N. Baier, L. Mollard, O. Gravrand, G. Bourgeois, J. Zanatta, G. Destefanis, O. Boulade, V. Moreau, F. Pinsard, L. Tauziède, A. Bardoux, L. Rubaldo, A. Kerlain, J. Peyrard
In this paper, we report on results obtained both at CEA/LETI and SOFRADIR on p-on-n HgCdTe (MCT) grown by liquid phase epitaxy (LPE) Infra-Red Focal Plane Arrays (IR FPAs) for the Long-wave (LW) and the Very-long-wave (VLW) spectral ranges. For many years, p-on-n arsenic-ion implanted planar technology has been developed and improved within the framework of the joint laboratory DEFIR. Compared to n-on-p, p-on-n technology presents lower dark current and series resistance. Consequently, p-on-n photodiodes are well-adapted for very large FPAs operating either at high temperature or very low flux. The long wave (LW) spectral ranges have been firstly addressed with TV/4, 30 µm pitch FPAs. Our results showed state-of-the-art detector performances, consistent with "Rule 07" law [1], a relevant indicator of the maturity of photodiode technology. The low dark current allows increasing the operating temperature without any degradation of the performances. The subsequent development of p-on-n imagers has produced more compact, less energy consuming systems, with a substantial resolution enhancement. Space applications are another exciting but challenging domains and are good candidates for the p-on-n technology. For this purpose, TV/4 arrays, 30 µm pixel pitch, have been manufactured for the very long wave spectral range. For this detection range, the quality of material and reliability of technology are the most critical. Detectors with different cutoff wavelength have been manufactured to aim 12.5 µm at 78K, 12.5 µm at 40K and 15 µm at 78K. Electro-optical characterizations reveal homogeneous imagers with excellent current operabilities (over 99.9% at best). The results highlight the very good quality of p-on-n technology with carrier diffusion limited dark current, fitting the "Rule 07" law, and high quantum efficiency. Further process developments have been made to improve photodiodes performances. Especially the transition temperature where the dark current shifts from diffusion limited regime to another one, has been lowered by more than 10K. Extremely low dark current has been obtained, down to 50 e-/s/pixel.
{"title":"MCT planar p-on-n LW and VLW IRFPAs","authors":"N. Baier, L. Mollard, O. Gravrand, G. Bourgeois, J. Zanatta, G. Destefanis, O. Boulade, V. Moreau, F. Pinsard, L. Tauziède, A. Bardoux, L. Rubaldo, A. Kerlain, J. Peyrard","doi":"10.1117/12.2016369","DOIUrl":"https://doi.org/10.1117/12.2016369","url":null,"abstract":"In this paper, we report on results obtained both at CEA/LETI and SOFRADIR on p-on-n HgCdTe (MCT) grown by liquid phase epitaxy (LPE) Infra-Red Focal Plane Arrays (IR FPAs) for the Long-wave (LW) and the Very-long-wave (VLW) spectral ranges. For many years, p-on-n arsenic-ion implanted planar technology has been developed and improved within the framework of the joint laboratory DEFIR. Compared to n-on-p, p-on-n technology presents lower dark current and series resistance. Consequently, p-on-n photodiodes are well-adapted for very large FPAs operating either at high temperature or very low flux. The long wave (LW) spectral ranges have been firstly addressed with TV/4, 30 µm pitch FPAs. Our results showed state-of-the-art detector performances, consistent with \"Rule 07\" law [1], a relevant indicator of the maturity of photodiode technology. The low dark current allows increasing the operating temperature without any degradation of the performances. The subsequent development of p-on-n imagers has produced more compact, less energy consuming systems, with a substantial resolution enhancement. Space applications are another exciting but challenging domains and are good candidates for the p-on-n technology. For this purpose, TV/4 arrays, 30 µm pixel pitch, have been manufactured for the very long wave spectral range. For this detection range, the quality of material and reliability of technology are the most critical. Detectors with different cutoff wavelength have been manufactured to aim 12.5 µm at 78K, 12.5 µm at 40K and 15 µm at 78K. Electro-optical characterizations reveal homogeneous imagers with excellent current operabilities (over 99.9% at best). The results highlight the very good quality of p-on-n technology with carrier diffusion limited dark current, fitting the \"Rule 07\" law, and high quantum efficiency. Further process developments have been made to improve photodiodes performances. Especially the transition temperature where the dark current shifts from diffusion limited regime to another one, has been lowered by more than 10K. Extremely low dark current has been obtained, down to 50 e-/s/pixel.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125892936","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. Sood, Robert A. Richwine, G. Pethuraja, Y. Puri, Jesuk Lee, P. Haldar, N. Dhar
