A. Zelazny, R. Benson, J. Deegan, K. Walsh, W. D. Schmidt, R. Howe
We describe the benefits to camera system SWaP-C associated with the use of aspheric molded glasses and optical polymers in the design and manufacture of optical components and elements. Both camera objectives and display eyepieces, typical for night vision man-portable EO/IR systems, are explored. We discuss optical trade-offs, system performance, and cost reductions associated with this approach in both visible and non-visible wavebands, specifically NIR and LWIR. Example optical models are presented, studied, and traded using this approach.
{"title":"Optical methods for the optimization of system SWaP-C using aspheric components and advanced optical polymers","authors":"A. Zelazny, R. Benson, J. Deegan, K. Walsh, W. D. Schmidt, R. Howe","doi":"10.1117/12.2015475","DOIUrl":"https://doi.org/10.1117/12.2015475","url":null,"abstract":"We describe the benefits to camera system SWaP-C associated with the use of aspheric molded glasses and optical polymers in the design and manufacture of optical components and elements. Both camera objectives and display eyepieces, typical for night vision man-portable EO/IR systems, are explored. We discuss optical trade-offs, system performance, and cost reductions associated with this approach in both visible and non-visible wavebands, specifically NIR and LWIR. Example optical models are presented, studied, and traded using this approach.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"4 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":"129125794","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}
J. Rollin, F. Diaz, C. Fontaine, B. Loiseaux, M. Lee, Christophe Clienti, F. Lemonnier, Xianghua Zhang, L. Calvez
The military uncooled infrared market is driven by the continued cost reduction of the focal plane arrays whilst maintaining high standards of sensitivity and steering towards smaller pixel sizes. As a consequence, new optical solutions are called for. Two approaches can come into play: the bottom up option consists in allocating improvements to each contributor and the top down process rather relies on an overall optimization of the complete image channel. The University of Rennes I with Thales Angénieux alongside has been working over the past decade through French MOD funding’s, on low cost alternatives of infrared materials based upon chalcogenide glasses. A special care has been laid on the enhancement of their mechanical properties and their ability to be moulded according to complex shapes. New manufacturing means developments capable of better yields for the raw materials will be addressed, too. Beyond the mere lenses budget cuts, a wave front coding process can ease a global optimization. This technic gives a way of relaxing optical constraints or upgrading thermal device performances through an increase of the focus depths and desensitization against temperature drifts: it combines image processing and the use of smart optical components. Thales achievements in such topics will be enlightened and the trade-off between image quality correction levels and low consumption/ real time processing, as might be required in hand-free night vision devices, will be emphasized. It is worth mentioning that both approaches are deeply leaning on each other.
{"title":"New solutions and technologies for uncooled infrared imaging","authors":"J. Rollin, F. Diaz, C. Fontaine, B. Loiseaux, M. Lee, Christophe Clienti, F. Lemonnier, Xianghua Zhang, L. Calvez","doi":"10.1117/12.2015784","DOIUrl":"https://doi.org/10.1117/12.2015784","url":null,"abstract":"The military uncooled infrared market is driven by the continued cost reduction of the focal plane arrays whilst maintaining high standards of sensitivity and steering towards smaller pixel sizes. As a consequence, new optical solutions are called for. Two approaches can come into play: the bottom up option consists in allocating improvements to each contributor and the top down process rather relies on an overall optimization of the complete image channel. The University of Rennes I with Thales Angénieux alongside has been working over the past decade through French MOD funding’s, on low cost alternatives of infrared materials based upon chalcogenide glasses. A special care has been laid on the enhancement of their mechanical properties and their ability to be moulded according to complex shapes. New manufacturing means developments capable of better yields for the raw materials will be addressed, too. Beyond the mere lenses budget cuts, a wave front coding process can ease a global optimization. This technic gives a way of relaxing optical constraints or upgrading thermal device performances through an increase of the focus depths and desensitization against temperature drifts: it combines image processing and the use of smart optical components. Thales achievements in such topics will be enlightened and the trade-off between image quality correction levels and low consumption/ real time processing, as might be required in hand-free night vision devices, will be emphasized. It is worth mentioning that both approaches are deeply leaning on each other.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"185 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":"123397631","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. Karim, O. Gustafsson, S. Savage, Qin Wang, S. Almqvist, C. Asplund, M. Hammar, J. Andersson
