Journals >Acta Photonica Sinica
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2018
Volume: 47 Issue 8
37 Article(s)
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Photoelectric Characteristics of Trichromatic Organic Photodetectors with Hybrid Structure
AN Tao, LIU Dan, and WU Jun-yu
By adopting solution spin coating and high-vacuum evaporation process, trichromatic organic photodetectors with planar and heterojunction hybrid device structures were prepared. The experiment was used to explore the active layer thickness, mixing degree of different components and the influence of the pre-absorption lBy adopting solution spin coating and high-vacuum evaporation process, trichromatic organic photodetectors with planar and heterojunction hybrid device structures were prepared. The experiment was used to explore the active layer thickness, mixing degree of different components and the influence of the pre-absorption layer on the photoelectric properties of the device. On this basis, sample preparation and testing of trichromatic organic photodetectors were performed. The results show that the absorption of light by the photodetector device of the hybrid structure covers almost the entire visible light region, and exhibits a broad spectrum response similar to that of the platform-type light in the range of 350~700 nm.Under the bias voltage of -1 V, the detectivity of red, green, and blue light are 2.89×1011 Jones, 3.22×1011 Jones, and 1.97×1011 Jones, respectively. It shows that the device has good detection effects on red, green and blue light, in particular, the detectivity of red light rise up 3 to 4 times..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 804001 (2018)
Large Dynamic Range Radiation Standard Transmission Research Based on Integrating Sphere Source
LIU Hui, CHEN Hong-yao, LI Jia-wei, BAO Shi-wei, YANG Bao-yun, and ZHANG Li-ming
Due to the wide spectrum range and the good performance of exit surface uniformity and angle uniformity, integrating sphere is close to the ideal Lambert uniform light source. In this paper, the principle of large dynamic range radiation standard transmission based on integrating sphere light source was proposed. That Due to the wide spectrum range and the good performance of exit surface uniformity and angle uniformity, integrating sphere is close to the ideal Lambert uniform light source. In this paper, the principle of large dynamic range radiation standard transmission based on integrating sphere light source was proposed. That is to say, under the premise of equal color temperature adjustment, a monitoring radiometer based on a linear silicon detector with a large dynamic range response, and an adjustable aperture can transfer the spectral radiance working standards of the irradiance standard lamp-solar diffuser system to a large dynamic range adjustable integral sphere light source. Thus, the dynamic range of radiation standards can be expanded. Herein, we prepared a large dynamic adjustable aperture and further discussed the spectral matching and the impact of silicon detector nonlinearity on the accuracy of radiation standard transmission. Finally, in spectrum range of 400~2 500 nm, the uncertainty of 6 orders of magnitude radiation standard is 4.3%~6.1% in integrating sphere source. It is of great significance to the quantitative development of radiometric..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 804002 (2018)
Influences of Relaxation Oscillation Noise of Pump Laseron Fiber Laser Hydrophones
HAO Ge-yang, WU Guo-jun, LIU Bo, L Pei, and WANG Hao
In phase generation carrier demodulation of fiber laser hydrophone, the physical mechanism of inherent noise near 3 kHz is analyzed theoretically and proved by an experiment. The relaxation oscillation peak of pump laser is measured firstly, and the carrier signal frequency is gradually reduced at an interval of 400 HzIn phase generation carrier demodulation of fiber laser hydrophone, the physical mechanism of inherent noise near 3 kHz is analyzed theoretically and proved by an experiment. The relaxation oscillation peak of pump laser is measured firstly, and the carrier signal frequency is gradually reduced at an interval of 400 Hz to observe the movement direction and magnitude of the inherent noise peak. The experimental results show that with the decrease of the carrier signal, the inherent noise peak moves to the low frequency direction, and the movement interval is also 400 Hz. Therefore, it is considered that carrier signal superimposed with the relaxation oscillation noise of pump laser is the cause of the inherent noise. Finally, the inherent noise is suppressed and a relatively flat background noise spectrum is obtained through reducing the carrier signal frequency of phase generation carrier demodulation algorithm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 806001 (2018)
Fiber Dispersion Measurement Based on Multi-longitudinal Mode Beat Frequency
WANG Xu, ZHANG Ling-juan, CHEN Long-fei, LI Xiao-kang, WANG Fang, and LIU Yu-fang
The dispersion measurement of optical fiber is realized by utilizing the relationship between the multi-longitudinal mode beat frequency of the laser and dispersion coefficient of resonant cavity. A narrow band and wavelength tunable reflector is used as the rear-cavity mirror of the fiber laser in the proposed system,The dispersion measurement of optical fiber is realized by utilizing the relationship between the multi-longitudinal mode beat frequency of the laser and dispersion coefficient of resonant cavity. A narrow band and wavelength tunable reflector is used as the rear-cavity mirror of the fiber laser in the proposed system, which is based on the combination of the fiber Fabery-Perot tunable filter and the optical fiber circulator. The Sagnac interferometer is used as the front-cavity mirror. The tested optical fiber is inserted in the resonator. The beat frequency of the fiber laser is measured by the spectrum analyzer, which is changed with the output wavelength of laser, and then the dispersion coefficient of the sample is obtained. The dispersion coefficient of dispersion compensation fiber and standard single mode fiber are measured respectively. The experimental results indicate that the measurement accuracy of the proposed system can meet the requirements of the communication optical fiber measurement. The proposed method has the advantages of high measurement speed, low cost, simple structure and good application prospect..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 806002 (2018)
Clock Homologus I/Q Demodulation in Phase Sensitive Optical Time-Domain Reflection System
LIU Min-han, WANG Xu, YU Miao, FU Qun-jian, CHANG Tian-ying, ZHANG Jin, and CUI Hong-liang
A phase sensitive optical time domain reflection system demodulation method based on clock homologous I/Q demodulation is proposed. The influence of the non-homologous disagreement between the modulation signal and the mixing signal on the demodulation results is analyzed. The method using clock homologous modulation sA phase sensitive optical time domain reflection system demodulation method based on clock homologous I/Q demodulation is proposed. The influence of the non-homologous disagreement between the modulation signal and the mixing signal on the demodulation results is analyzed. The method using clock homologous modulation signal of the acoustic optical modulator, the chopper signal and the I/Q mixing signal is adopted to eliminate the influence of the residual frequency. Double piezoelectric ceramic is used as the disturbance source, and the amplitude and phase of the backward Rayleigh scattering light can be obtained in real time by I/Q demodulation, so as to achieve the location and reduction of the disturbance. The experimental results show that the system can detect the sinusoidal disturbances at 5 km and 9 km effectively, and the signal to noise ratio of the positioning signal is up to 17.8 dB and 16 dB, respectively. The phase demodulation results accurately restore the sinusoidal disturbance, and the fitting coefficients of the sinusoidal curves are 0.994 and 0.991 respectively, and the root mean square error is 0.116 and 0.141, respectively. Furthermore, the experiment verifies that the method can measure the phase sine curve under different disturbance amplitudes. The different disturbance frequencies can be obtained accurately, and the phase change amplitude at disturbance location has a good linear relationship with the disturbance intensity. The linear fitting coefficient is 0.992, and the root mean square error is 0.499, both are better than the non-homologous demodulation result..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 806003 (2018)