Low cost IR Sensors are needed for a variety of Defense and Commercial Applications as low cost imagers for various Army and Marine missions. SiGe based IR Focal Planes offers a low cost alternative for developing wafer-level shortwave infrared micro-camera that will not require any cooling and can operate in the Visible-NIR band. The attractive features of SiGe based IRFPA’s will take advantage of Silicon based technology, that promises small feature size and compatibility with the low power silicon CMOS circuits for signal processing. SiGe technology offers a low cost alternative for developing Visible-NIR sensors that will not require any cooling and can operate from 0.4- 1.7 microns. The attractive features of SiGe based IRFPA’s will take advantage of Silicon based technology that can be processed on 12-inch silicon substrates, that can promise small feature size and compatibility with the Silicon CMOS circuit for signal processing. In this paper, we will discuss the design and development of Wafer-Level Short Wave Infrared (SWIR) Micro-Camera. We will discuss manufacturing approaches and sensor configurations for short wave infrared (SWIR) focal plane arrays (FPAs) that significantly reduce the cost of SWIR FPA packaging, optics and integration into micro-systems.
{"title":"Design and development of wafer-level short wave infrared micro-camera","authors":"A. Sood, Robert A. Richwine, G. Pethuraja, Y. Puri, Jesuk Lee, P. Haldar, N. Dhar","doi":"10.1117/12.1518471","DOIUrl":"https://doi.org/10.1117/12.1518471","url":null,"abstract":"Low cost IR Sensors are needed for a variety of Defense and Commercial Applications as low cost imagers for various Army and Marine missions. SiGe based IR Focal Planes offers a low cost alternative for developing wafer-level shortwave infrared micro-camera that will not require any cooling and can operate in the Visible-NIR band. The attractive features of SiGe based IRFPA’s will take advantage of Silicon based technology, that promises small feature size and compatibility with the low power silicon CMOS circuits for signal processing. SiGe technology offers a low cost alternative for developing Visible-NIR sensors that will not require any cooling and can operate from 0.4- 1.7 microns. The attractive features of SiGe based IRFPA’s will take advantage of Silicon based technology that can be processed on 12-inch silicon substrates, that can promise small feature size and compatibility with the Silicon CMOS circuit for signal processing. In this paper, we will discuss the design and development of Wafer-Level Short Wave Infrared (SWIR) Micro-Camera. We will discuss manufacturing approaches and sensor configurations for short wave infrared (SWIR) focal plane arrays (FPAs) that significantly reduce the cost of SWIR FPA packaging, optics and integration into micro-systems.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"41 23","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113993399","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}
Design of a 90×8 CMOS readout integrated circuit (ROIC) based on pixel level digital time delay integration (TDI) for scanning type LWIR focal plane arrays (FPAs) is presented. TDI is implemented on 8 pixels which improves the SNR of the system with a factor of √8. Oversampling rate of 3 improves the spatial resolution of the system. TDI operation is realized with a novel under-pixel analog-to-digital converter, which improves the noise performance of ROIC with a lower quantization noise. Since analog signal is converted to digital domain in-pixel, non-uniformities and inaccuracies due to analog signal routing over large chip area is eliminated. Contributions of each pixel for proper TDI operation are added in summation counters, no op-amps are used for summation, hence power consumption of ROIC is lower than its analog counterparts. Due to lack of multiple capacitors or summation amplifiers, ROIC occupies smaller chip area compared to its analog counterparts. ROIC is also superior to its digital counterparts due to novel digital TDI implementation in terms of power consumption, noise and chip area. ROIC supports bi-directional scan, multiple gain settings, bypass operation, automatic gain adjustment, pixel select/deselect, and is programmable through serial or parallel interface. Input referred noise of ROIC is less than 750 rms electrons, while power consumption is less than 20mW. ROIC is designed to perform both in room and cryogenic temperatures.
