A new design of hybrid plasmonic waveguide based on nanostructure has been proposed. Compared with the previous mixed plasmonic waveguides, the design make a vertical dielectric-slot configuration embed within the middle of the metal surface and the high-index dielectric structure. The closed structure can provide the ultra-compact mode confinement. The propagation loss due to the presence of the air slot can be greatly reduced. The design could improve the development of integrated photonic circuits.
{"title":"New design of a hybrid plasmonic waveguide","authors":"Miao Yi","doi":"10.1117/12.2181490","DOIUrl":"https://doi.org/10.1117/12.2181490","url":null,"abstract":"A new design of hybrid plasmonic waveguide based on nanostructure has been proposed. Compared with the previous mixed plasmonic waveguides, the design make a vertical dielectric-slot configuration embed within the middle of the metal surface and the high-index dielectric structure. The closed structure can provide the ultra-compact mode confinement. The propagation loss due to the presence of the air slot can be greatly reduced. The design could improve the development of integrated photonic circuits.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"68 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":"125074777","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}
Yonggang Xu, Xiaolin Zhao, Meng Lv, Guolin Yu, N. Dai, J. Chu
Magnetic metallic multilayers separated by nonmagnetic metal films are of great importance in magnetoelectronics and spintronics, due to their capacity of giving rise to giant magneto-resistance as well as the electric field control of ferromagnetism. Co/Pt multilayers are one of the typical platforms that own perpendicular magnetic anisotropy which can be tuned in various ways. Since previous investigations focus on the anomalous Hall(transverse) resistivity which characterizes the magnetization of the multilayers, much less attention has been paid to the longitudinal resistivity. In this work, we find that the longitudinal resistivity also gives rich phenomena that need further theoretical treatment. We have grown two Co/Pt multilayer structures that have different spacings between neighboring ferromagnetic layers. The one with smaller spacing shows a superparamagnetic behavior in its Hall resistivity even at a temperature as low as 1.5 K, but the longitudinal resistivity shows a well established hysteresis. The other sample shows square hysteresis in the Hall resistivity at all available temperatures up to 300 K, while the longitudinal resistivity gives no significant signals because they are mostly engulfed in the noises. The corresponding temperature dependence of the coercive field are also different. While the former gives an approximately exponential function of the temperature T, the latter can be divided to two zones, each of which can be characterized by a lnTs dependence, where s is not necessarily an integer. Such distinct features may be deeply related to the microstructures as well as the magnon scattering, which require further investigations.
{"title":"Quenching and temperature dependence of perpendicular magnetic anisotropy of Pt/Co multilayers","authors":"Yonggang Xu, Xiaolin Zhao, Meng Lv, Guolin Yu, N. Dai, J. Chu","doi":"10.1117/12.2179671","DOIUrl":"https://doi.org/10.1117/12.2179671","url":null,"abstract":"Magnetic metallic multilayers separated by nonmagnetic metal films are of great importance in magnetoelectronics and spintronics, due to their capacity of giving rise to giant magneto-resistance as well as the electric field control of ferromagnetism. Co/Pt multilayers are one of the typical platforms that own perpendicular magnetic anisotropy which can be tuned in various ways. Since previous investigations focus on the anomalous Hall(transverse) resistivity which characterizes the magnetization of the multilayers, much less attention has been paid to the longitudinal resistivity. In this work, we find that the longitudinal resistivity also gives rich phenomena that need further theoretical treatment. We have grown two Co/Pt multilayer structures that have different spacings between neighboring ferromagnetic layers. The one with smaller spacing shows a superparamagnetic behavior in its Hall resistivity even at a temperature as low as 1.5 K, but the longitudinal resistivity shows a well established hysteresis. The other sample shows square hysteresis in the Hall resistivity at all available temperatures up to 300 K, while the longitudinal resistivity gives no significant signals because they are mostly engulfed in the noises. The corresponding temperature dependence of the coercive field are also different. While the former gives an approximately exponential function of the temperature T, the latter can be divided to two zones, each of which can be characterized by a lnTs dependence, where s is not necessarily an integer. Such distinct features may be deeply related to the microstructures as well as the magnon scattering, which require further investigations.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"45 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":"126738097","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 vehicle photoelectric detection system based on guidance of machine vision is described in detail, which is composed of electric-optic turret, distributed perception module, position orientation system and data process terminal, etc. Simultaneously, a target detection method used in the system based on visual guide is also discussed in this paper. This method, based on the initial alignment of camera position and the precise alignment of target location, realizes the target acquisition and measurement by using the high-definition cameras of distributed perception module installed around the vehicle as the human eyes to guide the line of sight of optoelectronic devices on the turret to the field of view of one camera quickly and carry on small-scale target alignment operations. Simulation results show that the method could achieve the intelligent dynamic guide of photoelectric detection system, and improve the detection efficiency and accuracy.
