为提高长波红外偏振成像系统中偏振器件性能,本文通过分析光栅材料及结构参数对光栅偏振性能的影响,设计并优化了一种双层材料构成的亚波长光栅。该光栅为矩形形貌,光栅区由铝与硒化锌构成,两种材料的厚度分别为0.6μm和0.4μm,光栅周期...为提高长波红外偏振成像系统中偏振器件性能,本文通过分析光栅材料及结构参数对光栅偏振性能的影响,设计并优化了一种双层材料构成的亚波长光栅。该光栅为矩形形貌,光栅区由铝与硒化锌构成,两种材料的厚度分别为0.6μm和0.4μm,光栅周期1μm,占空比50%。利用严格耦合波理论分析并计算该结构光栅的衍射效率,7~15μm波段的光以0~60°入射后其0级横磁模透射率达到87.54%以上,消光比超过47 d B。该光栅在10.6μm的测试波长下,TM透射率高达90.80%且具有50 d B以上的消光比,相比槽深相同的单层铝光栅,偏振透过率明显提高。仿真结果显示,该光栅在整个宽长波红外波段具有良好的偏振性能。展开更多
Pixel-wise Code Exposure (PCE) camera is one type of compressive sensing camera that has low power consumption and high compression ratio. Moreover, a PCE camera can control individual pixel exposure time that can ena...Pixel-wise Code Exposure (PCE) camera is one type of compressive sensing camera that has low power consumption and high compression ratio. Moreover, a PCE camera can control individual pixel exposure time that can enable high dynamic range. Conventional approaches of using PCE camera involve a time consuming and lossy process to reconstruct the original frames and then use those frames for target tracking and classification. In this paper, we present a deep learning approach that directly performs target tracking and classification in the compressive measurement domain without any frame reconstruction. Our approach has two parts: tracking and classification. The tracking has been done using YOLO (You Only Look Once) and the classification is achieved using Residual Network (ResNet). Extensive experiments using mid-wave infrared (MWIR) and long-wave infrared (LWIR) videos demonstrated the efficacy of our proposed approach.展开更多
This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃...This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.展开更多
随着碲镉汞(HgCdTe)红外探测器的不断发展,碲镉汞波长已经逐渐从中波向长波/甚长波方向发展,表面效应很大程度上决定了碲镉汞红外焦平面探测器的性能,因此对表面钝化提出了更高的要求。文中通过研究磁控溅射生长的钝化层进行三温段退火...随着碲镉汞(HgCdTe)红外探测器的不断发展,碲镉汞波长已经逐渐从中波向长波/甚长波方向发展,表面效应很大程度上决定了碲镉汞红外焦平面探测器的性能,因此对表面钝化提出了更高的要求。文中通过研究磁控溅射生长的钝化层进行三温段退火改善长波器件性能,实验结果表明低温段(120~170℃)退火显著改善膜层的致密性,二次离子质谱(Secondary ion mass spectroscopy)表明高温段(320℃/2.5 h)退火高组分层厚度达到0.22μm,改善器件的表面漏电流;第三段低温(200~270℃)稳定载流子浓度在1.0×10^(16)~3.0×10^(16) cm^(-3)范围内。三温段退火工艺提高了钝化膜层的致密性、增大了碲镉汞界面的高组分过渡层厚度的同时稳定了碲镉汞材料的电学参数,为长波碲镉汞红外器件的发展奠定了基础。展开更多
We introduce a novel method to create mid-infrared(MIR)thermal emitters using fully epitaxial,metal-free structures.Through the strategic use of epsilon-near-zero(ENZ)thin films in InAs layers,we achieve a narrow-band...We introduce a novel method to create mid-infrared(MIR)thermal emitters using fully epitaxial,metal-free structures.Through the strategic use of epsilon-near-zero(ENZ)thin films in InAs layers,we achieve a narrow-band,wide-angle,and p-polarized thermal emission spectra.This approach,employing molecular beam epitaxy,circumvents the complexities associated with current layered structures and yields temperature-resistant emission wavelengths.Our findings contribute a promising route towards simpler,more efficient MIR optoelectronic devices.展开更多
A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a...A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.展开更多
