Atmospheric turbulence is one of the main factors that influence the spread of laser communication in the atmosphere affect, which will change the random distribution of the refractive index of air, and affect the image quality of the beam through the atmosphere seriously. To study atmospheric turbulence in order to grasp changes in atmospheric turbulence, by taking the appropriate methods to control and reduce the effects of atmospheric turbulence on the beam quality. In addition to studying atmospheric turbulence using experimental methods and theoretical analysis. Numerical simulation is an effective means to study the problem of turbulence. Zernike polynomials were used to produce atmospheric turbulence phase screen in this article. The phase structure function and the atmospheric coherence length were used to check whether the atmospheric turbulence phase screen is right or not. Simulation results were studied show that, the atmospheric turbulence phase screen generated with Zernike polynomial method was consistent with the theoretical values in the low spatial frequency components, but, the simulation results had big difference with the theoretical values in the high spatial frequency components. The reason is that Zernike polynomials method has some limitations. In addition, the distribution of turbulence in the atmospheric turbulence phase screen can be changed by increasing the Zernike polynomials of orders or changing the receiving apertures, but which involves great and complex calculation. Therefore, in the specific application of the laser communication system, the best experimental program should be considered. Statistical properties of atmospheric turbulence phase can be described by the phase structure function. Therefore, the structure of the function will be used to determine the phase screen simulation phase screen is accurate. To give a better understanding of both methods the difference between simulation results, the simulation results of Zernike polynomials and power spectral inversion simulation results were compared. At last to give the corresponding power spectrum inversion method to simulate atmospheric turbulence phase screen simulation results and shows that the theory without making the introduction.
{"title":"On simulation and verification of the atmospheric turbulent phase screen with Zernike polynomials","authors":"Liming Dai, S. Tong, Lei Zhang, Yinhuan Wang","doi":"10.1117/12.2180218","DOIUrl":"https://doi.org/10.1117/12.2180218","url":null,"abstract":"Atmospheric turbulence is one of the main factors that influence the spread of laser communication in the atmosphere affect, which will change the random distribution of the refractive index of air, and affect the image quality of the beam through the atmosphere seriously. To study atmospheric turbulence in order to grasp changes in atmospheric turbulence, by taking the appropriate methods to control and reduce the effects of atmospheric turbulence on the beam quality. In addition to studying atmospheric turbulence using experimental methods and theoretical analysis. Numerical simulation is an effective means to study the problem of turbulence. Zernike polynomials were used to produce atmospheric turbulence phase screen in this article. The phase structure function and the atmospheric coherence length were used to check whether the atmospheric turbulence phase screen is right or not. Simulation results were studied show that, the atmospheric turbulence phase screen generated with Zernike polynomial method was consistent with the theoretical values in the low spatial frequency components, but, the simulation results had big difference with the theoretical values in the high spatial frequency components. The reason is that Zernike polynomials method has some limitations. In addition, the distribution of turbulence in the atmospheric turbulence phase screen can be changed by increasing the Zernike polynomials of orders or changing the receiving apertures, but which involves great and complex calculation. Therefore, in the specific application of the laser communication system, the best experimental program should be considered. Statistical properties of atmospheric turbulence phase can be described by the phase structure function. Therefore, the structure of the function will be used to determine the phase screen simulation phase screen is accurate. To give a better understanding of both methods the difference between simulation results, the simulation results of Zernike polynomials and power spectral inversion simulation results were compared. At last to give the corresponding power spectrum inversion method to simulate atmospheric turbulence phase screen simulation results and shows that the theory without making the introduction.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"274 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121820888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noise performance of the high speed image sensor is a bottle neck for its low illumination applications. As the foremost stage circuit, pixel noise is an important portion of high speed image sensor system. This paper has discussed and analyzed the different noise source of the 4T pixel and influence on the image quality of high speed image sensor in detail. We proposed circuit model of pixel with ideal correlated double sampler to simulate the noise source distribution in the pixel and noise reducing methods. Pixel random readout noise can be effectively reduced to 5.44e by optimizing the gate size of the reset transistor.
