Journals >Acta Photonica Sinica
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2019
Volume: 48 Issue 6
23 Article(s)
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A Soft X-ray Fluorescence Absorption Spectrometer
LI Shun, ZHAO Bin-hao, LIU Chen, WANG Jia-ou, and QIAN Hai-jie
A microchannel plate is used as a photoelectric conversion component, and a photon counting method is used as a readout method to design a practical fluorescence intensity detector. Combined with the characteristics of the 4B9B photoelectron spectroscopy experimental station of Beijing Synchrotron Radiation Facility (BA microchannel plate is used as a photoelectric conversion component, and a photon counting method is used as a readout method to design a practical fluorescence intensity detector. Combined with the characteristics of the 4B9B photoelectron spectroscopy experimental station of Beijing Synchrotron Radiation Facility (BSRF), a soft X-ray total fluorescence yield absorption spectrum detection system was developed. This detector is equipped with an independent vacuum system to facilitate docking and disassembly of the vacuum chamber of the experimental station, so that the equipment has good portability and convenience. The Ti L-edge absorption spectrum of SrTiO3 crystals with surface-coated ZnS thin films is successfully obtained by using this detection device. Compared with the total electron yield mode absorption spectra, the advantages of the detection equipment for the insulation samples and deep phase detection are demonstrated. The detector has being used in 4B9B photoelectron spectroscopy experimental station, BSRF, which extends the function of soft x-ray absorption spectrum in the study of surface catalysis, electrode materials and thin film substrates and provides a new representation method for the experimental users..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 604001 (2019)
High-precision Combined Nonuniformity Correction Method Based on Local Constant Statistics
LIU Ya-mei
To correct the nonuniformity of long-wave infrared detectors and suppress the nonlinearity and time drift, a combined nonuniformity correction method based on piece-wise two-point correction method and local constant statistics was proposed. Firstly, on the basis of the modeling of nonuniform noise, a piece-wise two-poTo correct the nonuniformity of long-wave infrared detectors and suppress the nonlinearity and time drift, a combined nonuniformity correction method based on piece-wise two-point correction method and local constant statistics was proposed. Firstly, on the basis of the modeling of nonuniform noise, a piece-wise two-point correction method is performed as a coarse correction step. Then, abnormal pixels are kicked out with the median absolute deviation method, and the mean image is calculated through multiple frames in an iterative manner. Finally, the mean image is filtered to obtain the correction matrix for the fine correction step. Two laboratory calibration experiments and one outfield experiment are performed with a principle prototype. Experimental results demonstrate that the standard deviation of the blackbody can be decreased from 2.75 to 2.26, and the roughness of the outfield scenes from 1.47×10－2 to 1.03×10－2. The proposed method has the characteristic of low complexity, strong robustness, and high precision, and is able to reduce nonuniformity noise effectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 604002 (2019)
Fabrication and Properties of Ultraviolet Detector Based on Ag-modified TiO2 Nanotubes
FANG Xiang-ming, LI Xiang, JIA Jie, SANG Dan-dan, and GAO Shi-yong
TiO2 nanotubes were synthesized on FTO substrate by liquid phase deposition method. Subsequently Ag particles were photodeposited on the surface of TiO2 nanotubes. Moreover the obtained array was investigated by SEM, EDS and XRD. As a result, TiO2 nanotubes exhite anatase phase, and there are obvious Ag particles attacTiO2 nanotubes were synthesized on FTO substrate by liquid phase deposition method. Subsequently Ag particles were photodeposited on the surface of TiO2 nanotubes. Moreover the obtained array was investigated by SEM, EDS and XRD. As a result, TiO2 nanotubes exhite anatase phase, and there are obvious Ag particles attached on the surface of the tube wall. Under UV irradiation, the ultraviolet detector based on Ag/TiO2 nanotubes shown the excellent visible-blind characteristic. After a deposition of Ag, the ultraviolet detector based on Ag/TiO2 nanotubes exhibited a high on/off ratio of 2 251, together with the photocurrent density of 91μA/cm2..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 604003 (2019)
Infrared and Low-light-level Visible Image Fusion Algorithm Based on Contrast Enhancement and Cauchy Fuzzy Function