We report on the device characterization of In(Ga)Sb/InAs quantum dots (QDs) based photodetectors for long wave IR detectors. The detection principle of these quantum-dot infrared photodetectors (QDIPs) is based on the spatially indirect transition between the In(Ga)Sb QDs and the InAs matrix, as a result of the type-II band alignment. Such photodetectors are expected to have lower dark currents and higher operating temperatures compared to the current state of the art InSb and mercury cadmium telluride (MCT) technology. The In(Ga)Sb QD structures were grown using metal-organic vapour-phase epitaxy and explored using structural, electrical and optical characterization techniques. Material development resulted in obtaining photoluminescence up to 10 μm, which is the longest wavelength reported in this material system. We have fabricated different photovoltaic IR detectors from the developed material that show absorption up to 8 μm. Photoresponse spectra, showing In(Ga)Sb QD related absorption edge, were obtained up to 200 K. Detectors with different In(Ga)Sb QDs showing different cut-off wavelengths were investigated for photoresponse. Photoresponse in these detectors is thermally activated with different activation energies for devices with different cut-off wavelengths. Devices with longer cut-off wavelength exhibit higher activation energies. We can interpret this using the energy band diagram of the dots/matrix system for different QD sizes.
{"title":"In(Ga)Sb/InAs quantum dot based IR photodetectors with thermally activated photoresponse","authors":"A. Karim, O. Gustafsson, S. Savage, Qin Wang, S. Almqvist, C. Asplund, M. Hammar, J. Andersson","doi":"10.1117/12.2015820","DOIUrl":"https://doi.org/10.1117/12.2015820","url":null,"abstract":"We report on the device characterization of In(Ga)Sb/InAs quantum dots (QDs) based photodetectors for long wave IR detectors. The detection principle of these quantum-dot infrared photodetectors (QDIPs) is based on the spatially indirect transition between the In(Ga)Sb QDs and the InAs matrix, as a result of the type-II band alignment. Such photodetectors are expected to have lower dark currents and higher operating temperatures compared to the current state of the art InSb and mercury cadmium telluride (MCT) technology. The In(Ga)Sb QD structures were grown using metal-organic vapour-phase epitaxy and explored using structural, electrical and optical characterization techniques. Material development resulted in obtaining photoluminescence up to 10 μm, which is the longest wavelength reported in this material system. We have fabricated different photovoltaic IR detectors from the developed material that show absorption up to 8 μm. Photoresponse spectra, showing In(Ga)Sb QD related absorption edge, were obtained up to 200 K. Detectors with different In(Ga)Sb QDs showing different cut-off wavelengths were investigated for photoresponse. Photoresponse in these detectors is thermally activated with different activation energies for devices with different cut-off wavelengths. Devices with longer cut-off wavelength exhibit higher activation energies. We can interpret this using the energy band diagram of the dots/matrix system for different QD sizes.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"139 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":"131481363","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 the 8-12 micron waveband Focal Plane Arrays (FPA) are available with a pixel pitch of 12 microns or less. High resolution FPAs with VGA, XGA and SXGA resolution should become available at a reasonable price. These will require new lens designs to give the required fields of view. The challenge for the Optical Designer is to design lenses when the pixel pitch of the detector is the same as the wavelength of the light imaged. The lens specification will need to give more thought to the resolution required by the system. A smaller pixel pitch detector defines a requirement for a shorter focal length to give the same field of view. This will have a number of effects upon the lens design. Geometrical aberrations decrease proportionally with the focal length. Reverse telephoto layouts will become more common, particularly when the system has a shutter. The increase in pixel count will require wide field of view lenses which present particular challenges. The impact of diffraction effects on the lens design is considerably increased. The fast F-number causes an increase in the diffraction limit of the system, but also increases geometric aberrations by a cube law. Therefore the balance between the diffraction limited and the aberration limited performance becomes more difficult. The first approach of the designer is to re-use proven designs originally intended for use with 17micron detectors. Some of these designs will have adequate performance at the Nyquist limit of the 12 micron detectors. Even smaller detector pitches, such as 10 micron, will demand new approaches to Infra Red lens design. The traditional approach will quickly increase the number of elements to 3 or even more. This could lead to the lenses with medium fields of view driving the system cost. A close cooperation between the camera developer and lens designer will become necessary in order to explore alternate approaches, such as wavefront coding, in order to reach the most cost effective solution.