{"title":"Noise analysis for high speed CMOS image sensor","authors":"Zhi-qiang Guo, Liyuan Liu, Jian Liu, Nan-Jian Wu","doi":"10.1117/12.2179448","DOIUrl":"https://doi.org/10.1117/12.2179448","url":null,"abstract":"Noise performance of the high speed image sensor is a bottle neck for its low illumination applications. As the foremost stage circuit, pixel noise is an important portion of high speed image sensor system. This paper has discussed and analyzed the different noise source of the 4T pixel and influence on the image quality of high speed image sensor in detail. We proposed circuit model of pixel with ideal correlated double sampler to simulate the noise source distribution in the pixel and noise reducing methods. Pixel random readout noise can be effectively reduced to 5.44e by optimizing the gate size of the reset transistor.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121809357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongzhou Yan, Hengjing Tang, S. Deng, Gang Chen, X. Shao, Tao Li, Xue Li, H. Gong
Extended wavelength InGaAs photodiodes in 1.0~2.5μm spectral rang based on two types of material structures were investigated systematically. The first type InGaAs photodiode, marked by sample 1#, was fabricated using MOCVD epitaxial materials with P-i-N structure. The second type InGaAs photodiodes, marked by sample 2#, was fabricated using MBE epitaxial materials with P-i-N structure. The two types of photodiodes were fabricated by mesa etching technique, side-wall and surface passivation film. Dark current and voltage curves were measured by semiconductor parameters analyzer at different temperature, and dark current characteristics were analyzed using different perimeter to area method. The mechanism of the devices has been analysed. Polarization microscopy and conductive atomic force microscopy (c-AFM) have been used to investigate the local conductivity of the photodiodes’ sensitive area. Combining the optical and c-AFM micrographs with dark current characteristics, we intended to characterize the relationships of the leak current and the defect. The results indicate that sample 1# has relative much more leak defects than that of sample 2#, and thus the dark current sample 1# is higher than that of sample 2# and. The defects are generated at the body of material and spread to the surface, and these defects cause very high dark current of sample 1#.
{"title":"Study on the relationship of dark current characteristics and materials surface defects of extended wavelength InGaAs photodiodes","authors":"Hongzhou Yan, Hengjing Tang, S. Deng, Gang Chen, X. Shao, Tao Li, Xue Li, H. Gong","doi":"10.1117/12.2180244","DOIUrl":"https://doi.org/10.1117/12.2180244","url":null,"abstract":"Extended wavelength InGaAs photodiodes in 1.0~2.5μm spectral rang based on two types of material structures were investigated systematically. The first type InGaAs photodiode, marked by sample 1#, was fabricated using MOCVD epitaxial materials with P-i-N structure. The second type InGaAs photodiodes, marked by sample 2#, was fabricated using MBE epitaxial materials with P-i-N structure. The two types of photodiodes were fabricated by mesa etching technique, side-wall and surface passivation film. Dark current and voltage curves were measured by semiconductor parameters analyzer at different temperature, and dark current characteristics were analyzed using different perimeter to area method. The mechanism of the devices has been analysed. Polarization microscopy and conductive atomic force microscopy (c-AFM) have been used to investigate the local conductivity of the photodiodes’ sensitive area. Combining the optical and c-AFM micrographs with dark current characteristics, we intended to characterize the relationships of the leak current and the defect. The results indicate that sample 1# has relative much more leak defects than that of sample 2#, and thus the dark current sample 1# is higher than that of sample 2# and. The defects are generated at the body of material and spread to the surface, and these defects cause very high dark current of sample 1#.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125044383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces a method of using LED point light source as the camera calibration light. According to the characteristics of the LED point light source, the constant current source is used to provide the necessary current and the illuminometer is used to measure the luminance of the LED point light source. The constant current source is controlled by ARM MCU and exchange data with the host computer though the mode of serial communications. The PC is used as the host computer, it adjust the current according to the luminance of the LED point light source until the luminance achieve the anticipated value. By experimental analysis, we found that the LED point light source can achieve the desired requirements as the calibration light source, and the accuracy is quite better that achieve the desired effect and it can adaptive control the luminance of LED well. The system is convenient and flexible, and its performance is stable and reliable.