{"title":"A vehicle photoelectric detection system based on guidance of machine vision","authors":"Yawei Wang, Yu Liu, Wei Chen, J. Chen, Jianbing Guo, Lijun Zhou, Haotian Zheng, Xuantao Zhang","doi":"10.1117/12.2179255","DOIUrl":"https://doi.org/10.1117/12.2179255","url":null,"abstract":"A vehicle photoelectric detection system based on guidance of machine vision is described in detail, which is composed of electric-optic turret, distributed perception module, position orientation system and data process terminal, etc. Simultaneously, a target detection method used in the system based on visual guide is also discussed in this paper. This method, based on the initial alignment of camera position and the precise alignment of target location, realizes the target acquisition and measurement by using the high-definition cameras of distributed perception module installed around the vehicle as the human eyes to guide the line of sight of optoelectronic devices on the turret to the field of view of one camera quickly and carry on small-scale target alignment operations. Simulation results show that the method could achieve the intelligent dynamic guide of photoelectric detection system, and improve the detection efficiency and accuracy.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"100 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":"130681197","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}
X. Liu, Mingli Li, Zhanguo Chen, G. Jia, T. Bian, Yi Li
The characteristics of photo-current-voltage and dark-current-voltage for two-photon-response semi-insulating GaAs photodetectors responding to near-infrared wavelengths of 1.31 μm and 1.55μm are investigated. The semi-insulating GaAs photodetectors were fabricated into hemisphere on whose bottom two types of electrodes were deposited. In experiments, the incident laser was adjusted to travel normally to the photodetector and focus at the center of the bottom so as to improve the nonlinear photo-responsivity markedly. It is observed that the photocurrent dependent on bias exhibits quadratic nonlinearity for both lasers and both electrode configurations, which reflects frequency-doubled absorption responsible for the physical mechanisms of the photodetectors; and the reasonable analysis demonstrates the important role of the electric-field-induced frequency-doubled absorption in two-photon response. Furthermore, it is found that the photocurrent is quite more greater when the electrode positioned at the bottom center of the photodetectors (central electrode for short) is negatively charged than that in the case of it positively charged under the conditions of the identical bias voltage and the same incident optical power; while the dark-current varies in exactly the opposite mode compared to the photocurrent. The aforementioned disparate variations of the photocurrent and the dark-current are well interpreted by the theory of surface band-bending of semi-insulating GaAs, and such variations result in a large ratio of photo-current to dark-current in the case of the central electrode negatively charged. The investigated results also indicate that the optimization of electrode structure is essential to improve the photo-responsivity of the photodetector.
{"title":"Photo-and-dark-current-voltage characteristics of normal-incidence GaAs photodetectors with two types of electrode configurations","authors":"X. Liu, Mingli Li, Zhanguo Chen, G. Jia, T. Bian, Yi Li","doi":"10.1117/12.2180320","DOIUrl":"https://doi.org/10.1117/12.2180320","url":null,"abstract":"The characteristics of photo-current-voltage and dark-current-voltage for two-photon-response semi-insulating GaAs photodetectors responding to near-infrared wavelengths of 1.31 μm and 1.55μm are investigated. The semi-insulating GaAs photodetectors were fabricated into hemisphere on whose bottom two types of electrodes were deposited. In experiments, the incident laser was adjusted to travel normally to the photodetector and focus at the center of the bottom so as to improve the nonlinear photo-responsivity markedly. It is observed that the photocurrent dependent on bias exhibits quadratic nonlinearity for both lasers and both electrode configurations, which reflects frequency-doubled absorption responsible for the physical mechanisms of the photodetectors; and the reasonable analysis demonstrates the important role of the electric-field-induced frequency-doubled absorption in two-photon response. Furthermore, it is found that the photocurrent is quite more greater when the electrode positioned at the bottom center of the photodetectors (central electrode for short) is negatively charged than that in the case of it positively charged under the conditions of the identical bias voltage and the same incident optical power; while the dark-current varies in exactly the opposite mode compared to the photocurrent. The aforementioned disparate variations of the photocurrent and the dark-current are well interpreted by the theory of surface band-bending of semi-insulating GaAs, and such variations result in a large ratio of photo-current to dark-current in the case of the central electrode negatively charged. The investigated results also indicate that the optimization of electrode structure is essential to improve the photo-responsivity of the photodetector.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"16 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":"123937179","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}