Research and Improvement Based on PGC Demodulation Method
SUN Wei, YU Miao, CHANG Tian-ying, CHEN Jian-dong, CUI Hong-liang, and PANG Shuo
In order to obtain higher linearity and stronger anti-interference ability, an improved phase generation carrier demodulation algorithm was proposed. By using the interference signal and the base frequency mixing signal to perform the operation, the difference between the two signal times and the two signals is differeIn order to obtain higher linearity and stronger anti-interference ability, an improved phase generation carrier demodulation algorithm was proposed. By using the interference signal and the base frequency mixing signal to perform the operation, the difference between the two signal times and the two signals is differentiated and the demodulation of the detected signal is realized. The simulation results verify the feasibility and advantages of the improved demodulation algorithm, the stronger anti-interference ability and higher linearity are obtained comparing with the conventional demodulation method, and the limitations that the fundamental frequency mixer applies only to the limitations of small signal is eliminated; The experimental system is built to verify the high accuracy of frequency demodulation and the consistency of the intensity response..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 806004 (2018)
Preparation and Luminescent Properties of Phosphor Sr2La8(SiO4)6O2∶Eu(2+,3+)
WANG Fei
A series of luminescence phosphors Sr2La8(SiO4)6O2∶Eu(2+,3+)were prepared via solid-state reaction. The results of X-ray powder diffraction data analysis show that the fluorescent powder is apatite structure, belonging to the six square system, which has P63/m (176) space point group structure. The fluorescence spectraA series of luminescence phosphors Sr2La8(SiO4)6O2∶Eu(2+,3+)were prepared via solid-state reaction. The results of X-ray powder diffraction data analysis show that the fluorescent powder is apatite structure, belonging to the six square system, which has P63/m (176) space point group structure. The fluorescence spectra of the samples indicate that the excitation spectrum of Sr2La8(SiO4)6O2∶Eu (2+, 3+) is located at 200~600 nm, consisting of two broad peaks of 275 nm and 336 nm, as well as some other sharp peaks of 392 nm, 461 nm, 466 nm, 523 nm and so on. The two broadband excitation peaks can be fitted by three peaks of 272 nm, 300 nm and 336 nm, with a peak area ratio of 1: 0.52: 4.09. 272 nm and 300 nm belongs to the charge transport excited transition state of the Eu3+, and the 336 nm peak comes from the f-d transition of Eu2+. Under the excitation of 393 nm, the emission spectrum of Sr2La8(SiO4)6O2∶Eu(2+,3+) in 500 ~750 nm shows many sharp lines with the maximum peak at 613 nm, belonging to 5D0→7F1 of the electric dipole transition, and Eu3+ has occupied no inversion center of symmetry site. Eu3+ magnetic dipole transition from 5D0→7F1 peak is fitted by four peaks of 584.5 nm, 588.5 nm, 594 nm, 597 nm, showing that the Eu3+ into the host lattice occupy 4f (C3) and 6h (Cs) two case. The results of X-ray photoelectron spectroscopy analysis show that the ratio of Eu3+ and Eu2+ is close to 2∶1 in the sample. There is energy transfer between Eu2+ and Eu3+. The sample is irradiated with an ultraviolet lamp, showing a color of candlelight yellow, which has the value of application of LED..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 816001 (2018)
Ge-Ga-Se-CsI Chalcohalide with Low Zero Dispersion Wavelength
CHEN Peng, XUE Zu-gang, TIAN You-mei, ZHAO Zhe-ming, ZHANG Pei-qing, WANG Xun-si, DAI Shi-xun, WANG Rong-ping, and XU Tie-feng
The dispersion functioning mechanism of low-dispersion halides on chalcogenide glasses is studied on the influence of glass composition optimizing, refractive index adjusting and zero-dispersion wavelength shifting, with the help of Ge-Ga-Se-CsI chalcohalide glass preparation. The physical and infrared optical propertiThe dispersion functioning mechanism of low-dispersion halides on chalcogenide glasses is studied on the influence of glass composition optimizing, refractive index adjusting and zero-dispersion wavelength shifting, with the help of Ge-Ga-Se-CsI chalcohalide glass preparation. The physical and infrared optical properties of the glasses were tested by differential scanning calorimetry, infrared ellipsometer and infrared spectrometer. The purification process and glass composition to the glass formation and their optical properties were studied detailedly. The material dispersion curves of the two glass samples were calculated based on the measured data of refractive index. The experimental results show that the transmission range of the glasses is from visible to far infrared (0.55~18 μm); With the content of CsI increasing, the zero-dispersion wavelength of material decreases, in the value of 3.5 μm and 1.5 μm, corresponding to 20% CsI- and 40% CsI-chalcohalide glass, respectively. At the same time, the thermal stability of the two glasses is enough high, which is favorable for the preparation of low-dispersion mid-infrared fiber. Combined with effective glass purification method and high-temperature polymer-coating protection, a single refractive index chalcohalide glass fiber with a minimum loss of 8.2 dB/m was obtained..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 816002 (2018)
Preparation and Properties of Large Gap Ge-S-I Chalcogenide Glass
JIAO Kai, CHEN Peng, XUE Zu-gang, TIAN You-mei, SI Nian, WANG Xian-ge, ZHAO Zhe-ming, WANG Xun-si, DAI Shi-xun, and NIE Qiu-hua
In order to investigate the effects of iodine on the properties of two series of glasses with poor S-based (GeS1.5)100-xIx and (GeS2)100-xIx (x= 5,10,20,30,40), two series of glass samples were prepared by rapid vacuum and high temperature melt quenching. The density, near infrared absorption spectra, transmission specIn order to investigate the effects of iodine on the properties of two series of glasses with poor S-based (GeS1.5)100-xIx and (GeS2)100-xIx (x= 5,10,20,30,40), two series of glass samples were prepared by rapid vacuum and high temperature melt quenching. The density, near infrared absorption spectra, transmission spectra, refractive index, optical band gap and thermal expansion were measured and compared. Based on the measured refractive index data, the zero-dispersion point of the material was calculated. The results show that with the addition of iodine, the blue shift is observed in the near-infrared absorption cut-off wavelength, and the glass transition temperature and softening temperature decrease obviously. The transition temperature ranges of the two series are kept near 222~330℃ and 236~332℃, the soften temperature ranges from 267℃ to 375℃ and 282℃ to 364℃, respectively, the expansion coefficient, infrared transmittance and the optical band gap gradually increased. The actual composition of the glass was measured by scanning electron microscopy, and the loss of iodine in the glass raw material was compared with or without liquid nitrogen cooling in process of vacuuming, which shows that the impurity absorption peak intensity in the glass will be enhanced with liquid nitrogen cooling. The glass preparation and purification processes were optimized. Finally, the (GeS1.5)60I40 glass covered by high temperature polymer was drawn and its loss was measured, which is 2.8 dB/m..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 816003 (2018)