{"title":"High precision digital control LED spot light source used to calibrate camera","authors":"Bo-Han Du, Xiping Xu, Yang Liu","doi":"10.1117/12.2178381","DOIUrl":"https://doi.org/10.1117/12.2178381","url":null,"abstract":"This paper introduces a method of using LED point light source as the camera calibration light. According to the characteristics of the LED point light source, the constant current source is used to provide the necessary current and the illuminometer is used to measure the luminance of the LED point light source. The constant current source is controlled by ARM MCU and exchange data with the host computer though the mode of serial communications. The PC is used as the host computer, it adjust the current according to the luminance of the LED point light source until the luminance achieve the anticipated value. By experimental analysis, we found that the LED point light source can achieve the desired requirements as the calibration light source, and the accuracy is quite better that achieve the desired effect and it can adaptive control the luminance of LED well. The system is convenient and flexible, and its performance is stable and reliable.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129258053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yi Zhou, Jianxin Chen, Fangfang Wang, Zhicheng Xu, Zhizhong Bai, Chuan Jin, Li He
The barrier enhanced InAs/GaSb long wavelength photodetectors were designed and demonstrated in this paper. A PBIN detector with an electron barrier inserted between P type contactor and absorption region show significantly improved electrical performances compared to a PIN structure. The RmaxA product of the PBIN detector was measured to be 104 Ωcm2 at 80K and 7360 Ωcm2 at 50K. Temperature dependent measurements show that the tunneling currents dominate the dark current below 50K, the generation-recombination (GR) currents dominate from 50K to 90K, and the diffusion current dominate over 90K. The PBIN structure benefits from a lower electric field in the absorption region and therefore, suppressed the tunnel currents and GR currents. To improve the quantum efficiency, Be-doping was employed to convert the conductivity of the long wavelength SL structure, the PN junction moves away from the B-I hetrostructure to the π-N interface, which loses the barrier effect. Therefore, the hole barrier was needed to form a PBπBN structure. In this paper, hole barrier was designed without Al element to form a PBπBN structure. The RmaxA product of the PBπBN detector was measured to be 77 Ωcm2 and the dark current density under -0.05V bias was measured to be 8.8×10-4A/cm2 at 80K. The peak current responsivity at 9.8 μm was 2.15A/W and the quantum efficiency was 26.7%.
{"title":"High performance InAs/GaSb superlattice long wavelength photodetectors based on barrier enhanced structures","authors":"Yi Zhou, Jianxin Chen, Fangfang Wang, Zhicheng Xu, Zhizhong Bai, Chuan Jin, Li He","doi":"10.1117/12.2180425","DOIUrl":"https://doi.org/10.1117/12.2180425","url":null,"abstract":"The barrier enhanced InAs/GaSb long wavelength photodetectors were designed and demonstrated in this paper. A PBIN detector with an electron barrier inserted between P type contactor and absorption region show significantly improved electrical performances compared to a PIN structure. The RmaxA product of the PBIN detector was measured to be 104 Ωcm2 at 80K and 7360 Ωcm2 at 50K. Temperature dependent measurements show that the tunneling currents dominate the dark current below 50K, the generation-recombination (GR) currents dominate from 50K to 90K, and the diffusion current dominate over 90K. The PBIN structure benefits from a lower electric field in the absorption region and therefore, suppressed the tunnel currents and GR currents. To improve the quantum efficiency, Be-doping was employed to convert the conductivity of the long wavelength SL structure, the PN junction moves away from the B-I hetrostructure to the π-N interface, which loses the barrier effect. Therefore, the hole barrier was needed to form a PBπBN structure. In this paper, hole barrier was designed without Al element to form a PBπBN structure. The RmaxA product of the PBπBN detector was measured to be 77 Ωcm2 and the dark current density under -0.05V bias was measured to be 8.8×10-4A/cm2 at 80K. The peak current responsivity at 9.8 μm was 2.15A/W and the quantum efficiency was 26.7%.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"9522 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129593905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Wang, Yani Zhang, Xiangrong He, G. Fang, H. Gong
The noise of photoconductive detector is so weak that the PAR 124A lock-amplifier is main test facility despite of discontinuation by long-gone manufacturer for decades. The paper uses 124A and 7124 lock-in amplifier system to test noise and response signal of several photoconductive detectors while use the SR830 internal oscillator and thermal noise of pure resistance as standard signal and noise source respectively. The results indicate that the data of two test system can fit each other except the background noise. The 124A lock-in amplifier with 116 transformer is 0.2nV/√Hz and 7124 lock-in amplifier with 5184 preamplifier is 0.8 nV/√Hz at 1kHz. The impedance of 116 transformer is small and the impedance of 5184 preamplifier is 5MΩ, so the signal of 116 transformer will decay and the 5184 preamplifier won’t in case of testing the performance of photoconductive detector with larger source resistance. Finally we suggest to use 7124 lock-in amplifier system in case of testing photoconductive detector with larger source resistance and use 124A lock-in amplifier system prior to 7124 lock-in amplifier system in case of testing photoconductive detector with small source resistance.