CMOS image sensors (CIS) have lower power consumption, lower cost and smaller size than CCD image sensors. However, generally CCDs have higher performance than CIS mainly due to lower noise. The pixel circuit used in CIS is the first part of the signal processing circuit and connected to photodiode directly, so its performance will greatly affect the CIS or even the whole imaging system. To achieve high performance, CMOS image sensors need advanced pixel circuits. There are many pixel circuits used in CIS, such as passive pixel sensor (PPS), 3T and 4T active pixel sensor (APS), capacitive transimpedance amplifier (CTIA), and passive pixel sensor (PPS). At first, the main performance parameters of each pixel structure including the noise, injection efficiency, sensitivity, power consumption, and stability of bias voltage are analyzed. Through the theoretical analysis of those pixel circuits, it is concluded that CTIA pixel circuit has good noise performance, high injection efficiency, stable photodiode bias, and high sensitivity with small integrator capacitor. Furthermore, the APS and CTIA pixel circuits are simulated in a standard 0.18-μm CMOS process and using a n-well/p-sub photodiode by SPICE and the simulation result confirms the theoretical analysis result. It shows the possibility that CMOS image sensors can be extended to a wide range of applications requiring high performance.
{"title":"Analysis of pixel circuits in CMOS image sensors","authors":"Zou Mei, Nan Chen, Li-bin Yao","doi":"10.1117/12.2180432","DOIUrl":"https://doi.org/10.1117/12.2180432","url":null,"abstract":"CMOS image sensors (CIS) have lower power consumption, lower cost and smaller size than CCD image sensors. However, generally CCDs have higher performance than CIS mainly due to lower noise. The pixel circuit used in CIS is the first part of the signal processing circuit and connected to photodiode directly, so its performance will greatly affect the CIS or even the whole imaging system. To achieve high performance, CMOS image sensors need advanced pixel circuits. There are many pixel circuits used in CIS, such as passive pixel sensor (PPS), 3T and 4T active pixel sensor (APS), capacitive transimpedance amplifier (CTIA), and passive pixel sensor (PPS). At first, the main performance parameters of each pixel structure including the noise, injection efficiency, sensitivity, power consumption, and stability of bias voltage are analyzed. Through the theoretical analysis of those pixel circuits, it is concluded that CTIA pixel circuit has good noise performance, high injection efficiency, stable photodiode bias, and high sensitivity with small integrator capacitor. Furthermore, the APS and CTIA pixel circuits are simulated in a standard 0.18-μm CMOS process and using a n-well/p-sub photodiode by SPICE and the simulation result confirms the theoretical analysis result. It shows the possibility that CMOS image sensors can be extended to a wide range of applications requiring high performance.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"47 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":"122856381","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}
Jiangtao Xu, Xiaojun Yang, Chang Chen, Ke Xu, Beibei Liu, Min Li, Honglin Shi
In order to solve the sensitivity’s degression in the GaAs NEA photocathode, our crew dissected the Gen. III Low-Light-Level（L-L-L）tube and analyzed the residual gas from the tub e while functionally operating via mass spectrometer. The photoemission-harmful gas like C，CO，CO2 were the principal reason cause the photocathode sensitivity to drop most. Applying the theory of dipole layer, this paper had this thorough discussion over the impact the residual pernicious gas had upon the photocathode. The residual gas on the emission layer enlarged the interface barrier and dwindled the chance of overflow about the same time.There were none photoemission when the single molecule gas were all over the emission layer, and so the life-span has came to an end as well. Our crew bring forward “carbon-contamination precaution measure” on account of lo wering potential barrier, which resolve problems like unstable photocathode sensitivity and limited life-span.