Design and Parameter Analysis of Laser Deicing Optical System
LIU Zhi-ying, MU Zhu, WANG Jia-ke, CHANG Zheng, and LIU Jin
Based on the actual requirements of laser deicing process on the spot size and the action distance, the length and transverse dimensions of the laser deicing optical system are calculated according to the process parameters of laser power and anti-laser damage threshold. Then, the adjustable focusing optical system of Based on the actual requirements of laser deicing process on the spot size and the action distance, the length and transverse dimensions of the laser deicing optical system are calculated according to the process parameters of laser power and anti-laser damage threshold. Then, the adjustable focusing optical system of high power damage with 100~500 m action distance and 200~600 mm spot size is designed. Focusing on the relationship between action distance, spot size and adjustment focusing distance, the theoretical calculation and simulation are carried out. The simulation results show that this system can achieve the desired adjustable distance and spot, which is verified by actual prototype experiments..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 822001 (2018)
Effect on Diffraction Efficiency of Diffractive Optics with Consideration of Surface Roughness
ZHAO Li-dong, CUI Qing-feng, MAO Shan, ZHAO Yuan-ming, PIAO Ming-xu, and HU Yang
Based on the expression of phase delay of the multi-layer diffractive optical elements, the mathematical model of diffraction efficiency and polychromatic integral diffraction efficiency under the influence of single-point diamond turning is proposed, and the analytical expressions are correspondingly provided. The appBased on the expression of phase delay of the multi-layer diffractive optical elements, the mathematical model of diffraction efficiency and polychromatic integral diffraction efficiency under the influence of single-point diamond turning is proposed, and the analytical expressions are correspondingly provided. The application of the multi-layer diffractive optical elements whose substrates are composed of ZnSe and ZnS for each layer is simulated and analyzed in near-infrared waveband (1.4~2.5 m). The results show that the surface roughness error leads to a decrease in the diffraction efficiency and the polychromatic integral diffraction efficiency of the multilayer diffractive optical elements, making the imaging quality of the hybrid imaging optical system decreased. Therefore, when the single-point diamond turning is used to cut optical elements, the result is instructive to draw out justified limit surface roughness error according to usage requirements..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 822002 (2018)
Optical System of Hyper-spectral Imaging Sensor with Small F Number in Broadband by Air for the Coastal Ocean Observation
SHEN Yuan, YU Lei, CHEN Jie-xiang, and XUE Hui
To solve the problems that the structure is too close to mounting the optomechanism for the engineering application, the bias slit and the thinned hemisphere lens were supplied to move enough lateral and axial air spaces between the slit, the imaging plane and the hemisphere lens. The stigmatic condition for the advancTo solve the problems that the structure is too close to mounting the optomechanism for the engineering application, the bias slit and the thinned hemisphere lens were supplied to move enough lateral and axial air spaces between the slit, the imaging plane and the hemisphere lens. The stigmatic condition for the advanced Dyson system was obtained by the geometric optical path analysis. Another two spherical lenses were introduced between the hemisphere lens and the concave grating to eliminate extra spherical aberrations and chromatic aberrations brought by the axial air spaces. The optical system of the imaging spectrometer with small F number in a broadband was designed by the advanced Dyson spectrometer and Schwarzschild two mirrors system. An example operating in 320~1 000 nm with F number 1.8 was built. The results demonstrate that aberrations are totally corrected, the modulation transfer functions of all fields of view are larger than 0.5 in the waveband, and the spectral resolution is 3.6 nm. The proposed system can be used for the coastal ocean hyper-spectrum observation..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 822003 (2018)
Ultra-compact Bandwidth-tunable Microring Resonator
DONG Wen, ZOU Yu, DU Ying, and LE Zi-chun
Based on the coupling characteristics of slot waveguides and the thermo-optical modulation, an ultra-compact microring resonator on silicon-on-insulator with the size of 15 μm×20 μm is proposed, whose bandwidth can be tuned by adjusting the heater power. The tunability characteristic is simulated through finite diBased on the coupling characteristics of slot waveguides and the thermo-optical modulation, an ultra-compact microring resonator on silicon-on-insulator with the size of 15 μm×20 μm is proposed, whose bandwidth can be tuned by adjusting the heater power. The tunability characteristic is simulated through finite difference time domain method, the result demonstrates when the wavelength of incident light is 1 550 nm, its adjustable bandwidth range is 2.5 nm at 1 900 nm wavelength for TE mode and 3.1 nm at 1 543 nm wavelength for TM mode by applying the heater power from 0 mW to 0.742 mW. The proposed device with small size, low driving power and wide tunable range of bandwidth is very promising for dynamic integrated optical signal processing such as reconfigurable filtering and routing..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 823001 (2018)
Effect of Alcohol on Air Tightness of LED Silicone Encapsulation
WEN Shang-sheng, PENG Xing, MA Bing-xu, SONG Jia-liang, FU Min, FANG Fang, HU Jie-pin, KANG Li-juan, and KONG Ling-bao
In order to explore the impact of Light Emitting Diode (LED) silicone package on the LED failure, the failure case of LED packaging glue is chosed to analyze the failure. Fourier transform infrared spectroscopy and gas chromatography mass spectrometry were used to analyze the composition of the failed samples. Finally,In order to explore the impact of Light Emitting Diode (LED) silicone package on the LED failure, the failure case of LED packaging glue is chosed to analyze the failure. Fourier transform infrared spectroscopy and gas chromatography mass spectrometry were used to analyze the composition of the failed samples. Finally, the failure mechanism of the samples was obtained based on the analysis results. The analysis results show that, the chemical incompatibility of the material in the LED lamp bead package sealing process leads to the failure of the sealing glue, and the LED lamp beads have a poor air tightness, which affects the light, electricity, heat, mechanical structure, and material properties. LED reliability is reduced; therefore, in the manufacturing process of LED, it is also necessary to avoid material incompatibility and increase the reliability of the LED..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 823002 (2018)
Tailoring the Performance of Semitransparent Organic Solar Cells by Tandem One-dimensional Photonic Crystals
LIANG Wen-yue, ZHONG Jin-yao, XU Hai-tao, DENG Hai-dong, WANG Qi-sheng, and LONG Yong-bing