{"title":"Design of 90×8 ROIC with pixel level digital TDI implementation for scanning type LWIR FPAs","authors":"O. Ceylan, Huseyin Kayahan, M. Yazici, Y. Gurbuz","doi":"10.1117/12.2018554","DOIUrl":"https://doi.org/10.1117/12.2018554","url":null,"abstract":"Design of a 90×8 CMOS readout integrated circuit (ROIC) based on pixel level digital time delay integration (TDI) for scanning type LWIR focal plane arrays (FPAs) is presented. TDI is implemented on 8 pixels which improves the SNR of the system with a factor of √8. Oversampling rate of 3 improves the spatial resolution of the system. TDI operation is realized with a novel under-pixel analog-to-digital converter, which improves the noise performance of ROIC with a lower quantization noise. Since analog signal is converted to digital domain in-pixel, non-uniformities and inaccuracies due to analog signal routing over large chip area is eliminated. Contributions of each pixel for proper TDI operation are added in summation counters, no op-amps are used for summation, hence power consumption of ROIC is lower than its analog counterparts. Due to lack of multiple capacitors or summation amplifiers, ROIC occupies smaller chip area compared to its analog counterparts. ROIC is also superior to its digital counterparts due to novel digital TDI implementation in terms of power consumption, noise and chip area. ROIC supports bi-directional scan, multiple gain settings, bypass operation, automatic gain adjustment, pixel select/deselect, and is programmable through serial or parallel interface. Input referred noise of ROIC is less than 750 rms electrons, while power consumption is less than 20mW. ROIC is designed to perform both in room and cryogenic temperatures.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133634973","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}
H. Sharifi, M. Roebuck, T. De Lyon, H. Nguyen, M. Cline, D. Chang, D. Yap, S. Mehta, R. Rajavel, A. Ionescu, A. D'Souza, E. Robinson, D. Okerlund, N. Dhar
We describe our recent efforts in developing visible to mid-wave (0.5 µm to 5.0 µm) broadband photon-trap InAsSb-based infrared detectors grown on GaAs substrates operating at high temperature (150-200K) with low dark current and high quantum efficiency. Utilizing an InAsSb absorber on GaAs substrates instead of an HgCdTe absorber will enable low-cost fabrication of large-format, high operating temperature focal plane arrays. We have utilized a novel detector design based-on pyramidal photon trapping InAsSb structures in conjunction with compound barrier-based device architecture to suppress both G-R dark current, as well as diffusion current through absorber volume reduction. Our optical simulation show that our engineered pyramid structures minimize the surface reflection compared to conventional diode structures acting as a broadband anti-reflective coating (AR). In addition, it exhibits > 70-80% absorption over the entire 0.5 µm to 5.0 µm spectral range while providing up to 3× reduction in absorber volume. Lattice-mismatched InAs0.82Sb0.18 with 5.25 µm cutoff at 200K was grown on GaAs substrates. 128×128/60μm and 1024×1024/18μm detector arrays that consist of bulk absorber as well as photon-trap pyramid structures were fabricated to compare the detector performance. The measured dark current density for the diodes with the pyramidal absorber was 3× lower that for the conventional diode with the bulk absorber, which is consistent with the volume reduction due to the creation of the pyramidal absorber topology. We have achieved high D* (< 1.0 x 1010 cm √Hz/W) and maintain very high (< 80 %) internal quantum efficiency over the entire band 0.5 to 5 µm spectral band at 200K.