介绍了宽视场长波红外(LWIR)光学系统技术指标。离轴三反射镜消像散(TMA)型光学系统光谱覆盖范围宽,可提供一个空间分辨率高、观测范围大的无遮挡视场,能够在 F 数相对较小的光学系统中实现接近衍射极限的光学性能。TMA 型光学系统能满...介绍了宽视场长波红外(LWIR)光学系统技术指标。离轴三反射镜消像散(TMA)型光学系统光谱覆盖范围宽,可提供一个空间分辨率高、观测范围大的无遮挡视场,能够在 F 数相对较小的光学系统中实现接近衍射极限的光学性能。TMA 型光学系统能满足推扫式 LWIR 扫描仪所要求光学系统大观测视场、高光学效率等指标,可作为预先研究星载遥感仪的光学结构。展开更多
依据光学被动消热差理论，利用硫系玻璃的热稳定性、长波红外透过特性等优点，对长波非制冷双视场光学系统进行了无热化研究，设计了一个大相对孔径、3倍变焦的双视场长波红外光学系统。其具体参数为：F/#为1，焦距为50/150 mm，总长240...依据光学被动消热差理论，利用硫系玻璃的热稳定性、长波红外透过特性等优点，对长波非制冷双视场光学系统进行了无热化研究，设计了一个大相对孔径、3倍变焦的双视场长波红外光学系统。其具体参数为：F/#为1，焦距为50/150 mm，总长240 mm ，采用640×480的焦平面探测器，像元大小为17μm×17μm，工作波段8~12μm，系统使用了三种长波红外材料：Ge、ZnS、IRG201。在-40~60℃下，其长短焦处像质均接近衍射极限。展开更多
文摘为提高长波红外偏振成像系统中偏振器件性能,本文通过分析光栅材料及结构参数对光栅偏振性能的影响,设计并优化了一种双层材料构成的亚波长光栅。该光栅为矩形形貌,光栅区由铝与硒化锌构成,两种材料的厚度分别为0.6μm和0.4μm,光栅周期1μm,占空比50%。利用严格耦合波理论分析并计算该结构光栅的衍射效率,7~15μm波段的光以0~60°入射后其0级横磁模透射率达到87.54%以上,消光比超过47 d B。该光栅在10.6μm的测试波长下,TM透射率高达90.80%且具有50 d B以上的消光比,相比槽深相同的单层铝光栅,偏振透过率明显提高。仿真结果显示,该光栅在整个宽长波红外波段具有良好的偏振性能。
文摘Pixel-wise Code Exposure (PCE) camera is one type of compressive sensing camera that has low power consumption and high compression ratio. Moreover, a PCE camera can control individual pixel exposure time that can enable high dynamic range. Conventional approaches of using PCE camera involve a time consuming and lossy process to reconstruct the original frames and then use those frames for target tracking and classification. In this paper, we present a deep learning approach that directly performs target tracking and classification in the compressive measurement domain without any frame reconstruction. Our approach has two parts: tracking and classification. The tracking has been done using YOLO (You Only Look Once) and the classification is achieved using Residual Network (ResNet). Extensive experiments using mid-wave infrared (MWIR) and long-wave infrared (LWIR) videos demonstrated the efficacy of our proposed approach.
文摘This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.
文摘随着碲镉汞(HgCdTe)红外探测器的不断发展,碲镉汞波长已经逐渐从中波向长波/甚长波方向发展,表面效应很大程度上决定了碲镉汞红外焦平面探测器的性能,因此对表面钝化提出了更高的要求。文中通过研究磁控溅射生长的钝化层进行三温段退火改善长波器件性能,实验结果表明低温段(120~170℃)退火显著改善膜层的致密性,二次离子质谱(Secondary ion mass spectroscopy)表明高温段(320℃/2.5 h)退火高组分层厚度达到0.22μm,改善器件的表面漏电流;第三段低温(200~270℃)稳定载流子浓度在1.0×10^(16)~3.0×10^(16) cm^(-3)范围内。三温段退火工艺提高了钝化膜层的致密性、增大了碲镉汞界面的高组分过渡层厚度的同时稳定了碲镉汞材料的电学参数,为长波碲镉汞红外器件的发展奠定了基础。
文摘We introduce a novel method to create mid-infrared(MIR)thermal emitters using fully epitaxial,metal-free structures.Through the strategic use of epsilon-near-zero(ENZ)thin films in InAs layers,we achieve a narrow-band,wide-angle,and p-polarized thermal emission spectra.This approach,employing molecular beam epitaxy,circumvents the complexities associated with current layered structures and yields temperature-resistant emission wavelengths.Our findings contribute a promising route towards simpler,more efficient MIR optoelectronic devices.
文摘A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.
文摘依据光学被动消热差理论，利用硫系玻璃的热稳定性、长波红外透过特性等优点，对长波非制冷双视场光学系统进行了无热化研究，设计了一个大相对孔径、3倍变焦的双视场长波红外光学系统。其具体参数为：F/#为1，焦距为50/150 mm，总长240 mm ，采用640×480的焦平面探测器，像元大小为17μm×17μm，工作波段8~12μm，系统使用了三种长波红外材料：Ge、ZnS、IRG201。在-40~60℃下，其长短焦处像质均接近衍射极限。