JIANG Ze-tao, HE Yu-ting, and ZHANG Shao-qin
Due to the poor visibility of visible images in low-light environment, an image fusion algorithm based on contrast enhancement and cauchy fuzzy function is proposed to improve the fusion effect of infrared and low-light-level visible images. Firstly, the visibility of dark region of low-light-level visible image is impDue to the poor visibility of visible images in low-light environment, an image fusion algorithm based on contrast enhancement and cauchy fuzzy function is proposed to improve the fusion effect of infrared and low-light-level visible images. Firstly, the visibility of dark region of low-light-level visible image is improved by the adaptive enhancement of improved guided filtering. Secondly, non-subsampled shearlet transform is used to decompose infrared and enhanced low-light-level visible images to obtain corresponding low-frequency and high-frequency components. Then, the intuitive fuzzy sets were used to construct the cauchy membership function and adaptive dual - channel spiking cortical model to fuse the low-frequency and high-frequency components. Finally, the fusion image are reconstructed by using non-subsampled shearlet inverse transform. Experimental results show that compared with other fusion algorithms, the algorithm can effectively enhance the dark area of the low-light-level visible image and retain more background information, thus improving the contrast and clarity of the fusion image..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 610001 (2019)
Method of Aircraft Target Detection in Remote Sensing Images Based on Rotation-invariant Feature
LIN Yi, ZHAO Ming, PAN Sheng-da, and AN Bo-wen
To improve the accuracy of the multi-target detection for remote sensing image in the dynamic aircraft supervision system, a target detection method was proposed. First, two new rotation-invariance features, named center-particle angle and H-vector, are introduced. Then, the sliding detection window is used to calculatTo improve the accuracy of the multi-target detection for remote sensing image in the dynamic aircraft supervision system, a target detection method was proposed. First, two new rotation-invariance features, named center-particle angle and H-vector, are introduced. Then, the sliding detection window is used to calculate the center-particle angle and correlation coefficient of H-vector. Also, the corresponding scoring system is designed according to the matching degree of template feature to determine if there is a plane in the detection window under the assistant of non-maximum suppression. The remote sensing images of aircraft under different scenes were detected in experiment, the results show that the average F1-score reaches above 90%, and both of the recall rate and precision are higher than some traditional methods in wider scope of application..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 610002 (2019)
Asymmetric Dual Images Encryption Algorithm Based on Spectrum Fusion and Cylindrical Diffraction
ZENG Jian-qing, WANG Jun, and WU Chao
An asymmetric dual images encryption method based on optical cylindrical diffraction is proposed. Firstly, discrete cosine transform is performed on two grayscale images to obtain the corresponding spectrum. The low frequency data and the 1/3 high frequency data of the two discrete cosine transform spectra are respectiAn asymmetric dual images encryption method based on optical cylindrical diffraction is proposed. Firstly, discrete cosine transform is performed on two grayscale images to obtain the corresponding spectrum. The low frequency data and the 1/3 high frequency data of the two discrete cosine transform spectra are respectively reserved, and the low frequency and the 1/3 high frequency of one of the images are merged into a new composite spectrum, which is subjected to cylindrical diffraction and phase truncation to generate amplitude and a key for decryption. The generated amplitude is encrypted in the same way with the low-frequency data of the second image to generate a new amplitude and a key for decryption. Finally the newly generated amplitude is fused with the 1/3 high-frequency data of the second image into a new composite spectrum. The phase truncation after cylindrical diffraction produces ciphertext and a new key for decryption, where the ciphertext becomes 1/4 of the original image. Numerical simulations prove that the proposed algorithm can effectively perform dual image encryption with high key sensitivity and good robustness. Encryption tests on two images with grayscale of 512×512 show that the reconstructed images are of high quality, the correlation coefficient values are higher than 0.97, and the peak signal-to-noise ratio is greater than 33 dB. The optical image encryption based on cylindrical diffraction overcomes the symmetry of the traditional plane diffraction, and the inner cylinder radius, cylinder height and diffraction distance of the cylindrical diffraction can be used as an additional key to the encryption system, which enlarges the key space and increases system security..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 610003 (2019)