我们描述了我们最近在开发可见光到中波(0.5µm至5.0µm)宽带光子阱inassb红外探测器方面的努力，该探测器生长在高温(150-200K)下的GaAs衬底上，具有低暗电流和高量子效率。在GaAs衬底上使用InAsSb吸收体而不是HgCdTe吸收体将使大尺寸、高工作温度焦平面阵列的低成本制造成为可能。我们利用了一种基于金字塔光子捕获InAsSb结构的新型探测器设计，结合基于复合势垒的器件结构来抑制G-R暗电流，以及通过吸收体体积减小来抑制扩散电流。我们的光学模拟表明，与作为宽带抗反射涂层(AR)的传统二极管结构相比，我们的工程金字塔结构最大限度地减少了表面反射。此外，它在整个0.5µm至5.0µm光谱范围内具有> 70-80%的吸收，同时吸收体体积减少了3倍。在GaAs衬底上生长了晶格不匹配的InAs0.82Sb0.18，截止温度为5.25µm，温度为200K。制作了由体吸收体和光子阱金字塔结构组成的探测器阵列128×128/60μm和1024×1024/18μm来比较探测器的性能。采用金字塔吸收体的二极管的测量暗电流密度比采用体吸收体的传统二极管低3倍，这与由于金字塔吸收体拓扑结构的产生而导致的体积减小是一致的。我们已经实现了高D* (< 1.0 x 1010 cm√Hz/W)，并在200K下在整个0.5至5µm光谱波段保持了非常高的内部量子效率(< 80%)。
{"title":"Fabrication of high-operating temperature (HOT), visible to MWIR, nCBn photon-trap detector arrays","authors":"H. Sharifi, M. Roebuck, T. De Lyon, H. Nguyen, M. Cline, D. Chang, D. Yap, S. Mehta, R. Rajavel, A. Ionescu, A. D'Souza, E. Robinson, D. Okerlund, N. Dhar","doi":"10.1117/12.2015083","DOIUrl":"https://doi.org/10.1117/12.2015083","url":null,"abstract":"We describe our recent efforts in developing visible to mid-wave (0.5 µm to 5.0 µm) broadband photon-trap InAsSb-based infrared detectors grown on GaAs substrates operating at high temperature (150-200K) with low dark current and high quantum efficiency. Utilizing an InAsSb absorber on GaAs substrates instead of an HgCdTe absorber will enable low-cost fabrication of large-format, high operating temperature focal plane arrays. We have utilized a novel detector design based-on pyramidal photon trapping InAsSb structures in conjunction with compound barrier-based device architecture to suppress both G-R dark current, as well as diffusion current through absorber volume reduction. Our optical simulation show that our engineered pyramid structures minimize the surface reflection compared to conventional diode structures acting as a broadband anti-reflective coating (AR). In addition, it exhibits > 70-80% absorption over the entire 0.5 µm to 5.0 µm spectral range while providing up to 3× reduction in absorber volume. Lattice-mismatched InAs0.82Sb0.18 with 5.25 µm cutoff at 200K was grown on GaAs substrates. 128×128/60μm and 1024×1024/18μm detector arrays that consist of bulk absorber as well as photon-trap pyramid structures were fabricated to compare the detector performance. The measured dark current density for the diodes with the pyramidal absorber was 3× lower that for the conventional diode with the bulk absorber, which is consistent with the volume reduction due to the creation of the pyramidal absorber topology. We have achieved high D* (< 1.0 x 1010 cm √Hz/W) and maintain very high (< 80 %) internal quantum efficiency over the entire band 0.5 to 5 µm spectral band at 200K.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128223348","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}
H. Haan, Timo Feuchter, M. Münzberg, J. Fritze, H. Schlemmer
The video output of thermal imagers stayed constant over almost two decades. When the famous Common Modules were employed a thermal image at first was presented to the observer in the eye piece only. In the early 1990s TV cameras were attached and the standard output was CCIR. In the civil camera market output standards changed to digital formats a decade ago with digital video streaming being nowadays state-of-the-art. The reasons why the output technique in the thermal world stayed unchanged over such a long time are: the very conservative view of the military community, long planning and turn-around times of programs and a slower growth of pixel number of TIs in comparison to consumer cameras. With megapixel detectors the CCIR output format is not sufficient any longer. The paper discusses the state-of-the-art compression and streaming solutions for TIs.