{"title":"The signal detection technology of photoconductive detector with lock-in amplifier","authors":"Yang Wang, Yani Zhang, Xiangrong He, G. Fang, H. Gong","doi":"10.1117/12.2178638","DOIUrl":"https://doi.org/10.1117/12.2178638","url":null,"abstract":"The noise of photoconductive detector is so weak that the PAR 124A lock-amplifier is main test facility despite of discontinuation by long-gone manufacturer for decades. The paper uses 124A and 7124 lock-in amplifier system to test noise and response signal of several photoconductive detectors while use the SR830 internal oscillator and thermal noise of pure resistance as standard signal and noise source respectively. The results indicate that the data of two test system can fit each other except the background noise. The 124A lock-in amplifier with 116 transformer is 0.2nV/√Hz and 7124 lock-in amplifier with 5184 preamplifier is 0.8 nV/√Hz at 1kHz. The impedance of 116 transformer is small and the impedance of 5184 preamplifier is 5MΩ, so the signal of 116 transformer will decay and the 5184 preamplifier won’t in case of testing the performance of photoconductive detector with larger source resistance. Finally we suggest to use 7124 lock-in amplifier system in case of testing photoconductive detector with larger source resistance and use 124A lock-in amplifier system prior to 7124 lock-in amplifier system in case of testing photoconductive detector with small source resistance.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124247030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inspired to in order to reveal the structure to improve imaging resolution, further technical requirement is proposed in some areas of the function and influence on the development of multiple configuration. To breakthrough diffraction limit, smart structures are recommended as the most efficient and economical method, while by used to improve the system performance, especially on signal to noise ratio and resolution. Integrated optics were considered in the selection, with which typical multiple configuration, by use the method of simulation experiment. Methodology can change traditional design concept and to develop the application space. Our calculations using multiple matrix transfer method, also the correlative algorithm and full calculations, show the expected beam shaping through system and, in particular, the experimental results will support our argument, which will be reported in the presentation.
{"title":"Integrated optics to improve resolution on multiple configuration","authors":"Hua Liu, Q. Ding, Chunjie Guo, Li-wei Zhou","doi":"10.1117/12.2182937","DOIUrl":"https://doi.org/10.1117/12.2182937","url":null,"abstract":"Inspired to in order to reveal the structure to improve imaging resolution, further technical requirement is proposed in some areas of the function and influence on the development of multiple configuration. To breakthrough diffraction limit, smart structures are recommended as the most efficient and economical method, while by used to improve the system performance, especially on signal to noise ratio and resolution. Integrated optics were considered in the selection, with which typical multiple configuration, by use the method of simulation experiment. Methodology can change traditional design concept and to develop the application space. Our calculations using multiple matrix transfer method, also the correlative algorithm and full calculations, show the expected beam shaping through system and, in particular, the experimental results will support our argument, which will be reported in the presentation.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123484587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration of fluorescence lifetimes. A fluorescence lifetime map was used to model the virtual scene being photographed. In order to guide the design of FLIM SPAD image sensors, the impacts of some parameters of FLIM SPAD image sensors, such as DCR and timing jitter, were analyzed by the proposed model. The impacts of the above parameters on sensors quantified by the simulation results indicated that the FLIM SPAD image sensor can get a better performance with smaller DCR and shorter timing jitter.