Tandem One-Dimensional Photonic Crystals (1DPCs) are employed to improve the photovoltaic conversion efficiency of the semitransparent organic solar cells and tailor the see-though colors of the devices. Transfer matrix method is employed to calculate the absorption in the active layer and transmission spectra of the dTandem One-Dimensional Photonic Crystals (1DPCs) are employed to improve the photovoltaic conversion efficiency of the semitransparent organic solar cells and tailor the see-though colors of the devices. Transfer matrix method is employed to calculate the absorption in the active layer and transmission spectra of the devices. With these calculated data as inputs, the photovoltaic conversion efficiency and the see-though colors are calculated. It is revealed that an improvement of 24.4% in the photovoltaic conversion efficiency is achieved by tailoring the center wavelength of the bandgap of the top 1DPCs and bottom 1DPCs in the tandem 1DPCs. In addition, the see-through colors of the device can be tuned by tailoring the center wavelength of the bandgap of the top 1DPCs and bottom 1DPCs. Correspondingly, semitransparent organic solar cells with different see-through colors such as blue, green and red can be obtained. Compared with the single 1DPCs, tandem 1DPCs can lead to higher improvement in PCE and broader tunable range of the see-through color of the devices..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 823003 (2018)
Numerical Simulation and Experiment on Infrared Features of Exhaust Plume Based on Monte Carlo Method
ZHENG Hai-jing, BAI Ting-zhu, and WANG Quan-xi
According to the absorption characteristics of exhaust plume, a numerical model of the infrared radiation characteristics of the exhaust plume based on Monte Carlo method is set up. Then, the infrared radiation characteristics of exhaust plumes from a engine are simulated in the five infrared bands (1.32~1.69 μm, 1.56~According to the absorption characteristics of exhaust plume, a numerical model of the infrared radiation characteristics of the exhaust plume based on Monte Carlo method is set up. Then, the infrared radiation characteristics of exhaust plumes from a engine are simulated in the five infrared bands (1.32~1.69 μm, 1.56~2.27 μm, 2.27~3.8 μm, 3.8~8.3 μm and 8.3~20 μm) by this model. For verifing the rationality and reliability of the numerical simulation model, a test of the spectrum features of exhaust plume from the engine is conducted. The results suggest that there is strongest radiation of the liquid-engine exhaust plume in the band of 2.27~3.8 μm and maximum radiation area in the long-wave infrared band of 8.3~20 μm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 826001 (2018)
Goos-Hnchen and Imbert-Fedorov Displacements across the Interface of Topological Insulator and Chiral Metamaterials
TANG Long, ZENG Ran, LI Qi-liang, BI Mei-hua, YANG Guo-wei, and YANG Ya-ping
The Goos-Hnchen(GH) lateral displacement and Imbert-Fedorov(IF) transverse displacement of a linear polarized wave at the interface of topological insulator and chiral metamaterial was investigated. Based on the modified energy flux method, the expressions of the spatial shifts were derived, and the relations between The Goos-Hnchen(GH) lateral displacement and Imbert-Fedorov(IF) transverse displacement of a linear polarized wave at the interface of topological insulator and chiral metamaterial was investigated. Based on the modified energy flux method, the expressions of the spatial shifts were derived, and the relations between the shifts and the incident angle, topological magnetoelectric coupling effect, chiral parameter were also numerically discussed. It is found that, for a linear polarized TE beam, the magnetoelectric couplin effect of the topological insulator or the chirality of the chiral medium has consistent influence on both the two shifts, that is, the topological magnetoelectric coupling can generally suppress both the GH and IF shifts, and the chirality may monotonously enhance or suppress both the two shifts. When gradually enhancing the topological magnetoelectric polarizability, the GH and IF shifts of the linear polarized TM incident wave will be firstly increased, and then it will be suppressed. There exists an extreme displacement. The increase of chiral parameters makes this extreme displacement move towards the smaller value of the magnetoelectric polarizability; Although the influence of chiral parameters on the shifts is generally monotonic, but it is special in certain cases, for example, in case of the GH shift of a right-handed circularly polarized wave, during the period when the topological magnetoelectric coupling increases the shifts, the chirality will also show the enhancement, while in the stage of shift suppression by topological effect, the chirality may suppress the shifts in the meantime. The research on the GH and IF shifts at the interface of topological insulator and chiral metamaterials may develop a new way to control the GH and IF shifts. It also provides an optical method for measuring the topological magnetoelectric coupling and chiral electromagnetic cross-polarization..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 826002 (2018)
Land Integrated Navigation of Laser Doppler Velocimeter Based on Janus Configuration
WANG Qi, GAO Chun-feng, WEI Guo, ZHOU Jian, NIE Xiao-ming, and LONG Xing-wu
To suppress the influence of the vehicle jolts and the inclination variations on conventional laser Doppler velocimeters, a split-reuse laser Doppler velocimeter based on Janus configuration is designed. The velocimeter is composed of two velocimeter subsystems which are mirror-mounted and insensitive to the inclinatioTo suppress the influence of the vehicle jolts and the inclination variations on conventional laser Doppler velocimeters, a split-reuse laser Doppler velocimeter based on Janus configuration is designed. The velocimeter is composed of two velocimeter subsystems which are mirror-mounted and insensitive to the inclination variations by compensating the influence of the inclination variations on the velocity measurement. The vehicle experiment results show that the relative error of the velocimeter is 0.3% and the maximum position error of its integrated navigation is 5.8 m in a 55.6 km journey. The proposed laser Doppler velocimeter can effectively suppress the influence of the vehicle jolts and the inclination variations on velocity measurement and improve the positioning accuracy of integrated navigation systems, so it is more suitable for land integrated navigation..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 828001 (2018)
Echo Characteristics of Satellite Laser Ranging Based on Geiger Mode SPAD
LIU Yuan, AN Ning, FAN Cun-bo, WEN Guan-yu, ZHANG Hai-tao, and MA Lei
Based on the photoelectric properties of Geiger mode single photon avalanche diode, the effect of laser pulse width and echo intensity on the satellite laser ranging system range precision is analyzed, and the geodynamics satellite is observed by the satellite laser ranging system of Changchun station. The results indiBased on the photoelectric properties of Geiger mode single photon avalanche diode, the effect of laser pulse width and echo intensity on the satellite laser ranging system range precision is analyzed, and the geodynamics satellite is observed by the satellite laser ranging system of Changchun station. The results indicate that when the number of echo photon is about 1 000, the system ranging precision is about 10.2 mm, while the number of echo photon is about 8 000, the system ranging precision is about 9.4 mm, it shows that stronger echo intensity can improve the system ranging precision. When the laser pulse width is 200 ps, the precision of the system is 17.3 mm, while the pulse width is 50 ps, the system ranging precision is 10.0 mm, it indicates that the system range precision is effectively improved with the narrow pulse width. In order to further verify the theoretical conclusion, the Ajisai satellite is observed. The effect of high repetition frequency laser ranging system on the range precision is analyzed. It shows that by using the narrow pulse width and high repetition frequency system, the returns and data density per normal points are greatly increased and the range precision is also improved. Therefore, to improve the echo characteristics of satellite laser ranging system, the high quality laser with narrower laser pulse width, higher frequency and larger energy should be selected as a laser light source of satellite laser ranging system based on the Geiger mode single photon avalanche diode..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 828002 (2018)