{"title":"Challenges, constraints and results of lens design in 8-12micron waveband for bolometer-FPAs having a pixel pitch 12micron","authors":"N. Schuster, J. Franks","doi":"10.1117/12.2021637","DOIUrl":"https://doi.org/10.1117/12.2021637","url":null,"abstract":"In the 8-12 micron waveband Focal Plane Arrays (FPA) are available with a pixel pitch of 12 microns or less. High resolution FPAs with VGA, XGA and SXGA resolution should become available at a reasonable price. These will require new lens designs to give the required fields of view. The challenge for the Optical Designer is to design lenses when the pixel pitch of the detector is the same as the wavelength of the light imaged. The lens specification will need to give more thought to the resolution required by the system. A smaller pixel pitch detector defines a requirement for a shorter focal length to give the same field of view. This will have a number of effects upon the lens design. Geometrical aberrations decrease proportionally with the focal length. Reverse telephoto layouts will become more common, particularly when the system has a shutter. The increase in pixel count will require wide field of view lenses which present particular challenges. The impact of diffraction effects on the lens design is considerably increased. The fast F-number causes an increase in the diffraction limit of the system, but also increases geometric aberrations by a cube law. Therefore the balance between the diffraction limited and the aberration limited performance becomes more difficult. The first approach of the designer is to re-use proven designs originally intended for use with 17micron detectors. Some of these designs will have adequate performance at the Nyquist limit of the 12 micron detectors. Even smaller detector pitches, such as 10 micron, will demand new approaches to Infra Red lens design. The traditional approach will quickly increase the number of elements to 3 or even more. This could lead to the lenses with medium fields of view driving the system cost. A close cooperation between the camera developer and lens designer will become necessary in order to explore alternate approaches, such as wavefront coding, in order to reach the most cost effective solution.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"58 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":"129811419","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}
We report lattice-mismatched, uncooled, 2.2 µm wavelength cutoff, InGaAs photodiodes and balanced photoreceivers with bandwidth up to 25 GHz. The responsivity at 2.05 µm is 1.2 A/W, and the 1 dB compression, optical current handling of these photodiodes is 10 mA at 7 V reverse bias. Such high current handling capacity allows these photodiodes to operate with a higher DC local oscillator (LO) power, thus, allowing more coherent gain and shot noise limited operation. The impulse response of these devices show rise time / fall time of ~15 ps, and full width half maximum of ~20 ps.