{"title":"Effect of residual gas on cathode photoelectric emission life in generation III L-L-L tube","authors":"Jiangtao Xu, Xiaojun Yang, Chang Chen, Ke Xu, Beibei Liu, Min Li, Honglin Shi","doi":"10.1117/12.2087260","DOIUrl":"https://doi.org/10.1117/12.2087260","url":null,"abstract":"In order to solve the sensitivity’s degression in the GaAs NEA photocathode, our crew dissected the Gen. III Low-Light-Level（L-L-L）tube and analyzed the residual gas from the tub e while functionally operating via mass spectrometer. The photoemission-harmful gas like C，CO，CO2 were the principal reason cause the photocathode sensitivity to drop most. Applying the theory of dipole layer, this paper had this thorough discussion over the impact the residual pernicious gas had upon the photocathode. The residual gas on the emission layer enlarged the interface barrier and dwindled the chance of overflow about the same time.There were none photoemission when the single molecule gas were all over the emission layer, and so the life-span has came to an end as well. Our crew bring forward “carbon-contamination precaution measure” on account of lo wering potential barrier, which resolve problems like unstable photocathode sensitivity and limited life-span.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"95 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":"133524885","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}
Terahertz digital holography combines the terahertz technology and digital holography technology at present, fully exploits the advantages in both of them. Unfortunately, the quality of terahertz digital holography reconstruction images is gravely harmed by speckle noise which hinders the popularization of this technology. In this paper, the maximum a posterior estimation (MAP) filter is harnessed for the restoration of the digital reconstruction images. The filtering results are compared with images filtered by Wiener Filter and conventional frequency-domain filters from both subjective and objective perspectives. As for objective assessment, we adopted speckle index (SPKI) and edge preserving index (EPI) to quantitate the quality of images. In this paper, Canny edge detector is also used to outline the target in original and reconstruction images, which then act as an important role in the evaluation of filter performance. All the analysis indicate that maximum a posterior estimation filtering algorithm performs superiorly compared with the other two competitors in this paper and has enhanced the terahertz digital holography reconstruction images to a certain degree, allowing for a more accurate boundary identification.
{"title":"Terahertz digital holography image processing based on MAP algorithm","authors":"Guang-hao Chen, Qi Li","doi":"10.1117/12.2180056","DOIUrl":"https://doi.org/10.1117/12.2180056","url":null,"abstract":"Terahertz digital holography combines the terahertz technology and digital holography technology at present, fully exploits the advantages in both of them. Unfortunately, the quality of terahertz digital holography reconstruction images is gravely harmed by speckle noise which hinders the popularization of this technology. In this paper, the maximum a posterior estimation (MAP) filter is harnessed for the restoration of the digital reconstruction images. The filtering results are compared with images filtered by Wiener Filter and conventional frequency-domain filters from both subjective and objective perspectives. As for objective assessment, we adopted speckle index (SPKI) and edge preserving index (EPI) to quantitate the quality of images. In this paper, Canny edge detector is also used to outline the target in original and reconstruction images, which then act as an important role in the evaluation of filter performance. All the analysis indicate that maximum a posterior estimation filtering algorithm performs superiorly compared with the other two competitors in this paper and has enhanced the terahertz digital holography reconstruction images to a certain degree, allowing for a more accurate boundary identification.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"44 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":"123654190","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}
Kun Huang, Yuqing He, Boyan Hou, Shan Wei, Siyuan Wang
This paper proposes an automatic targeting locating system based on dual-field imaging to improve the stability of light weapons. The system consists of a wide field of view (WFOV) camera and a narrow field of view (NFOV) camera. The WFOV camera searches the pedestrian in the scenery, the other camera tracks the pedestrian and aims it accurately. Video signal is send to the processing unit PC and control signal is send back to the imaging system. This automatic target tracking algorithm is integrated by Adaboost and Median-Flow algorithm. It is used to track the pedestrians and locate the head of the target. Experiment results show that the dual-field imaging system and proposed algorithm has robust target tracking performance.
{"title":"Automatic target locating system through cooperative dual-field imaging","authors":"Kun Huang, Yuqing He, Boyan Hou, Shan Wei, Siyuan Wang","doi":"10.1117/12.2182248","DOIUrl":"https://doi.org/10.1117/12.2182248","url":null,"abstract":"This paper proposes an automatic targeting locating system based on dual-field imaging to improve the stability of light weapons. The system consists of a wide field of view (WFOV) camera and a narrow field of view (NFOV) camera. The WFOV camera searches the pedestrian in the scenery, the other camera tracks the pedestrian and aims it accurately. Video signal is send to the processing unit PC and control signal is send back to the imaging system. This automatic target tracking algorithm is integrated by Adaboost and Median-Flow algorithm. It is used to track the pedestrians and locate the head of the target. Experiment results show that the dual-field imaging system and proposed algorithm has robust target tracking performance.","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":"116160495","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}
An integrated multi-channel receiver for a pulsed time-of-flight (TOF) laser rangefinder has been designed in this paper. The receiver chip as an important component of the laser radar device has been implemented in a 0.18um CMOS process. It consists of sixteen channels and every channel includes preamplifier, amplifier stages, high-pass filter and a timing discriminator which contains a timing comparator and a noise comparator. Each signal paths is independent of other channels. Based on the simulations, the bandwidth and transimpedance of the amplifier channel are 652MHz, 99dBΩ. Under the simulation condition of TT corner and 27℃, the propagation delay of the discriminator is 2.15ns and the propagation delay dispersion is 223ps. The power consumption during continuous measurement is 810mW, and the operating temperature range of the device is -10~60℃.