Transport Properties of Charge Carriers in Pyrazolo-［3,4-b］-quinoline Derivative Doped Poly (N-vinylcarbazole) Film
MU Lin-ping, and HE Zhi-qun
The influence of doping of 1-phenyl-3,4-dimethyl-1H-pyrazolo-［3,4-b］-quinoline (PAQ5) on transport properties of charge carriers in Poly(N-vinylcarbazole) (PVK) polymer film was investigated in this paper. It can be seen from the macro relationships of current density J to electric field F that, when the electric fieldThe influence of doping of 1-phenyl-3,4-dimethyl-1H-pyrazolo-［3,4-b］-quinoline (PAQ5) on transport properties of charge carriers in Poly(N-vinylcarbazole) (PVK) polymer film was investigated in this paper. It can be seen from the macro relationships of current density J to electric field F that, when the electric field F is in the range of 106~ 107 V·cm-1, current density in pure PVK thin films is J∝F2.1, and in the doped PVK film with PAQ5 (4.8 wt%), J∝F2.9.The enhancement of the conductivity of the doped thin film in addition to the space charge limited current injected from the anode into PVK lay which was forming through holes transmission, there is also electronic current transported by doped particles PAQ5 which was injection from cathode. The transient photocurrent spectrums of the films measurement by Time of Flight method were analyzed. The results show that: under low electric field of 1×105~2×105 V·cm-1, the main transmission carriers in the naked PVK film are holes, and its mobility is about 7.6×10-5 cm2·V-1·s-1, while the information of electronic migration is too weak to be confirm. Carrier migration performance in the doped PVK film with 2 wt% PAQ5 is not distinct change from neked PVK film. And in the doped PVK film with 5 wt% PAQ5, the mobility of holes is about 6.0×10-5 cm2·V-1·s-1, and about 7.9×10-6 cm2·V-1·s-1 for electrons. The significant increase in electronic transport properties of doped PVK films is due to the transmission channels established by PAQ5..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 831001 (2018)
The Influence of Mg Doping Amount on the Property of Zn1-xMgxO Buffer Layer and Its Application in Cu(In,Ga)Se2 Solar Cells
WU Wen-wen, SHEN Hong-lie, CHEN Jie-yi, SHANG Hui-rong, SUN Luan-hong, GAO Kai, and LI Yu-fang
Zn1-xMgxO thin films have been prepared by sol-gel spin-coating technique instead of the CdS buffer layers synthesized by conventional chemical bath deposition for Cu(In,Ga)Se2 (CIGS) solar cells. The effects of Mg doping amount on the structural, morphological, optical properties of Zn1-xMgxO films and band alignment Zn1-xMgxO thin films have been prepared by sol-gel spin-coating technique instead of the CdS buffer layers synthesized by conventional chemical bath deposition for Cu(In,Ga)Se2 (CIGS) solar cells. The effects of Mg doping amount on the structural, morphological, optical properties of Zn1-xMgxO films and band alignment of Zn1-xMgxO/CIGS are investigated by X-ray diffraction, Atmoic force microscope, UV-vis-NIR spectroscopy and X-ray photoelectron spectroscopy. The results show that these properties changed with the increase of Mg. All the films are amorphous. The surface morphology changes from stripe to hexagon nanoparticles and the surface roughness decreases from 23.53 nm to 1.14 nm. The optical band gap increases from 3.55 eV to 3.62 eV and conduction band offsets changes from +0.68 eV to -0.33 eV. Accordingly, the band alignment of Zn1-xMgxO/CIGS changes from “spike-like” to “cliff-like”. An efficiency of up to 5.83% is achieved for a CIGS solar cell with a Zn1-xMgxO (using a molar ratio 0.1 of the Mg source and the Zn source in the precusor solution) buffer layer, which is attributed to the optimized conduction band offset of +0.22 eV at the Zn1-xMgxO/CIGS interface..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 831002 (2018)
Laser-induced Molecular Spectroscopy for Carbon with Different Element Speciation
DONG Mei-rong, LONG Jia-jian, CHEN Si-ru, WEI Li-ping, LI Wen-bing, CHEN Wei-kun, CHEN Shi-kai, YU Jian-hua, and LU Ji-dong
Organic carbon (C6H7O2) and carbonate carbon (CaCO3) with different carbon concentration were selected as the model samples to perform laser induced breakdown spectroscopy experiments. The excitation characteristics of carbon with different forms were analyzed in air atmosphere. The results showed that carbon atomic emOrganic carbon (C6H7O2) and carbonate carbon (CaCO3) with different carbon concentration were selected as the model samples to perform laser induced breakdown spectroscopy experiments. The excitation characteristics of carbon with different forms were analyzed in air atmosphere. The results showed that carbon atomic emissions could be detected from carbonate carbon, which had a good linear relationship with the carbon content. But it is difficult to detect the molecular carbon. For organic samples, not only the atomic carbon could be detected, but also can detect the molecular carbon (CN and C2), and the molecular emissions had a good correlation with carbon content. The results indicated that the formation of molecular carbon is related with the organic form. After mixing the two forms of samples, it is found that there is a good correlation between the molecular CN and the organic carbon content, which indicated that the molecular CN could be used to realize the identification of organic carbon form. On the other hand, according to the formation route of molecular CN, a certain amount of nitrogen was added to the mixed samples with two forms of carbon, performed under the Ar atmosphere, it was also found that there exist the good linear relationship between the molecular CN and the organic carbon content. All the measurements showed that either the nitrogen from the air or from the sample itself could be both used for the identification of carbon from the organic forms..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847001 (2018)
In-situ Analysis of Molten Aluminum by Laser-induced Breakdown Spectroscopy System
XIN Yong, LI Yang, LI Wei, LIU Xue, LI Jing-jing, YANG Zhi-jia, YU Hai-bin, and SUN Lan-xiang
LIBS on-line analyzer for liquid metal composition, which is designed by the LIBS project group of Shenyang Institute of automation, Chinese Academy of Sciences, is a analytical system for on-line monitoring of molten metal components in the metallurgical industry. We used this system to monitor the composition of moltLIBS on-line analyzer for liquid metal composition, which is designed by the LIBS project group of Shenyang Institute of automation, Chinese Academy of Sciences, is a analytical system for on-line monitoring of molten metal components in the metallurgical industry. We used this system to monitor the composition of molten aluminum in melting and casting plant of Liaoning Zhongwang Group Co., Ltd. After several months testing, we obtained that the optimum flow rate of argon in the probe tube is 1~1.4 L/min, and when the detection depth is located at the position where the pressure fluctuation range of argon is ±300 Pa and the pressure fluctuation is regular, the concentration of each element is stable. Finally, we calibrated our equipment by solid sampling data from laboratory analysis. The obtained results of on-line monitoring are as follows: the repeatability accuracy of Si、Fe、Cu、Mn and Cr is less than 2%; the measurement deviationis less than 0.01% for Si, Fe, Mg (concentration is between 0.1%~1%), and is less than 0.001% for Cu, Mn and Cr (concentration is less than 0.1%); the stability of the multiple rise and fall of the probe is less than 3%. On-line monitoring data meet the requirements of factory, so we can realize real time and on-line monitoring the compositions of molten aluminum..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847002 (2018)
