the diffraction na-ture of light. In this regard, the minimum feature size of structures as fabricated is commonly constrained from half the wavelength of the light output by the laser source. To improve resolution beyond the optical diffraction limit, in this review, we introduce a dual-beam super-resolution direct laser writing technique. Combined with two-photon polymeri-zation (TPP) method and stimulated emission depletion (STED) principle, the technique has successfully realized reso-lution much finer than its counterpart being obtained based on Abbe’s law, and uphold exceptional 3D nanofabrication scheme. The principle of dual-beam super-resolution laser direct writing and recent progress in improving line width and resolution have been demonstrated in the review. In general, two beams are employed in the fabrication. One beam, so called initiating beam, is used to initiate optical reactions such as photo-polymerization, and the other, namely the in-hibiting beam, is used to inhibit the optical reaction. While the initiating beam is modulated to Gaussian shape, the in-hibiting beam can be shaped into Laguerre-Gaussian mode with zero light intensity in the center. By overlapping these two beams in the focal region, the inhibiting can inhibit the fabrication in its out ring, leaving the center of the initiating beam in function. As a result, a super-resolved focal spot can be obtained with tuning the intensity ratio of the two beams. To further improve resolution to nanoscale, delicate design to the photoresin material and the focal field is re-quired. For instance, optimizing the inhibition efficiency upon the exposure to the inhibiting beam enables 9 nm free-standing line equivalent to one eighty-ninth of the wavelength of the initiating beam. Moreover, we have also summarized emerging applications of dual-beam super-resolution laser direct writing in relevant fields, such as opto-devices with photonic band gap in visible region and biology. Eventually, challenges in how to fulfill low-cost, high efficiency, large area and multi-functional materials’ fabrication and its future development are discussed..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1254 (2017)
Bioinspired hybrid wettability surface with micro/nanopatterns for efficient fog collection
[in Chinese]
In nature, it is seldom researched that the surface of many animals’ shell also reflects some specific abilities with repellency and self-cleaning micro/nanostructures.In nature, it is seldom researched that the surface of many animals’ shell also reflects some specific abilities with repellency and self-cleaning micro/nanostructures..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1255 (2017)
Laser texturing for design of superhydrophobic metal surface
[in Chinese]
The applications of metal in all fields have a very im-portant position, and it’s easy to be corroded, which lim-its its service life. Many researchers think of getting su-perhydrophobic surface with micro-nanostructure via laser processing technology.The applications of metal in all fields have a very im-portant position, and it’s easy to be corroded, which lim-its its service life. Many researchers think of getting su-perhydrophobic surface with micro-nanostructure via laser processing technology..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1255 (2017)
Laser synthesis and colloid processing
[in Chinese]
Although a large number of studies have been published on the synthesis of laser synthesis and colloidal pro-cessing insights, as well as laser nanomaterials formation mechanism and application of a large number of studies, most studies focus only on laser synthesis and colloidal processing in a certain method (such asAlthough a large number of studies have been published on the synthesis of laser synthesis and colloidal pro-cessing insights, as well as laser nanomaterials formation mechanism and application of a large number of studies, most studies focus only on laser synthesis and colloidal processing in a certain method (such as laser ablation in liquids, or laser fragmentation in liquids)..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1255 (2017)
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