Fingerprint Anti-counterfeiting Method Based on Optical Coherence Tomography and Optical Micro-angiography
CHEN Peng, JIANG Lei, WANG Hai-xia, SUN Hao-hao, ZHANG Yi-long, and LIANG Rong-hua
A fingerprint anti-counterfeiting method was proposed. The structural information of the epidermis fingerprint, dermis fingerprint and sweat gland of the fingertip is obtained by optical coherence tomography, and the blood flow information under the fingertips of the finger is obtained by optical micro-angiography, so A fingerprint anti-counterfeiting method was proposed. The structural information of the epidermis fingerprint, dermis fingerprint and sweat gland of the fingertip is obtained by optical coherence tomography, and the blood flow information under the fingertips of the finger is obtained by optical micro-angiography, so that the fingertip biometric feature data with dynamic anti-counterfeiting is acquired. Experiments were carried out on the effectiveness of traditional commercial fingerprint scanners and proposed method using real fingerprints and fake fingerprints. The results show that the traditional commercial fingerprint collection instrument is difficult to distinguish between true and false fingerprints, and the anti-counterfeiting ability is insufficient. The fingerprint imaging of optical coherence tomography can effectively identify common artificial fingerprint products by using the obtained subcutaneous structure of the finger, and judge the true and false fingerprint based on the fingerprint state of the dermis layer; The subcutaneous blood flow imaging obtained by optical micro-angiography can be combined with the average light intensity threshold to achieve fingerprint biopsy. The accuracy of the proposed fingerprint anti-counterfeiting method can reach 100%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 611001 (2019)
Dynamic Diffuse Fluorescence Tomography System for Fluorescence Pharmacokinetics
ZHANG Li-min, LIU Han, YIN Guo-yan, LI Jiao, ZHOU Zhong-xing, and GAO Feng
To capture the fast-changing fluorescence information during a finite metabolism process in vivo, a dynamic system with the ability of parallel detection was developed based on the merits of high penetration depth and sensitivity of diffuse fluorescence tomography. It adopts the mode of muti-source and muti-detector, aTo capture the fast-changing fluorescence information during a finite metabolism process in vivo, a dynamic system with the ability of parallel detection was developed based on the merits of high penetration depth and sensitivity of diffuse fluorescence tomography. It adopts the mode of muti-source and muti-detector, and combines photo-multiplier tube detector and lock-in photon-counting technique to achieve high spatial sampling density, high sensitivity, wide dynamic range, as well as better cost-effectiveness. The assessment results show that this system has good performances in stability and ambient light suppression, and the crosstalk-rate of frequency belows 1.39%. The phantom experiment demonstrates the favorable abilities of imaging single and multiple targets. Furtherly, the in vivo experiment on indocyanine green metabolism in healthy mouse liver demonstrates the capability of capturing the fast-changing fluorescence signals in small animals for fluorescence pharmacokinetic study..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 611002 (2019)
Experimental Studies on Improved Vector Extrapolation Richardson-Lucy Algorithm Used to Realize Wave-front Coded Imaging
ZHAO Hui, XIA Jing-jing, ZHANG Ling, and FAN Xue-wu
An improved vector extrapolation based on Richardson-Lucy algorithm was designed by embedding the modified exponent into the vector extrapolation. The structural similarity index was used as a criterion to determine the optimum iterations and optimum combinations of two acceleration factors. Experimental results show tAn improved vector extrapolation based on Richardson-Lucy algorithm was designed by embedding the modified exponent into the vector extrapolation. The structural similarity index was used as a criterion to determine the optimum iterations and optimum combinations of two acceleration factors. Experimental results show that total iterations are reduced approximately 78.9% and visually satisfactory restoration results can be obtained without denoising the restored image further. This work provides a reference for the development of the Richardson-Lucy algorithm in the application of real-time wave-front coded imaging..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 611003 (2019)