Absolute Calibration of Laser-induced Breakdown Spectroscopy Detection System by Using a Tungsten Halogen Lamp
FEI Teng, PAN Cong-yuan, ZENG Qiang, DU Xue-wei, and WANG Qiu-ping
An absolute calibration setup for laser-induced breakdown spectroscopy detection system is built based on the radiometry theory. A tungsten halogen lamp equipped with an ultraviolet glass filter and a fused silica diffuser is used as standard light source for the calibration. Absolute calibration of a laser-induced breAn absolute calibration setup for laser-induced breakdown spectroscopy detection system is built based on the radiometry theory. A tungsten halogen lamp equipped with an ultraviolet glass filter and a fused silica diffuser is used as standard light source for the calibration. Absolute calibration of a laser-induced breakdown spectroscopy detection system with a Czerny-Turner spectrometer in the ultraviolet range is performed. The absolute spectral response of the system in the range of 310~385 nm is obtained with an uncertainty less than 7% by 2 standard deviation estimate. The absolute spectral calibration provides a way to evaluate the hardware of the laser-induced breakdown spectroscopy detection system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847003 (2018)
Effect of Moisture Content on Laser-induced Rock Cuttings Plasma Properties
JIA Jun-wei, SHE Ming-jun, FU Hong-bo, WANG Hua-dong, NI Zhi-bo, and DONG Feng-zhong
By preparing seven kinds of rock cutting samples with different moisture content, experiments were conducted to study the effect of moisture content on laser-induced rock cuttings plasma properties and the method for correcting the concentration of each element in different moisture content. The variation of the intensBy preparing seven kinds of rock cutting samples with different moisture content, experiments were conducted to study the effect of moisture content on laser-induced rock cuttings plasma properties and the method for correcting the concentration of each element in different moisture content. The variation of the intensity of the Ca 422.67 nm line with the moisture content of the rock cutting samples was studied. The average plasma temperature under different moisture contents was calculated by the Boltzmann-plot of the four lines of Ca II and Al I. The electron density of the plasma with different moisture contents was obtained by using Lorentz fitting of the Ca 422.67 nm line.The results show that with the increase of moisture content, the spectral intensity, plasma temperature, electron density all decrease linearly and there are also great differences in the quantitative analysis results of the calibration free models for each element, but the laser-induced cuttings plasma with different moisture content all meet the Mc Whirter criterion of local thermodynamic equilibrium and the calibration free model can be used for the analysis and simple correction of moisture content effects..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847004 (2018)
Quantitative Analysis of Unburned Carbon in Fly Ash by Laser-induced Breakdown Spectroscopy
HU Ruo-mu, WANG Zhen-zhen, LIU Ren-wei, ZHOU Wang-zheng, LIU Ji-ping, YAN Jun-jie, and DEGUCHI Yoshihiro
To verify the ability of LIBS to measure the change of carbon content in fly ash, in this study, 24 samples with different carbon content were obtained by mixing pulverized coal and fly ash in a certain proportion. Spectra of these samples from LIBS were studied in different delay time. The emission intensity ratio of To verify the ability of LIBS to measure the change of carbon content in fly ash, in this study, 24 samples with different carbon content were obtained by mixing pulverized coal and fly ash in a certain proportion. Spectra of these samples from LIBS were studied in different delay time. The emission intensity ratio of IMg1/IMg2 decreases with the increase of delay time. The emission intensity ratio of fly ash samples is obviously higher than that of other samples mixed with pulverized coal. The emission intensity ratio of IAl/ISi1 decreases with the increase of IMg1/IMg2. The addition of pulverized coal in the fly ash sample has a significant influence on the temperature change of plasma. By introducing the method of multivariate analysis, the ratios of spectral lines intensity of elements such as C, Al, Mg , Ca ,Fe to that of Si element were calculated as the independent variable of multivariate regression analysis, and the concentration of carbon element was taken as dependent variable, and the regression equation under different delay time was established. The results showed that the errors between the predicted values and the reference values based on the regression model were within 9%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847005 (2018)
Characteristics of Discharge Channel in Spark Discharge Assisted Laser-induced Breakdown Spectroscopy
DONG Bo, HE Xiao-yong, WANG Ya-rui, CHEN Yu-qi, and LI Run-hua
The relationship between the discharge channel and the time delay between the spark discharge and the laser pulse in spark discharge assisted laser-induced breakdown spectroscopy was investigated by using a gate-able pulsed high-voltage power source as the power supplier of the spark discharge. It was demonstrated thatThe relationship between the discharge channel and the time delay between the spark discharge and the laser pulse in spark discharge assisted laser-induced breakdown spectroscopy was investigated by using a gate-able pulsed high-voltage power source as the power supplier of the spark discharge. It was demonstrated that under suitable laser pulse energy and geometrical arrangement of the electrodes, it was possible to change the discharge channel from “V-shaped” type to parallel type by adjusting this time delay. In the “V-shaped” discharge, the spark discharge was able to increase the diameters of the craters and deteriorate the lateral resolution. However, in the parallel discharge, the spark discharge did not increase the diameters of the craters ensuring that the spatial resolution in this technique was only determined by laser-ablation. Under the condition of parallel discharge, quantitative analysis of chromium in aluminum alloy with spark discharge assisted laser-induced breakdown spectroscopy was carried out and the limit of detection of chromium reached 8.8 ppm, which was 8 times better than that obtained in LIBS without the assistance of the spark discharge. By using spark discharge under external trigger mode in the spark discharge assisted laser-induced breakdown spectroscopy, it is convenient to realize parallel discharge and surface elemental analysis of samples under high spatial resolution..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847006 (2018)
Influence of Diameter and Depth on Spatially Confined Laser-induced Silicon Plasma Spectroscopy with Cylindrical Cavity
WANG Qiu-yun, CHEN An-min, LI Su-yu, JIANG Yuan-fei, and JIN Ming-xing