{"title":"Thermal imagers: from ancient analog video output to state-of-the-art video streaming","authors":"H. Haan, Timo Feuchter, M. Münzberg, J. Fritze, H. Schlemmer","doi":"10.1117/12.2015705","DOIUrl":"https://doi.org/10.1117/12.2015705","url":null,"abstract":"The video output of thermal imagers stayed constant over almost two decades. When the famous Common Modules were employed a thermal image at first was presented to the observer in the eye piece only. In the early 1990s TV cameras were attached and the standard output was CCIR. In the civil camera market output standards changed to digital formats a decade ago with digital video streaming being nowadays state-of-the-art. The reasons why the output technique in the thermal world stayed unchanged over such a long time are: the very conservative view of the military community, long planning and turn-around times of programs and a slower growth of pixel number of TIs in comparison to consumer cameras. With megapixel detectors the CCIR output format is not sufficient any longer. The paper discusses the state-of-the-art compression and streaming solutions for TIs.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114635458","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}
P. Klipstein, Y. Gross, D. Aronov, M. ben Ezra, E. Berkowicz, Y. Cohen, R. Fraenkel, A. Glozman, S. Grossman, O. Klin, I. Lukomsky, T. Marlowitz, L. Shkedy, I. Shtrichman, N. Snapi, A. Tuito, M. Yassen, E. Weiss
Over the past few years, a new type of High Operating Temperature (HOT) photon detector has been developed at SCD, which operates in the blue part of the MWIR window of the atmosphere (3.4-4.2 μm). This window is generally more transparent than the red part of the MWIR window (4.4-4.9 μm), especially for mid and long range applications. The detector has an InAsSb active layer, and is based on the new "XBn" device concept. We have analyzed various electrooptical systems at different atmospheric temperatures, based on XBn-InAsSb operating at 150K and epi-InSb at 95K, respectively, and find that the typical recognition ranges of both detector technologies are similar. Therefore, for very many applications there is no disadvantage to using XBn-InAsSb instead of InSb. On the other hand XBn technology confers many advantages, particularly in low Size, Weight and Power (SWaP) and in the high reliability of the cooler and Integrated Detector Cooler Assembly (IDCA). In this work we present a new IDCA, designed for 150K operation. The 15 μm pitch 640×512 digital FPA is housed in a robust, light-weight, miniaturised Dewar, attached to Ricor's K562S Stirling cycle cooler. The complete IDCA has a diameter of 28 mm, length of 80 mm and weight of < 300 gm. The total IDCA power consumption is ~ 3W at a 60Hz frame rate, including an external miniature proximity card attached to the outside of the Dewar. We describe some of the key performance parameters of the new detector, including its NETD, RNU and operability, pixel cross-talk, and early stage yield results from our production line.
{"title":"Low SWaP MWIR detector based on XBn focal plane array","authors":"P. Klipstein, Y. Gross, D. Aronov, M. ben Ezra, E. Berkowicz, Y. Cohen, R. Fraenkel, A. Glozman, S. Grossman, O. Klin, I. Lukomsky, T. Marlowitz, L. Shkedy, I. Shtrichman, N. Snapi, A. Tuito, M. Yassen, E. Weiss","doi":"10.1117/12.2015747","DOIUrl":"https://doi.org/10.1117/12.2015747","url":null,"abstract":"Over the past few years, a new type of High Operating Temperature (HOT) photon detector has been developed at SCD, which operates in the blue part of the MWIR window of the atmosphere (3.4-4.2 μm). This window is generally more transparent than the red part of the MWIR window (4.4-4.9 μm), especially for mid and long range applications. The detector has an InAsSb active layer, and is based on the new \"XBn\" device concept. We have analyzed various electrooptical systems at different atmospheric temperatures, based on XBn-InAsSb operating at 150K and epi-InSb at 95K, respectively, and find that the typical recognition ranges of both detector technologies are similar. Therefore, for very many applications there is no disadvantage to using XBn-InAsSb instead of InSb. On the other hand XBn technology confers many advantages, particularly in low Size, Weight and Power (SWaP) and in the high reliability of the cooler and Integrated Detector Cooler Assembly (IDCA). In this work we present a new IDCA, designed for 150K operation. The 15 μm pitch 640×512 digital FPA is housed in a robust, light-weight, miniaturised Dewar, attached to Ricor's K562S Stirling cycle cooler. The complete IDCA has a diameter of 28 mm, length of 80 mm and weight of < 300 gm. The total IDCA power consumption is ~ 3W at a 60Hz frame rate, including an external miniature proximity card attached to the outside of the Dewar. We describe some of the key performance parameters of the new detector, including its NETD, RNU and operability, pixel cross-talk, and early stage yield results from our production line.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123942242","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}
Many design approaches to the color correction of infrared optics have evolved from theories based on first-order linear equations. When faced with broad spectral design, however, such technologies can fall short. The use of linear approximations for certain material properties has limited the development of well-corrected lenses when faced with higher order color and aberration correction. In this paper we will discuss broad spectral multi-band imaging with specific emphasis on a fast catadioptric wide-angle system design, highlighting its advantages and disadvantages. The result of this work will illustrate an improved solution yielding a compact well-corrected lens adapted for use in the broadband spectrum.