{"title":"Integrated multi-channel receiver for a pulsed time-of-flight laser radar","authors":"Yan Jiang, Ru-qing Liu, Jing-guo Zhu","doi":"10.1117/12.2178459","DOIUrl":"https://doi.org/10.1117/12.2178459","url":null,"abstract":"An integrated multi-channel receiver for a pulsed time-of-flight (TOF) laser rangefinder has been designed in this paper. The receiver chip as an important component of the laser radar device has been implemented in a 0.18um CMOS process. It consists of sixteen channels and every channel includes preamplifier, amplifier stages, high-pass filter and a timing discriminator which contains a timing comparator and a noise comparator. Each signal paths is independent of other channels. Based on the simulations, the bandwidth and transimpedance of the amplifier channel are 652MHz, 99dBΩ. Under the simulation condition of TT corner and 27℃, the propagation delay of the discriminator is 2.15ns and the propagation delay dispersion is 223ps. The power consumption during continuous measurement is 810mW, and the operating temperature range of the device is -10~60℃.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"80 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":"116455260","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}
Nowadays, traditional infrared detectors such as MCT infrared photo detectors performance nearly reached their detect theory limits. As lead to an increased interest in detectors such as QWIPs, T2SL, QCD and so on. Due to the low cost, high integration level and high performance, QWIPs is a mainstream infrared photo detector in the areas of military, medicine industries. The problem blocked the QWIPs industry development is the low quantum efficiency because of the polarization dependence of the incident light. As decided by the absorption mechanism, the QWIPs cannot absorb the normal incident infrared light. Various methods is developed to couple the normal incident light to the QWIPs. The introduction of metal gratings proved to be efficient to improve the absorption of the normal incident light which can introduce a SPPs coupling on the interface of the gratings and the QWIPs. But in the method used before usually are transmission gratings on the surface of the QWIPs devices. A kind of backscattering metal grating patterns is designed and simulated in our work to get a higher performance. It is nearly 4 times of the coupling efficiency than the transmission gratings in simulation. We also discuss some grating parameters such as grating thickness and cycle duties for their effects on the coupling efficiency and optimize these parameters to reach a highest performance. The simulation results show a new promising structure use in the QWIPs especially in the dual-band QWIPs to enhance the absorption of the long wavelength infrared light.
{"title":"Backscattering metal gratings in QWIPs to increase the long wavelength infrared light absorption","authors":"Y. Liao, Yun Xu, Guofeng Song","doi":"10.1117/12.2182255","DOIUrl":"https://doi.org/10.1117/12.2182255","url":null,"abstract":"Nowadays, traditional infrared detectors such as MCT infrared photo detectors performance nearly reached their detect theory limits. As lead to an increased interest in detectors such as QWIPs, T2SL, QCD and so on. Due to the low cost, high integration level and high performance, QWIPs is a mainstream infrared photo detector in the areas of military, medicine industries. The problem blocked the QWIPs industry development is the low quantum efficiency because of the polarization dependence of the incident light. As decided by the absorption mechanism, the QWIPs cannot absorb the normal incident infrared light. Various methods is developed to couple the normal incident light to the QWIPs. The introduction of metal gratings proved to be efficient to improve the absorption of the normal incident light which can introduce a SPPs coupling on the interface of the gratings and the QWIPs. But in the method used before usually are transmission gratings on the surface of the QWIPs devices. A kind of backscattering metal grating patterns is designed and simulated in our work to get a higher performance. It is nearly 4 times of the coupling efficiency than the transmission gratings in simulation. We also discuss some grating parameters such as grating thickness and cycle duties for their effects on the coupling efficiency and optimize these parameters to reach a highest performance. The simulation results show a new promising structure use in the QWIPs especially in the dual-band QWIPs to enhance the absorption of the long wavelength infrared light.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"78 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":"124865734","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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