{"title":"2.2 micron, uncooled, InGaAs photodiodes, and balanced photoreceivers up to 25 GHz bandwidth","authors":"A. Joshi, S. Datta, M. Lange","doi":"10.1117/12.2015593","DOIUrl":"https://doi.org/10.1117/12.2015593","url":null,"abstract":"We report lattice-mismatched, uncooled, 2.2 µm wavelength cutoff, InGaAs photodiodes and balanced photoreceivers with bandwidth up to 25 GHz. The responsivity at 2.05 µm is 1.2 A/W, and the 1 dB compression, optical current handling of these photodiodes is 10 mA at 7 V reverse bias. Such high current handling capacity allows these photodiodes to operate with a higher DC local oscillator (LO) power, thus, allowing more coherent gain and shot noise limited operation. The impulse response of these devices show rise time / fall time of ~15 ps, and full width half maximum of ~20 ps.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"129 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114090515","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 presents one-dimensional numerical simulations and analytical modeling of ideal (only diffusion current and only Auger-1 and radiative recombination) InAs nBn detectors having n-type barrier layers, with donor concentrations ranging from 1.8×1015 to 2.5×1016 cm-3. We examine quantitatively the three space charge regions in the nBn detector with an n-type barrier layer (BL), and determine criteria for combinations of bias voltage and BL donor concentration that allow operation of the nBn with no depletion region in the narrow-gap absorber layer (AL) or contact layer (CL). We determine the quantitative characteristics of the valence band barrier that is present for an n-type BL. From solution of Poisson’s equation in the uniformly doped BL, we derive analytical expressions for the valence band barrier heights versus bias voltage for holes in both the AL and the CL. These expressions show that the VB barrier height varies linearly with the BL donor concentration and as the square of the BL width. Using these expressions, we constructed a phenomenological equation for the dark current density versus bias voltage which agrees reasonably well with the shape of the J(V) curves from numerical simulations. Our simulations suggest that the nBn detector should be able to be operated at or near zero-bias voltage.
{"title":"Numerical simulation of InAs nBn infrared detectors with n-type barrier layers","authors":"M. Reine, B. Pinkie, J. Schuster, E. Bellotti","doi":"10.1117/12.2016150","DOIUrl":"https://doi.org/10.1117/12.2016150","url":null,"abstract":"This paper presents one-dimensional numerical simulations and analytical modeling of ideal (only diffusion current and only Auger-1 and radiative recombination) InAs nBn detectors having n-type barrier layers, with donor concentrations ranging from 1.8×1015 to 2.5×1016 cm-3. We examine quantitatively the three space charge regions in the nBn detector with an n-type barrier layer (BL), and determine criteria for combinations of bias voltage and BL donor concentration that allow operation of the nBn with no depletion region in the narrow-gap absorber layer (AL) or contact layer (CL). We determine the quantitative characteristics of the valence band barrier that is present for an n-type BL. From solution of Poisson’s equation in the uniformly doped BL, we derive analytical expressions for the valence band barrier heights versus bias voltage for holes in both the AL and the CL. These expressions show that the VB barrier height varies linearly with the BL donor concentration and as the square of the BL width. Using these expressions, we constructed a phenomenological equation for the dark current density versus bias voltage which agrees reasonably well with the shape of the J(V) curves from numerical simulations. Our simulations suggest that the nBn detector should be able to be operated at or near zero-bias voltage.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"61 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":"130111296","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 echelle spectrograph can provide high resolving power (wavelength/FWHM) across a broad spectral range. These optical instruments are commonly used in spectroscopy for atomic and molecular identification in astronomical observations and laboratory analysis. The wavelength range of an echelle spectrograph is ultimately limited by the capabilities of the detector used to acquire the spectral data. Silicon based CCD, EMCCD and CMOS sensors typically enable measurements from 200nm to 1100nm. Infrared Laboratories and Catalina Scientific Instruments (CSI) have collaborated to demonstrate an application that combines IR Lab’s TRIWAVE camera with CSI’s EMU120/65 echelle spectrograph. The TRIWAVE camera covers a spectral range of 300nm to 1600nm, greatly increasing the wavelength range for applications using the EMU-120/65 spectrograph. With this increased capability, an opportunity exists for measuring the dielectric coating thickness of thin film by extracting and analyzing interference fringes from the spectral data. Methods and results of this measurement will be presented.