{"title":"Wide-angle catadioptric optics for broadband applications","authors":"Naomi J. Pollica, C. Alexay","doi":"10.1117/12.2018915","DOIUrl":"https://doi.org/10.1117/12.2018915","url":null,"abstract":"Many design approaches to the color correction of infrared optics have evolved from theories based on first-order linear equations. When faced with broad spectral design, however, such technologies can fall short. The use of linear approximations for certain material properties has limited the development of well-corrected lenses when faced with higher order color and aberration correction. In this paper we will discuss broad spectral multi-band imaging with specific emphasis on a fast catadioptric wide-angle system design, highlighting its advantages and disadvantages. The result of this work will illustrate an improved solution yielding a compact well-corrected lens adapted for use in the broadband spectrum.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129728600","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. D'Souza, E. Robinson, A. Ionescu, D. Okerlund, T. De Lyon, R. Rajavel, H. Sharifi, N. Dhar, P. Wijewarnasuriya, C. Grein
Mid-wavelength infrared (MWIR) InAsSb alloy barrier detectors grown on GaAs substrates were characterized as a function of temperature to evaluate their performance. Detector arrays were fabricated in a 1024 × 1024 format on an 18 μm pitch. A fanout was utilized to directly acquire data from a set of selected detectors without an intervening read out integrating circuit (ROIC). The detectors have a cutoff wavelength equal to ~ 4.9 μm at 150 K. The peak internal quantum efficiency (QE) required a reverse bias voltage of 1 V. The detectors were diffusion-limited at the bias required to attain peak QE. Multiple 18 μm × 18 μm detectors were tied together in parallel by connecting the indium bump of each detector to a single large metal pad on the fanout. The dark current density at -1 V bias for a set of 64 × 64 and 6 × 6 array of detectors, each of which were tied together in parallel was ~ 10-3 A/cm2 at 200 K and 5 × 10-6 A/cm2 at 150 K. The 4096 (64 × 64) and 36 (6 × 6) detectors, both have similar Jdark vs Vd characteristics, demonstrating high operability and uniformity of the detectors in the array. The external QE measured using a narrow band filter centered at ~ 4 μm had values in the 65 – 70 % range. Since the detectors were illuminated through a GaAs substrate which has a reflectance of 29%, the internal QE is greater than 90 %. A 1024 × 1024 ROIC on an 18 μm pitch was also designed and fabricated to interface with the barrier detectors. QE at 150 K for a 1024 × 1024 detector array hybridized to a ROIC matched the QE measured on detectors that were measured directly through a fanout chip. Median D* at 150 K under a flux of 1.07 × 1015 ph/(cm2/s was 1.0 x 1011 cm Hz1/2 /W.
{"title":"MWIR InAsSb barrier detector data and analysis","authors":"A. D'Souza, E. Robinson, A. Ionescu, D. Okerlund, T. De Lyon, R. Rajavel, H. Sharifi, N. Dhar, P. Wijewarnasuriya, C. Grein","doi":"10.1117/12.2018427","DOIUrl":"https://doi.org/10.1117/12.2018427","url":null,"abstract":"Mid-wavelength infrared (MWIR) InAsSb alloy barrier detectors grown on GaAs substrates were characterized as a function of temperature to evaluate their performance. Detector arrays were fabricated in a 1024 × 1024 format on an 18 μm pitch. A fanout was utilized to directly acquire data from a set of selected detectors without an intervening read out integrating circuit (ROIC). The detectors have a cutoff wavelength equal to ~ 4.9 μm at 150 K. The peak internal quantum efficiency (QE) required a reverse bias voltage of 1 V. The detectors were diffusion-limited at the bias required to attain peak QE. Multiple 18 μm × 18 μm detectors were tied together in parallel by connecting the indium bump of each detector to a single large metal pad on the fanout. The dark current density at -1 V bias for a set of 64 × 64 and 6 × 6 array of detectors, each of which were tied together in parallel was ~ 10-3 A/cm2 at 200 K and 5 × 10-6 A/cm2 at 150 K. The 4096 (64 × 64) and 36 (6 × 6) detectors, both have similar Jdark vs Vd characteristics, demonstrating high operability and uniformity of the detectors in the array. The external QE measured using a narrow band filter centered at ~ 4 μm had values in the 65 – 70 % range. Since the detectors were illuminated through a GaAs substrate which has a reflectance of 29%, the internal QE is greater than 90 %. A 1024 × 1024 ROIC on an 18 μm pitch was also designed and fabricated to interface with the barrier detectors. QE at 150 K for a 1024 × 1024 detector array hybridized to a ROIC matched the QE measured on detectors that were measured directly through a fanout chip. Median D* at 150 K under a flux of 1.07 × 1015 ph/(cm2/s was 1.0 x 1011 cm Hz1/2 /W.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125323301","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}
B. Lemoff, Robert B. Martin, M. Sluch, Kristopher M. Kafka, William McCormick, R. Ice
Positive identification of personnel from a safe distance is a long-standing need for security and defense applications. Advances in computer face recognition have made this a reliable means of identification when facial imagery of sufficient resolution is available to be matched against a database of mug shots. Long-range identification at night requires that the face be actively illuminated; however, for visible and NIR illumination, the intensity required to produce high-resolution long-range imagery typically creates an eye-safety hazard. SWIR illumination makes active- SWIR imaging a promising approach to long-range night-time identification. We will describe an active-SWIR imaging system that is being developed to covertly detect, track, zoom in on, and positively identify a human target, night or day, at hundreds of meters range. The SWIR illuminator pans, tilts, and zooms with the imager to always just fill the imager field of view. The illuminator meets Class 1 eye-safety limits (safe even with magnifying optics) at the intended target, and meets Class 1M eye-safety limits (safe to the naked eye) at point-blank range. Close-up night-time facial imagery will be presented along with experimental face recognition performance results for matching SWIR imagery to a database of visible mug shots at distance.