{"title":"Modeling and simulation of time-gated FLIM SPAD image sensors","authors":"Xinlei Wang, Kaiming Nie, Jun Qiao, Jiangtao Xu","doi":"10.1117/12.2182158","DOIUrl":"https://doi.org/10.1117/12.2182158","url":null,"abstract":"A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration of fluorescence lifetimes. A fluorescence lifetime map was used to model the virtual scene being photographed. In order to guide the design of FLIM SPAD image sensors, the impacts of some parameters of FLIM SPAD image sensors, such as DCR and timing jitter, were analyzed by the proposed model. The impacts of the above parameters on sensors quantified by the simulation results indicated that the FLIM SPAD image sensor can get a better performance with smaller DCR and shorter timing jitter.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127670001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A particular system for excess noise of avalanche photodiode (APD) measurement was build. Then the signal-noise ratio at different reverse voltage and the noise spectrum are measured and analyzed on different devices. First, the noise measurement system was constructed to fulfill the requirement that a high DC voltage can be applied on, and the measurement system was carefully shielded to protect from disturbance of electromagnetic radiations. Than we measured the noise spectrums of separate absorption and multiplication (SAM) type solar-blind APDs. The noise spectrums of SAM APDs which have different dark current levels were also measured. The results show that the low-frequency noise is dominant across a wide frequency range. And as the dark current goes higher, shot noise and low-frequency noise go higher at the same time. And the low-frequency noise will also takes more proportion in the spectrum when dark current goes higher. On the other hand, noise measurements at different reverse voltage and in either UV illumination or dark show that the excess noise factor increase faster as the gain increase. This leads to a decrease of signal-noise ratio at very high gain. In order to get a higher signal-noise ratio, a proper high gain should be adopted, rather than a gain “higher and better”.
{"title":"Noise characteristic of AlGaN-based solar-blind UV avalanche photodiodes","authors":"C. Chang, J. T. Xu, X. Y. Li","doi":"10.1117/12.2180427","DOIUrl":"https://doi.org/10.1117/12.2180427","url":null,"abstract":"A particular system for excess noise of avalanche photodiode (APD) measurement was build. Then the signal-noise ratio at different reverse voltage and the noise spectrum are measured and analyzed on different devices. First, the noise measurement system was constructed to fulfill the requirement that a high DC voltage can be applied on, and the measurement system was carefully shielded to protect from disturbance of electromagnetic radiations. Than we measured the noise spectrums of separate absorption and multiplication (SAM) type solar-blind APDs. The noise spectrums of SAM APDs which have different dark current levels were also measured. The results show that the low-frequency noise is dominant across a wide frequency range. And as the dark current goes higher, shot noise and low-frequency noise go higher at the same time. And the low-frequency noise will also takes more proportion in the spectrum when dark current goes higher. On the other hand, noise measurements at different reverse voltage and in either UV illumination or dark show that the excess noise factor increase faster as the gain increase. This leads to a decrease of signal-noise ratio at very high gain. In order to get a higher signal-noise ratio, a proper high gain should be adopted, rather than a gain “higher and better”.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121453277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to study the influence of environment temperature variation on the quality of holographic images, the change of transmit path in the holographic optical system is analyzed for both objective beam and reference beam before and after mirror deformation. In theory, finite element analysis method is used to simulate the anti-three through seven mirror deformation at 27℃, 28℃ and 29℃. And a new real-time monitoring and displaying laser speckle system is designed for measuring ambient temperature and beam splitting mirror distortion detection. The deformation value measured in the experiment are 406nm, 420nm and 427nm respectively at the same temperature mentioned above. The results show that theoretical and experimental values are in good agreement, and errors are less than 0.5%.
{"title":"Research on micro-deformation of beam splitting mirror in holographic system by laser speckle method","authors":"Xiuyan Chen, Delong Yang","doi":"10.1117/12.2180694","DOIUrl":"https://doi.org/10.1117/12.2180694","url":null,"abstract":"In order to study the influence of environment temperature variation on the quality of holographic images, the change of transmit path in the holographic optical system is analyzed for both objective beam and reference beam before and after mirror deformation. In theory, finite element analysis method is used to simulate the anti-three through seven mirror deformation at 27℃, 28℃ and 29℃. And a new real-time monitoring and displaying laser speckle system is designed for measuring ambient temperature and beam splitting mirror distortion detection. The deformation value measured in the experiment are 406nm, 420nm and 427nm respectively at the same temperature mentioned above. The results show that theoretical and experimental values are in good agreement, and errors are less than 0.5%.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115915159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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