The influence of depth and diameter on spatially confined laser-induced silicon plasma spectroscopy with cylindrical cavity was studied in air. 5×5 groups of cylindrical cavities were used to confine the laser-induced plasmas in current experiments, with diameters of 4, 6, 8, 10, and 12 mm. Each diameter corresponThe influence of depth and diameter on spatially confined laser-induced silicon plasma spectroscopy with cylindrical cavity was studied in air. 5×5 groups of cylindrical cavities were used to confine the laser-induced plasmas in current experiments, with diameters of 4, 6, 8, 10, and 12 mm. Each diameter corresponded to five different depths: 2, 4, 6, 8, and 10 mm, respectively. A Q-switched Nd: YAG laser with the repetition of 10 Hz and the pulse width of 10 ns was used to excite plasma inside different cylindrical cavities with various diameters and depths. Laser energy was 70 mJ. In current experimental conditions, when the diameter was 6 mm and the depth of cylindrical cavity is 2 mm, the line intensity of Si (I) 390.55 nm could obtain the maximum. Continue to increase the diameter and depth of cavity, the line intensity of Si (I) 390.55 nm decreased. We hope that this study serves as a helpful reference for future research on spatially confined LIBS..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847007 (2018)
Two-dimensional Elemental Mapping and Analysis of Natural Jade by Reheating Orthogonal Dual-pulse Laser-induced Breakdown Spectroscopy
ZHUANG Er-tian, KANG Juan, WANG Ya-rui, LI Run-hua, and CHEN Yu-qi
In order to analyze and detect the elemental distribution of natural jade sample surface, reheating orthogonal dual-pulse laser-induced breakdown spectroscopy was adopted to obtain two-dimensional (2D) surface elemental mapping of jade sample. The influence of time interval between two pulses to the signal intensities In order to analyze and detect the elemental distribution of natural jade sample surface, reheating orthogonal dual-pulse laser-induced breakdown spectroscopy was adopted to obtain two-dimensional (2D) surface elemental mapping of jade sample. The influence of time interval between two pulses to the signal intensities and signal to background ratio was studied experimentally. Variation relationship between spectral intensity and pulse energy of the reheating laser was discussed. Under optimized experimental condition, the surface scanning analysis of the natural jade within the scope of 36 mm×10 mm was implemented. With the lateral resolution of 30 microns, 2D distribution mapping of trace element iron was obtained. It was demonstrated that reheating orthogonal dual-pulse laser-induced breakdown spectroscopy technique was able to be applied to realize the detection of trace element in natural jade and improve detection sensibility which was helpful for jade identification. This surface elemental mapping technique could be used to achieve the analysis of component distribution of jade and other solid samples which will have nice application prospects..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847008 (2018)
Determination of Terrestrial and Marine Sedimentary Rocks by Laser-induced Breakdown Spectroscopy
SHE Ming-jun, FU Hong-bo, JIA Jun-wei, WANG Hua-dong, and DONG Feng-zhong
This paper mainly investigates the ability of laser-induced breakdown spectroscopy to discriminate the sedimentary facies of untreated rock samples. Twenty-seven continental and 14 marine sediment samples identified by geologists were used as samples to be analyzed. The line intensity of B, the integral intensity ratioThis paper mainly investigates the ability of laser-induced breakdown spectroscopy to discriminate the sedimentary facies of untreated rock samples. Twenty-seven continental and 14 marine sediment samples identified by geologists were used as samples to be analyzed. The line intensity of B, the integral intensity ratio of B/Ga, Sr/Ba, and Fe/Mn lines are used as the discrimination basis for discriminating the deposition phase. Because B, Ga, Sr, and Ba are very low in the rock and are not evenly distributed, a small amount of sample is difficult to distinguish. The content of Fe and Mn is relatively high, so Fe/Mn can distinguish the terrestrial and marine sediment samples well. Overall, the best distinguishing performance was exhibited with respect to other discrimination based on Fe II 259.940 nm/Mn II 259.372 nm. The results show that laser-induced breakdown spectroscopy can quickly and accurately discriminate the sedimentary facies of rock samples at the logging site..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847009 (2018)
Quantitative Analysis of Aluminium Alloy with Remote Laser-induced Breakdown Spectroscopy
ZHANG Da-cheng, FENG Zhong-qi, LI Xiao-gang, XU Li-jun, ZHAO Dong-mei, ZHU Xiao-long, and MA Xin-wen
A remote laser-induced breakdown spectroscopy device was constructed by combination a nanosecond Nd: YAG laser with a Cassegrain telescope. The distance of measurement can be up to 25 m. In addition, the quantitative analysis of micro elements, Pb, Fe and Ni, in the standard sample of aluminum alloy at different distanA remote laser-induced breakdown spectroscopy device was constructed by combination a nanosecond Nd: YAG laser with a Cassegrain telescope. The distance of measurement can be up to 25 m. In addition, the quantitative analysis of micro elements, Pb, Fe and Ni, in the standard sample of aluminum alloy at different distances is studied. The experimental results show that the correlation coefficients of the calibration curves for Pb, Fe and Ni are all higher than 0.97 at the distances from 5 to 20 meters. Though the intensity of spectral signals decreased rapidly with distance, there was not significantly different of the limits of detection with the increase of measurement distance in our experiments..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847010 (2018)
[in Chinese]
DING Yu, XIONG Xiong, and ZHAO Xing-qiang
The content of Sulfur and phosphorus in chrome steel samples were quantitatively analyzed by laser induced breakdown spectroscopy. The plasma was obtained by Nd∶YAG(1 064 nm)pulse laser in air atmosphere. The spectrum range from 200 to 800 nm was detected by Echelle spectrograph and EMCCD detector. The effects of detecThe content of Sulfur and phosphorus in chrome steel samples were quantitatively analyzed by laser induced breakdown spectroscopy. The plasma was obtained by Nd∶YAG(1 064 nm)pulse laser in air atmosphere. The spectrum range from 200 to 800 nm was detected by Echelle spectrograph and EMCCD detector. The effects of detection delay time and laser pulse energy on the spectral intensity were investigated. Under optimal conditions, sulfur and phosphorus in the three chrome steel samples were quantitatively analyzed using the internal standard method. The experimental results showed that the maximum relative standard deviation was 2.6%, and the relative errors were -8.3%~12.5%. The content of sulfur in the three chrome steel samples respectively were 0.011%, 0.0079% and 0.0048%, and phosphorus were 0.015%, 0.014% and 0.009%. LIBS technology is an effective tool for spectral analysis and expected to achieve real time, online and rapid detection for steel samples..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847011 (2018)
Magnetic Confinement Effect on Femtosecond Laser-induced Copper Plasma
XU Dong-hua, SONG Chao, ZHAO Shang-yong, GAO Xun, and LIN Jing-quan