Calibration Method of Micro-polarizer Array Long-wave Infrared Imaging System
YAN Yu, XU Xiao-hong, FAN Zhi-guo, ZHANG Qiang, and JIN Hai-hong
To improve the precision of micro-polarizer array long-wave infrared imaging system, for the incident light’s polarimetric information calculation problem, a polarimetric calibration method is proposed based on error analysis. By determining the relationship between the pixel level response values and the incident lighTo improve the precision of micro-polarizer array long-wave infrared imaging system, for the incident light’s polarimetric information calculation problem, a polarimetric calibration method is proposed based on error analysis. By determining the relationship between the pixel level response values and the incident light power, the generalized optical transmittance is introduced to derive and achieve the calculation of the extinction ratio and polarization orientation, further obtain the values of elements in the micro-polarizer Mueller matrix independent of large scale equations. A method to compute polarimetric information in one super pixel which contains fixed position blind pixels is proposed, contribute to getting the incident light’s polarimetric information precisely. The experiments show that this calibration method can effectively reduce error interference, and improve the detection accuray of micro-polarizer array long-wave infrared imaging system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 611004 (2019)
Development and Test of Multi-parameter Compensation Mid-infrared Methane Detector
YU Xin, LI Lei, ZHAO Jing, and WANG Yi-ding
The dual-channel non-spectroscopic infrared gas detection method is adopted, and the traditional infrared gas absorption theory is modified to develop a handheld infrared methane detector with low detection limit and high detection performance. Through the light simulation software TracePro, a variety of optical path sThe dual-channel non-spectroscopic infrared gas detection method is adopted, and the traditional infrared gas absorption theory is modified to develop a handheld infrared methane detector with low detection limit and high detection performance. Through the light simulation software TracePro, a variety of optical path structures were compared to obtain the long-path gas chamber structure in a small space to enhance the effective absorption of gas and improve the detection performance of the instrument. The multi-parameter compensation algorithm is introduced to optimize the Lambert-Beer law, and the gas absorption function adapted to the detection system is obtained to ensure the accuracy of the calculation of gas concentration information. When the instrument works, the maximum output current is 130 mA, which is powered by dry battery. The size of the instrument is 209 mm×70 mm×40 mm. The minimum detection limit is below the explosion limit of methane gas concentration reaching to 50 ppm, which can ensure the safety of the gas against explosion..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 612001 (2019)
Intercomparison of Correlated Photon Method Based on Continuous Wave and Pulsed Laser Pumping
GAO Dong-yang, LIU Chang-ming, HU You-bo, SHI Xue-shun, XIA Mao-peng, LI Jian-jun, ZHENG Xiao-bing, and WANG Heng-fei
The calibration accuracy was checked by the comparison of experimental measurements from different laboratories. To select the appropriate pumping mechanism and phase matching mode in the engineering process of correlated photon technology, the intercomparison of correlated photon method based on continuous wave and puThe calibration accuracy was checked by the comparison of experimental measurements from different laboratories. To select the appropriate pumping mechanism and phase matching mode in the engineering process of correlated photon technology, the intercomparison of correlated photon method based on continuous wave and pulsed laser pumping was carried out. The 355 nm continuous wave laser was used to pump the beta-barium borate crystal to generate correlated photon pairs. The quantum efficiency of single photon detector was measured by correcting the absorption and transmission loss in crystal and mesuring the transmission of optical elements. The calibration result of quantum efficiency based on coincidence measurement is 59.15%. Moreover, the 518 nm pulsed laser was used to pump periodically