{"title":"Thin film coating analysis using a novel IR camera and a broadband Echelle spectrograph","authors":"S. Pappas, B. Beardsley, George Ritchie","doi":"10.1117/12.2016683","DOIUrl":"https://doi.org/10.1117/12.2016683","url":null,"abstract":"An echelle spectrograph can provide high resolving power (wavelength/FWHM) across a broad spectral range. These optical instruments are commonly used in spectroscopy for atomic and molecular identification in astronomical observations and laboratory analysis. The wavelength range of an echelle spectrograph is ultimately limited by the capabilities of the detector used to acquire the spectral data. Silicon based CCD, EMCCD and CMOS sensors typically enable measurements from 200nm to 1100nm. Infrared Laboratories and Catalina Scientific Instruments (CSI) have collaborated to demonstrate an application that combines IR Lab’s TRIWAVE camera with CSI’s EMU120/65 echelle spectrograph. The TRIWAVE camera covers a spectral range of 300nm to 1600nm, greatly increasing the wavelength range for applications using the EMU-120/65 spectrograph. With this increased capability, an opportunity exists for measuring the dielectric coating thickness of thin film by extracting and analyzing interference fringes from the spectral data. Methods and results of this measurement will be presented.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"110 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":"128001370","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}
Z. Tian, T. Schuler-Sandy, S. E. Godoy, H. Kim, J. Montoya, S. Myers, B. Klein, E. Plis, S. Krishna
Over the last several years, owing to the implementation of advanced device architectures, antimony-based type-II superlattice (T2-SL) infrared (IR) photodetectors and their focal plane arrays (FPAs) have achieved significant advancements. Here we present our recent effort towards the development of high operating temperature (HOT) mid-IR (MWIR) photodetectors, which utilizes an interband cascade scheme with discrete InAs/GaSb SL absorbers, sandwiched between electron and hole barriers. This low-noise device architecture has enabled background-limited operation above 150 K (300 K, 2π field-of-view), as well as above room temperature response in the mid-IR region. The detector yields a dark current density of 1.10×10-7 A/cm2 (1.44×10-3 A/cm2) at -5 mV, and a Johnson-limited D* of 2.22×1011 cmHz1/2/W (1.58×109 cmHz1/2/W) at 150 K (room temperature) and 3.6 μm, respectively. In this presentation, we will discuss the operation principles of the interband cascade design and our most recent progress in MWIR photodetectors toward high operating temperatures.
在过去的几年中，由于先进器件架构的实现，基于锑的ii型超晶格(T2-SL)红外(IR)光电探测器及其焦平面阵列(fpa)取得了重大进展。在这里，我们介绍了我们最近对高温(HOT)中红外(MWIR)光电探测器的开发所做的努力，该探测器采用带间级联方案，具有离散的InAs/GaSb SL吸收剂，夹在电子和空穴势垒之间。这种低噪声器件架构支持150 K (300 K, 2π视场)以上的背景限制工作，以及中红外区域高于室温的响应。该检测器在-5 mV时产生的暗电流密度为1.10×10-7 a /cm2 (1.44×10-3 a /cm2)，在150 K(室温)和3.6 μm时产生的约翰逊限D*分别为2.22×1011 cmHz1/2/W (1.58×109 cmHz1/2/W)。在本报告中，我们将讨论带间级联设计的工作原理以及我们在MWIR光电探测器的高温工作方面的最新进展。
{"title":"Quantum-engineered mid-infrared type-II InAs/GaSb superlattice photodetectors for high temperature operations","authors":"Z. Tian, T. Schuler-Sandy, S. E. Godoy, H. Kim, J. Montoya, S. Myers, B. Klein, E. Plis, S. Krishna","doi":"10.1117/12.2016125","DOIUrl":"https://doi.org/10.1117/12.2016125","url":null,"abstract":"Over the last several years, owing to the implementation of advanced device architectures, antimony-based type-II superlattice (T2-SL) infrared (IR) photodetectors and their focal plane arrays (FPAs) have achieved significant advancements. Here we present our recent effort towards the development of high operating temperature (HOT) mid-IR (MWIR) photodetectors, which utilizes an interband cascade scheme with discrete InAs/GaSb SL absorbers, sandwiched between electron and hole barriers. This low-noise device architecture has enabled background-limited operation above 150 K (300 K, 2π field-of-view), as well as above room temperature response in the mid-IR region. The detector yields a dark current density of 1.10×10-7 A/cm2 (1.44×10-3 A/cm2) at -5 mV, and a Johnson-limited D* of 2.22×1011 cmHz1/2/W (1.58×109 cmHz1/2/W) at 150 K (room temperature) and 3.6 μm, respectively. In this presentation, we will discuss the operation principles of the interband cascade design and our most recent progress in MWIR photodetectors toward high operating temperatures.