{"title":"Long-range night/day human identification using active-SWIR imaging","authors":"B. Lemoff, Robert B. Martin, M. Sluch, Kristopher M. Kafka, William McCormick, R. Ice","doi":"10.1117/12.2016335","DOIUrl":"https://doi.org/10.1117/12.2016335","url":null,"abstract":"Positive identification of personnel from a safe distance is a long-standing need for security and defense applications. Advances in computer face recognition have made this a reliable means of identification when facial imagery of sufficient resolution is available to be matched against a database of mug shots. Long-range identification at night requires that the face be actively illuminated; however, for visible and NIR illumination, the intensity required to produce high-resolution long-range imagery typically creates an eye-safety hazard. SWIR illumination makes active- SWIR imaging a promising approach to long-range night-time identification. We will describe an active-SWIR imaging system that is being developed to covertly detect, track, zoom in on, and positively identify a human target, night or day, at hundreds of meters range. The SWIR illuminator pans, tilts, and zooms with the imager to always just fill the imager field of view. The illuminator meets Class 1 eye-safety limits (safe even with magnifying optics) at the intended target, and meets Class 1M eye-safety limits (safe to the naked eye) at point-blank range. Close-up night-time facial imagery will be presented along with experimental face recognition performance results for matching SWIR imagery to a database of visible mug shots at distance.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"125 22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121740641","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}
Numerical simulations play an important role in the development of large-format infrared detector array tech- nologies, especially when considering devices whose sizes are comparable to the wavelength of the radiation they are detecting. Computational models can be used to predict the optical and electrical response of such devices and evaluate designs prior to fabrication. We have developed a simulation framework which solves Maxwell’s equations to determine the electromagnetic properties of a detector and subsequently uses a drift-diffusion ap- proach to asses the electrical response. We apply these techniques to gauge the effects of cathode placement on the inter- and intra-pixel attributes of compositionally graded and constant Hg1−xCdxTe mid-wavelength infrared detectors. In particular, the quantum efficiency, nearest-neighbor crosstalk, and modulation transfer function are evaluated for several device architectures.
{"title":"Large-scale numerical simulation of reduced-pitch HgCdTe infrared detector arrays","authors":"B. Pinkie, E. Bellotti","doi":"10.1117/12.2016186","DOIUrl":"https://doi.org/10.1117/12.2016186","url":null,"abstract":"Numerical simulations play an important role in the development of large-format infrared detector array tech- nologies, especially when considering devices whose sizes are comparable to the wavelength of the radiation they are detecting. Computational models can be used to predict the optical and electrical response of such devices and evaluate designs prior to fabrication. We have developed a simulation framework which solves Maxwell’s equations to determine the electromagnetic properties of a detector and subsequently uses a drift-diffusion ap- proach to asses the electrical response. We apply these techniques to gauge the effects of cathode placement on the inter- and intra-pixel attributes of compositionally graded and constant Hg1−xCdxTe mid-wavelength infrared detectors. In particular, the quantum efficiency, nearest-neighbor crosstalk, and modulation transfer function are evaluated for several device architectures.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115225449","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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