polarized potassium titanium phosphate crystal. Quasi-phase matching technique was used to get the same wavelength correlated photon. The measurement result of quantum efficiency of single photon detector is 59%. The nonuniformity of measurement results between two calibration devices is less than 0.25%. The main error sources of the intercomparison experiment result from the nonlinearity of single photon detector, the measurement error of optical elements transmission and the homogeneity of single photon detector. The advantages of the correlated photon technology which can be reproduced anytime and anywhere are verificated. In fact, the results obtained by correlated photon method is not affected by the diversity of laser pumping mechanism and phase matching modes. This conclusion has certain guiding significance for the choice of laser pumping mechanisms and phase matching modes in the engineering design process of correlated photon technology..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 612002 (2019)
Temperature Characteristics of Frequency Separation in Nd-doped Dual-frequency Microchip Laser
ZOU Yu-ling, HU Miao, LI Peng, OU Jun, ZHOU Xue-fang, YANG Guo-wei, LU Yang, and BI Mei-hua
The frequency separation temperature characteristics of Nd-doped Dual-frequency Microchip Lasers (DFMLs) were studied. The frequency separation versus the crystal temperature of DFML with different cavity lengths and different kinds of gain medium are experimented. The experimental results show that, the frequency sepaThe frequency separation temperature characteristics of Nd-doped Dual-frequency Microchip Lasers (DFMLs) were studied. The frequency separation versus the crystal temperature of DFML with different cavity lengths and different kinds of gain medium are experimented. The experimental results show that, the frequency separation is inversely proportional to the cavity length, and positively related to the crystal temperature. The frequency separation change rates with crystal temperatures of 0.5 mm, 0.8 mm and 1 mm DFML (Nd∶YVO4) are 0.34 GHz/℃, 0.12 GHz/℃ and 0.04 GHz/℃, the shorter the cavity length is, the greater frequency separation change with the crystal temperature is. The frequency separation change rate with crystal temperature of 1 mm DFML (Nd∶YVO4) and (Nd∶GdVO4) is nearly same, the simulation agrees with the experimental results well..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 614001 (2019)
Surface Incubation Effect of Carbide YG6 Induced by Femtosecond Laser
YANG Qi-biao, ZHANG Hong, ZHOU Wei, CHEN Zhong-pei, TAO Qing, and LIU Dun
A femtosecond laser with wavelength of 800 nm was used to process the micro-pits array on the surface of carbide YG6. The change of ablation threshold and ablation diameter of carbide YG6 and its ablation mechanism under different energy density and pulse number were studied by optical profiler. The result of the test A femtosecond laser with wavelength of 800 nm was used to process the micro-pits array on the surface of carbide YG6. The change of ablation threshold and ablation diameter of carbide YG6 and its ablation mechanism under different energy density and pulse number were studied by optical profiler. The result of the test shows that the multi-pulse ablation threshold of carbide YG6 decreases with the increase of the pulses number and it shows a significant accumulation effect. The quantitative relationship among ablation threshold, ablation diameter, pulses number and central energy density of multi-pulse femtosecond laser processing YG6 was obtained. The multi-pulse ablation threshold of YG6 is mainly related to the number of pulses, which is determined by ablation threshold of single pulse and accumulation coefficient. The result of the test shows that the laser ablation threshold of YG6 is 1.14±0.06 J/cm2 and accumulation coefficient is 0.84±0.02. The ablation diameter is mainly related to the energy density and the number of pulses at the center, which is determined by the beam waist radius, the ablation threshold of single pulse and the accumulation coefficient. The YG6 was ablated by multi-group average power and pulse number, which verified the reliability of the ablation threshold of single pulse and accumulation coefficient..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 614002 (2019)
Morphology Controlling of Quantum Dots Thin Films Prepared by Inkjet Printing
LEI Xiao-xiao, YE Yun, LIN Nan, CHEN En-guo, and GUO Tai-liang