The spectroscopy collection system of femtosecond laser-induced copper plasma with magnetic confinement was established. The magnetic confinement effects in the femtosecond laser-induced Cu plasma were investigated by optical emission spectroscopy. When plasma was confined by magnetic field with intensity of 0.67 T, thThe spectroscopy collection system of femtosecond laser-induced copper plasma with magnetic confinement was established. The magnetic confinement effects in the femtosecond laser-induced Cu plasma were investigated by optical emission spectroscopy. When plasma was confined by magnetic field with intensity of 0.67 T, the plasma emission continuous and discrete spectrum enhanced meanwhile the discrete spectrum enhanced more significantly. The enhancement factor of Cu atomic line with higher upper level energy is larger. The Cu I 507.6 nm is emitted from the highest upper level energy; its enhancement factor is largest and could be up to 2.8. The persistence duration of copper atomic spectra last longer. The copper atomic spectra enhanced significantly in the early delay time and weakly in late delay time. The electron temperature and number density of plasma in magnetic filed improved..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847012 (2018)
Effects of Hemispherical Confinement on the Enhancement of Laser-induced Glass Plasma Radiation
WANG Jing-ge, LI Xiao-long, HU Jun-tao, and LI Xin-zhong
In order to enhance the radiation spectrum signal of laser-induced glass plasma, a hemispherical cavity which was made of glass fiber with a diameter of 10 mm was used to confine the plasma. The spectrum signals with confinement and without confinement were compared. Since the focusing of the laser has a great influencIn order to enhance the radiation spectrum signal of laser-induced glass plasma, a hemispherical cavity which was made of glass fiber with a diameter of 10 mm was used to confine the plasma. The spectrum signals with confinement and without confinement were compared. Since the focusing of the laser has a great influence on the properties of the glass plasma, the focusing position of the laser in the sample was first optimized. The results show that when the sample surface is 3 mm above the focal plane of the lens, the spectral singnal from the laser-induced glass plasma was the strongest. Then the temporal evolution of spectral intensity under unconstrained and spatially constrained by a hemispherical cavity with the inner diameter of 10 mm was studied. The time evolution of the enhancement factor og the spectral intensity was analyzed. The results show that the spectral lines with confiment presents an enhanced phenomenon in the period of 6~15 μs after plasma generation. And the degree of enhancement of spectral lines with different energy levels is different. The maximum enhancement is achieved when the acquisition delay is 10 μs. Finally, the effect of laser energy on the enhancement of plasma radiation was studied. The results show that with the increase of laser energy, the enhancement factor of the spectral line is gradually increased. When the laser energy exceeds 170 mJ, the spectral enhancement effect begins to decrease..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847013 (2018)
Quantitative Analyses of Element Mn in Iron Using Portable Laser-induced Breakdown Spectroscopy with Algorithm of Background Removal Based on Wavelet Transform
ZENG Qing-dong, ZHU Zhi-heng, DENG Fan, ZHU Xiang-li, WANG Bo-yun, XIAO Yong-jun, XIONG Liang-bin, YU Hua-qing, GUO Lian-bo, and LI Xiang-you
A portable laser-induced breakdown spectroscopy system based on fiber laser was developed to meet the demand of rapid detection in industrial field and rugged environment. A algorithm of background removal based on iterative wavelet transform was used to eliminate the high continuous background interference caused by tA portable laser-induced breakdown spectroscopy system based on fiber laser was developed to meet the demand of rapid detection in industrial field and rugged environment. A algorithm of background removal based on iterative wavelet transform was used to eliminate the high continuous background interference caused by the high repetition rate of the fiber laser. The emission lines of element Mn in pig iron samples were compared before and after the background removal. After background removal by the iterative wavelet transform algorithm, the determination coefficient of calibration curve for four emission lines of element Mn was improved from 0.988, 0.985, 0.982 and 0.992, to 0.994, 0.994, 0.994 and 0.995, respectively, and the root-mean-square error of cross-validation was decrease from 0.123, 0.146, 0.101 and 0.083, to 0.072, 0.085, 0.062 and 0.073, respectively. The results show that the algorithm of iterative wavelet transform can effectively remove the continuous background interference, improve the accuracy of regression model, and then improve the accuracy of quantitative analysis..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847014 (2018)
Consensus Modeling for Qualitative Analysis of Heavy Metal Cu in Tegillarca Granosa by LIBS Approach
GUO Zhen-zhu, CHEN Xiao-jing, YUAN Lei-ming, CHEN Xi, ZHU De-hua, and YANG Shuo
In order to rapidly detect the heavy metal pollution in shellfish, the contents of heavy metal copper in tegillarca granosa were predicted by Laser-induced Breakdown Spectroscopy (LIBS) combined with the consensus strategy of mulit-models. By analysis of LIBS copper characteristic spectral lines, the characteristics ofIn order to rapidly detect the heavy metal pollution in shellfish, the contents of heavy metal copper in tegillarca granosa were predicted by Laser-induced Breakdown Spectroscopy (LIBS) combined with the consensus strategy of mulit-models. By analysis of LIBS copper characteristic spectral lines, the characteristics of copper peak intensity, area, peak ratio of copper′s peaks, were extracted, and multivariate linear regression models were developed respectively. Besides, partial least regression model was calibrated based on copper characteristic spectra region. Among the residual vectors of these calibration member models, the Lagrange multiplier method was used to optimize the linear combination between these member models, aiming at reducing the correlation between member models and minimizing the mean squared error of the consensus model. Through external validation from the prediction set, the consensus model was performed better than that of any member models, with the root mean square prediction error of 20.641 mg/kg, as well as the correlation coefficient of 0.835, and the prediction deviation was only -0.473. Results show that the LIBS technology combined with the consensus model can be used for the quantitative detection of heavy metals of aquatic products..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847015 (2018)
Lattice Boltzmann Simulation of Laser-induced Transfer of Liquid
HUANG Ya-jun, CAI Wen-lai, CHEN Ying-huai, and HUANG Zhi-gang
The mesoscopic lattice Boltzmann method and the gas-liquid two-phase flow model are used to simulate the Laser-induced Forward Transfer (LIFT) of liquid. Rayleigh-Plesset equation is introduced to calculate the evolution of the plasma bubble, so as to obtain the inlet boundary conditions for the two-phase LBM model of The mesoscopic lattice Boltzmann method and the gas-liquid two-phase flow model are used to simulate the Laser-induced Forward Transfer (LIFT) of liquid. Rayleigh-Plesset equation is introduced to calculate the evolution of the plasma bubble, so as to obtain the inlet boundary conditions for the two-phase LBM model of the LIFT. The simulation results agree well with former experimental observations. The evolution of bubble shape, the forward and backward ejections are all faithfully represented, which suggests that the dynamics of the laser-induced bubble is mainly responsible for the material transfer in LIFT. The forward liquid ejection is related to the fast expansion of the laser-induced bubble, while the backward ejection is caused by the collapse of the bubble..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 8, 847016 (2018)
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