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"76 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":"115203816","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 reports the development of a new microbolometer readout integrated circuit (MT3250BA) designed for high-resistance detector arrays. MT3250BA is the first microbolometer readout integrated circuit (ROIC) product from Mikro-Tasarim Ltd., which is a fabless IC design house specialized in the development of monolithic CMOS imaging sensors and ROICs for hybrid photonic imaging sensors and microbolometers. MT3250BA has a format of 320 × 256 and a pixel pitch of 50 µm, developed with a system-on-chip architecture in mind, where all the timing and biasing for this ROIC are generated on-chip without requiring any external inputs. MT3250BA is a highly configurable ROIC, where many of its features can be programmed through a 3-wire serial interface allowing on-the-fly configuration of many ROIC features. MT3250BA has 2 analog video outputs and 1 analog reference output for pseudo-differential operation, and the ROIC can be programmed to operate in the 1 or 2-output modes. A unique feature of MT3250BA is that it performs snapshot readout operation; therefore, the image quality will only be limited by the thermal time constant of the detector pixels, but not by the scanning speed of the ROIC, as commonly found in the conventional microbolometer ROICs performing line-by-line (rolling-line) readout operation. The signal integration is performed at the pixel level in parallel for the whole array, and signal integration time can be programmed from 0.1 µs up to 100 ms in steps of 0.1 µs. The ROIC is designed to work with high-resistance detector arrays with pixel resistance values higher than 250 kΩ. The detector bias voltage can be programmed on-chip over a 2 V range with a resolution of 1 mV. The ROIC has a measured input referred noise of 260 µV rms at 300 K. The ROIC can be used to build a microbolometer infrared sensor with an NETD value below 100 mK using a microbolometer detector array fabrication technology with a high detector resistance value (≥ 250 KΩ), a high TCR value (≥ 2.5 % / K), and a sufficiently low pixel thermal conductance (Gth ≤ 20 nW / K). The ROIC uses a single 3.3 V supply voltage and dissipates less than 75 mW in the 1-output mode at 60 fps. MT3250BA is fabricated using a mixed-signal CMOS process on 200 mm CMOS wafers, and tested wafers are available with test data and wafer map. A USB based compact test electronics and software are available for quick evaluation of this new microbolometer ROIC.
{"title":"MT3250BA: a 320×256-50µm snapshot microbolometer ROIC for high-resistance detector arrays","authors":"S. Eminoglu, T. Akin","doi":"10.1117/12.2019525","DOIUrl":"https://doi.org/10.1117/12.2019525","url":null,"abstract":"This paper reports the development of a new microbolometer readout integrated circuit (MT3250BA) designed for high-resistance detector arrays. MT3250BA is the first microbolometer readout integrated circuit (ROIC) product from Mikro-Tasarim Ltd., which is a fabless IC design house specialized in the development of monolithic CMOS imaging sensors and ROICs for hybrid photonic imaging sensors and microbolometers. MT3250BA has a format of 320 × 256 and a pixel pitch of 50 µm, developed with a system-on-chip architecture in mind, where all the timing and biasing for this ROIC are generated on-chip without requiring any external inputs. MT3250BA is a highly configurable ROIC, where many of its features can be programmed through a 3-wire serial interface allowing on-the-fly configuration of many ROIC features. MT3250BA has 2 analog video outputs and 1 analog reference output for pseudo-differential operation, and the ROIC can be programmed to operate in the 1 or 2-output modes. A unique feature of MT3250BA is that it performs snapshot readout operation; therefore, the image quality will only be limited by the thermal time constant of the detector pixels, but not by the scanning speed of the ROIC, as commonly found in the conventional microbolometer ROICs performing line-by-line (rolling-line) readout operation. The signal integration is performed at the pixel level in parallel for the whole array, and signal integration time can be programmed from 0.1 µs up