Based on the microfluidic theory, the drying process of film printed with polyacrylate-QD inks was studied. Besides, the coffee ring effect was overcome by optimizing solvent ratio, polymer content and drying temperature to improve the morphology of the array films. The results showed that the addition of high boiling Based on the microfluidic theory, the drying process of film printed with polyacrylate-QD inks was studied. Besides, the coffee ring effect was overcome by optimizing solvent ratio, polymer content and drying temperature to improve the morphology of the array films. The results showed that the addition of high boiling point solvent is helpful to delay the outward flow of droplets on the substrate. Adjusting polymer content can change the physical properties of the inks, which is beneficial to induce inward flow and hinder outward flow. In addition, the polymer can ameliorate the smoothness of the films because of the leveling effect. Both of them can significantly improve the morphology of coffee ring. Moreover, adjusting drying temperature can optimize the pinning of contact line between droplet and substrate, thus further improving the morphology of coffee ring. Finally, the uniform quantum dot films and quantum dot arrays with diameters of 169 μm and heights of 65 nm were prepared at the quantum dot concentration of 12 mg/mL, the volume ratio of chlorobenzene/cyclohexyl benzene in ink is 8∶2, the mass percentage of polyacrylate is 11wt%, and the drying temperature is 25 ℃, which provides basic technical support for the fabrication of QLED devices and the full-color of Micro-LED panels..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 616001 (2019)
Influence of Electrical Injection Annealing on Property of Multi-crystalline Silicon PERC Solar Cell
PENG Jia-qi, SHEN Hong-lie, WEI Qing-zhu, NI Zhi-chun, ZHAO Lei, GU Hao, and WANG Ming-ming
Electrical injection annealing effect was performed in gallium-doped and boron-doped multi-crystalline silicon Passivated Emitter And Rear Cells (PERC). The electrical properties and the external quantum efficiency of the solar cells with different treatments were measured by the Halm electrical performance tester and Electrical injection annealing effect was performed in gallium-doped and boron-doped multi-crystalline silicon Passivated Emitter And Rear Cells (PERC). The electrical properties and the external quantum efficiency of the solar cells with different treatments were measured by the Halm electrical performance tester and quantum efficiency tester respectively.The results show that the treatment with 8.0 A electric injection current at 260 ℃ for 2 h is beneficial to promote the transition from degradation to regeneration. The conversion efficiency is enhanced by 0.83% after electric injection annealing, and the degradation of its conversion efficiency is only 0.61% from virgin value after illumination for 5 h. The light induced degradation of multi-crystalline silicon PERC colud be reduced by electrical injection annealing, and the gallium-doped multi-crystalline silicon PERC solar cell has lower light induced degradation, which is reduced by about 50% compared with that in boron-doped multi-crystalline silicon PERC solar cell..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 616002 (2019)
Preparation and Properties of Highly Flexible PVA-co-PE Nanofibers-based Composite Conductive Transparent Films
HE Xiao-wei, LIU Qiong-zhen, YI Cong, SUN Deng-ming, ZHONG Wei-bing, WANG Dong, and SUN Gang
A 3D hierarchically porous poly (vinyl alcohol)-co-poly (ethylene) nanofibrous membrane is compounded with an epoxy matrix and ultraviolet light absorbers (2,4-dihydroxybenzophenone). Owing to the strong interfacial interactions between the nanofibers and the epoxy, the obtained composite transparent substrate shows exA 3D hierarchically porous poly (vinyl alcohol)-co-poly (ethylene) nanofibrous membrane is compounded with an epoxy matrix and ultraviolet light absorbers (2,4-dihydroxybenzophenone). Owing to the strong interfacial interactions between the nanofibers and the epoxy, the obtained composite transparent substrate shows excellent flexibility, high transparency and high ultraviolet light-filtering effect. The AgNWs film and the reduced graphene oxide film are successively coated on the flexible substrate by a facile pressure transfer method to form the inter-penetrating conductive networks. The resulting composite transparent conductive film possesses a sheet resistance of 147 Ω/Sq, a visible light transmittance of 80%, and an ultraviolet light absorption over 90%. The film also exhibits excellent tensile and bending properties and maintains high electrical stability during cyclic bending tests..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 616003 (2019)
Experimental Research on Sapphire Crystal Induced by Low Energy Kr+ Ion Beam
FEI Mang-mang, CHEN Zhi-li, LIU Wei-guo, LIU Yu-zhao, and XI Ying-xue
Electron cyclotron resonance ion source has been employed to erode the surface of sapphire (crystal orientation A) and the self-organized nanostructures induced by Kr+ ion beam on sapphire surface at different incident angles are researched. The surface of the sapphire sample was etched at different incident angles usiElectron cyclotron resonance ion source has been employed to erode the surface of sapphire (crystal orientation A) and the self-organized nanostructures induced by Kr+ ion beam on sapphire surface at different incident angles are researched. The surface of the sapphire sample was etched at different incident angles using a plasma and ion beam etching equipment. The etching rate and surface morphology of the sapphire samples were analyzed by Taylor Surf CCI2000 non-contact surface measuring instrument and atomic force microscope. The experimental results indicate that, with the ion beam energy 400 eV, the accelerator voltage 200 V, and beam current density 310 μA/cm2, the ordered punctate nanostructures with small longitudinal dimension appear on the surface of the sapphire sample at small angle incidence; the increase of incident angle will obtain stripe-like nanostructure on the sample surfaces; when the incident angle continues to increase up to 30°, short-range order and stripe-like structures appear on sample surfaces with an aspect ratio of 0.87; the incident angle continues to increase and the vertical height decreases until the nanostructures disappear; when the angle reached 60°, stripe-like structures appear on sample surfaces again, and at 70°, short-range order and stripe-like structures with an aspect ratio of 1.07 are formed. The formation of self-organized nanostructures first appear in the form of "island", and then the stripe-like nanostructures are grown on the island. Eroding time extension is unable to change nanostructure topographies, but able to increase the vertical nanostructure dimensions and enhance the orderliness..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 616004 (2019)
Process Research of Wedge Mode Size Converter
WANG Xiao, SUN Tian-yu, FANG Dan, LIU Jun-cheng, TANG Ji-long, FANG Xuan, WANG Deng-kui, ZHANG Bao-shun, and WEI Zhi-peng
The stepwise principle of the step projection lithography machine is used to control the exposure dose to prepare a wedge-shaped mode size converter.The effects of different exposure doses on the sidewall morphology and the best etching parameters were analyzed. The experimental results show that the optimum exposure tThe stepwise principle of the step projection lithography machine is used to control the exposure dose to prepare a wedge-shaped mode size converter.The effects of different exposure doses on the sidewall morphology and the best etching parameters were analyzed. The experimental results show that the optimum exposure time is 20 ms each time, the reflow temperature is 160 ℃ for 1 min. When the etching gas and the ratio are SF6∶He=8∶80, the sample obtained after etching has good morphology. The preparation method has the advantages of short manufacturing cycle and high precision, and has the advantages of high efficiency and low cost compared with the electron beam gray exposure method..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 623001 (2019)
Study on Performances for White Organic Light-emitting Device Based on Color Conversion Layer
XIE Jia-feng, WANG Zhen, CHEN Ai, WANG Pei, XIAO Fei, CHEN Jia-wen, LU Yong-sheng, ZHANG Wen-xia, and WANG Yu-chan
A White Organic Light-Emitting Device(WOLED) was realized by combining dual-emission blue organic light-emitting device of ITO/NPB(30 nm)/mCP(5 nm)/mCP∶Firpic(8%, 30 nm)/TPBi∶Firpic (8%, 10 nm)/TmPyPB(30 nm)/Cs2CO3(1 nm)/Al with color conversion layer based on PMMA∶DCJTB. Experimental results indicate that the current A White Organic Light-Emitting Device(WOLED) was realized by combining dual-emission blue organic light-emitting device of ITO/NPB(30 nm)/mCP(5 nm)/mCP∶Firpic(8%, 30 nm)/TPBi∶Firpic (8%, 10 nm)/TmPyPB(30 nm)/Cs2CO3(1 nm)/Al with color conversion layer based on PMMA∶DCJTB. Experimental results indicate that the current efficiency and Color Rendering Index(CRI) can be controlled by adjusting the concentration of DCJTB in color conversion layer. The maximum current efficiency, Commission Internationale de L′Eclairage(CIE) and CRI are 13.4 cd·A－1, (0.33, 0.31) and 69, respectively, when the concentration of DCJTB is 1.0%. To further improve the device performances, TPBi/TPBi∶Ir(ppy)3 was inserted between the emission layer of TPBi∶Firpic and the electron transport layer of TmPyPB. It is illustrated that the inserted structure can improve the CRI, increase the effective absorption of color conversion layer, and limit the recombination region of excitons to enhance the optoelectronic performances of the device. The maximum current efficiency, CIE and CRI for optimal WOLED reach 17.8 cd·A－1, (0.35, 0.33) and 81, respectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 623002 (2019)