to 100 ms in steps of 0.1 µs. The ROIC is designed to work with high-resistance detector arrays with pixel resistance values higher than 250 kΩ. The detector bias voltage can be programmed on-chip over a 2 V range with a resolution of 1 mV. The ROIC has a measured input referred noise of 260 µV rms at 300 K. The ROIC can be used to build a microbolometer infrared sensor with an NETD value below 100 mK using a microbolometer detector array fabrication technology with a high detector resistance value (≥ 250 KΩ), a high TCR value (≥ 2.5 % / K), and a sufficiently low pixel thermal conductance (Gth ≤ 20 nW / K). The ROIC uses a single 3.3 V supply voltage and dissipates less than 75 mW in the 1-output mode at 60 fps. MT3250BA is fabricated using a mixed-signal CMOS process on 200 mm CMOS wafers, and tested wafers are available with test data and wafer map. A USB based compact test electronics and software are available for quick evaluation of this new microbolometer ROIC.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"26 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":"122108409","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}
Reducing an array’s pixel pitch reduces the size and weight of the focal plane array (FPA) and its associated dewar, cooler and optics. Higher operating temperatures reduce cool-down time and cooler power, enabling reduced cooler size and weight. High operating temperature small pitch (≤15 um) infrared detectors are therefore highly desirable. We have characterized a large number of MWIR and LWIR FPAs as a function of temperature and cutoff wavelength to determine the impact of these parameters on the FPA’s dark current, 1/f noise and defects. The 77K cutoff wavelength range for the MWIR arrays was 5.0-5.6 um, and 8.5-11 um for the LWIR arrays. DRS’ HDVIP® FPAs are based on a front-side illuminated, via interconnected, cylindrical geometry, N+/N/P architecture. An FPA’s 1/f noise is manifested as a tail in the FPA’s rmsnoise distribution. We have found that the model-independent nonparametric skew [(mean–median)/standard deviation] of the rmsnoise distribution is a highly effective tool for quantifying the magnitude of an FPA’s 1/f noise tail. In this paper we show that a standard FPA’s 1/f noise varies as ni (the intrinsic carrier concentration), in agreement with models that treat dislocations as donor pipes located within the P-volume of the unit cell. Nonstandard FPAs have been observed with systemic 1/f noise which varies as ni2.
{"title":"Temperature dependence of 1/f noise, defects, and dark current in small pitch MWIR and LWIR HDVIP® HgCdTe FPAs","authors":"R. Strong, M. Kinch, J. Armstrong","doi":"10.1117/12.2015816","DOIUrl":"https://doi.org/10.1117/12.2015816","url":null,"abstract":"Reducing an array’s pixel pitch reduces the size and weight of the focal plane array (FPA) and its associated dewar, cooler and optics. Higher operating temperatures reduce cool-down time and cooler power, enabling reduced cooler size and weight. High operating temperature small pitch (≤15 um) infrared detectors are therefore highly desirable. We have characterized a large number of MWIR and LWIR FPAs as a function of temperature and cutoff wavelength to determine the impact of these parameters on the FPA’s dark current, 1/f noise and defects. The 77K cutoff wavelength range for the MWIR arrays was 5.0-5.6 um, and 8.5-11 um for the LWIR arrays. DRS’ HDVIP® FPAs are based on a front-side illuminated, via interconnected, cylindrical geometry, N+/N/P architecture. An FPA’s 1/f noise is manifested as a tail in the FPA’s rmsnoise distribution. We have found that the model-independent nonparametric skew [(mean–median)/standard deviation] of the rmsnoise distribution is a highly effective tool for quantifying the magnitude of an FPA’s 1/f noise tail. In this paper we show that a standard FPA’s 1/f noise varies as ni (the intrinsic carrier concentration), in agreement with models that treat dislocations as donor pipes located within the P-volume of the unit cell. Nonstandard FPAs have been observed with systemic 1/f noise which varies as ni2.","PeriodicalId":338283,"journal":{"name":"Defense, Security, and Sensing","volume":"70 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":"128586957","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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