LIBS Autofocus Method Based on Acutance of Surface Image
WANG Hua-dong, FU Hong-bo, JIA Jun-wei, ZHOU Qi-qi, NI Zhi-bo, and DONG Feng-zhong
By using a homemade laser induced breakdown spectroscopy system integrated with a micro-imager, the influence of aperture, region of interest, reflectivity of sample on position sensitivity of image acutance was analyzed. The results show that image acutance is more sensitive to the position under larger aperture, largBy using a homemade laser induced breakdown spectroscopy system integrated with a micro-imager, the influence of aperture, region of interest, reflectivity of sample on position sensitivity of image acutance was analyzed. The results show that image acutance is more sensitive to the position under larger aperture, larger aperture is more suitable for the autofocus process. The reflectivity of sample has a little influence on the position sensitivity of image acutance, and the acutance of the partial image can also be used to assist the laser induced breakdown spectroscopy focus. The surface position corresponding to the maximum acutance has good repeatability for different samples and different region of interest. On this basis, an autofocus method based on the acutance of the surface image was established..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 630001 (2019)
Spectral Data Reconstruction Algorithm of Hadamard Transform Spectral Imager
LI Yun, HU Bing-liang, GAO Xiao-hui, SUN Xin, WU Deng-shan, YAN Peng, and ZHANG Xiao-rong
Based on the principle of hadamard transform spectral imager, through the mathematical modeling of its spectral imaging process, the spectral information aliasing and spatial information aliasing caused by hadamard code mask modulation are deeply analyzed, and an algorithm is proposed to remove aliasing according to thBased on the principle of hadamard transform spectral imager, through the mathematical modeling of its spectral imaging process, the spectral information aliasing and spatial information aliasing caused by hadamard code mask modulation are deeply analyzed, and an algorithm is proposed to remove aliasing according to the spectral offset.The target data is collected by the self-developed hadamard transform spectral imager. Data cube reconstruction is accomplished by the proposed algorithm of removing aliasing. Finally, the 3D data cube is restored successfully. The spatial information aliasing and spectral information aliasing are effectively removed, and the correctness of the proposed algorithm is verified..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 630002 (2019)
Discrimination of Adulterated Sesame Oil Using Fusion of Near-mid Infrared Correlation Spectra
ZHANG Jing, SHAN Hui-yong, YANG Ren-jie, JIN Hao, WU Hai-yun, and YU Ya-ping
To extract the characteristic information of complex adulterated edible oils, a method was established to distinguish adulterated sesame oil. The conventional one-dimensional near-infrared transmission spectra and mid-infrared attenuated total reflectance spectra of 40 pure and adulterated sesame oil samples were colleTo extract the characteristic information of complex adulterated edible oils, a method was established to distinguish adulterated sesame oil. The conventional one-dimensional near-infrared transmission spectra and mid-infrared attenuated total reflectance spectra of 40 pure and adulterated sesame oil samples were collected. The technology of two-trace two-dimensional correlation spectroscopy was used to obtain the synchronous and asynchronous two-dimensional near-infrared and two-dimensional mid-infrared correlation spectra of each sample. The corresponding synchronous-asynchronous two-dimensional near-infrared and two-dimensional mid-infrared correlation spectra were obtained by pretreatment. The multi-way principal component analysis was applied to extract feature information, and the score matrices were fused. The partial least squares discrimination analysis models of pure and adulterated sesame oil were established respectively using the fusion score matrix, the score matrix of synchronous-asynchronous near-infrared correlation spectra, and the score matrix of synchronous-asynchronous mid-infrared correlation spectra. The discriminant accuracies of the three models are 100%, 96.2% and 96.2% respectively. The results show that the proposed method can extract more feature information and provide better analysis results..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 48, Issue 6, 630003 (2019)
