针对天基短波红外图像中弱小目标易被云层、地表杂波淹没,且在低信杂比条件下检测困难的问题,提出一种融合安德森加速的自正则化加权稀疏模型(Self-Regularized Weighted Sparse,SRWS)与相对局部对比度(Relative Local Contrast Measure...针对天基短波红外图像中弱小目标易被云层、地表杂波淹没,且在低信杂比条件下检测困难的问题,提出一种融合安德森加速的自正则化加权稀疏模型(Self-Regularized Weighted Sparse,SRWS)与相对局部对比度(Relative Local Contrast Measure,RLCM)的改进检测方法。通过引入安德森加速机制,显著降低了背景估计的计算复杂度,利用背景残差图和RLCM实现了多尺度目标检测性。实验结果表明,本文算法在复杂背景下仍保持优异性能,接收者操作曲线下面积(Area Under Curve,AUC)最高达0.950,最低不低于0.842;信杂比增益(Signal-to-Clutter Ratio Gain,SCRG)显著优于红外图像块(Infrared Patch Image,IPI)、局部对比度法(Local Contrast Measure,LCM)等传统方法。本研究有效提升了天基短波红外弱小目标的检测精度与稳定性,为复杂背景下的遥感目标检测提供了可靠的解决方案。展开更多
碲镉汞短波红外焦平面探测器在红外天文观测中具有重要作用。采用光子转移曲线(Photon Transfer Curve, PTC)来表征探测器性能参数是一种重要的测试方法。根据PTC测量探测器的增益是表征探测器其他性能的前提。采用碲镉汞液相外延薄膜...碲镉汞短波红外焦平面探测器在红外天文观测中具有重要作用。采用光子转移曲线(Photon Transfer Curve, PTC)来表征探测器性能参数是一种重要的测试方法。根据PTC测量探测器的增益是表征探测器其他性能的前提。采用碲镉汞液相外延薄膜材料和n-on-p芯片结构制备了640×512规格的红外探测器,探测器截止波长为2.0μm。用PTC方法测量红外焦平面探测器的增益,发现在焦平面上不同区域的增益是不均匀的,增益的非均匀性达到了20.2%。增益的非均匀性反映了探测器芯片内部性能的差异,尤其是不同光敏元噪声的差异。芯片加工过程可能是引起增益不均匀的原因之一。通过改进芯片工艺,特别是改进芯片的机械化学减薄工艺,降低抛光损伤,提高了探测器芯片表面不同区域的增益均匀性。改进工艺后,增益的非均匀性从20.2%降低到0.3%,获得了增益均匀的探测器芯片,增益的平均值为0.159 DN/e-,并测量得到探测器的暗电流为2.2 e-/s,读出噪声为67 e-。展开更多
Tin-lead(Sn-Pb)halide perovskite single crystals combine narrow bandgaps,long carrier diffusion lengths,and low trap densities,positioning them as ideal candidates for near-infrared(NIR)optoelectronics.However,convent...Tin-lead(Sn-Pb)halide perovskite single crystals combine narrow bandgaps,long carrier diffusion lengths,and low trap densities,positioning them as ideal candidates for near-infrared(NIR)optoelectronics.However,conventional growth strategies rely on bulk crystallization at elevated temperatures,leading to uncontrolled nucleation,Sn^(2+)oxidation,and poor compatibility with planar integration.Here,we develop a coordination-engineered crystallization strategy that enables direct,lowtemperature growth of micrometer-thick Sn-Pb single-crystal thin films on device-compatible substrates.By modulating metal-solvent coordination strength using a low-donor number cosolvent system,we delineate a narrow processing window that stabilizes precursor speciation,lowers the nucleation barrier,and guides directional crystal growth under mild thermal conditions(<40℃).The resulting crystal films exhibit smooth morphology,high crystallinity,compositional uniformity,and ultralow trap densities(~3.98×10^(12)cm^(-3)).When integrated into NIR photodetectors,these films deliver high responsivity(0.51 A W^(-1)at 900 nm),specific detectivity up to 3.6×10^(12)Jones,fast response(~188μs),and>25,000 cycles of ambient operational stability.This approach establishes a scalable platform for redox-stable,low-temperature growth of Sn-Pb perovskite crystal films and expands the processing-structure-function landscape for next-generation infrared optoelectronics.展开更多
文摘针对天基短波红外图像中弱小目标易被云层、地表杂波淹没,且在低信杂比条件下检测困难的问题,提出一种融合安德森加速的自正则化加权稀疏模型(Self-Regularized Weighted Sparse,SRWS)与相对局部对比度(Relative Local Contrast Measure,RLCM)的改进检测方法。通过引入安德森加速机制,显著降低了背景估计的计算复杂度,利用背景残差图和RLCM实现了多尺度目标检测性。实验结果表明,本文算法在复杂背景下仍保持优异性能,接收者操作曲线下面积(Area Under Curve,AUC)最高达0.950,最低不低于0.842;信杂比增益(Signal-to-Clutter Ratio Gain,SCRG)显著优于红外图像块(Infrared Patch Image,IPI)、局部对比度法(Local Contrast Measure,LCM)等传统方法。本研究有效提升了天基短波红外弱小目标的检测精度与稳定性,为复杂背景下的遥感目标检测提供了可靠的解决方案。
文摘尽管长波红外成像技术在陆地遥感、天文学等应用中至关重要,但其面临着来自压倒性热背景辐射的根本性挑战。这种背景光子通量常常将传统探测器推向其背景限制性能(Background-Limited Performance,BLIP)的极限。此时主要的限制因素并非探测器固有的噪声,而是背景本身的散粒噪声。本文论证了一个关键的分类,以区分两种表面相似但本质迥异的探测架构——差分探测器和微分探测器。根据探测器的应用和实现途径可知,传统差分探测器的背景光电流为可探测的信号差异设置了一个由背景决定的阈值,而微分探测器则是一种在物理感知层面直接对目标物理量的差异进行测量的器件:只有微弱的差值信号被积分,导致极大量的累加采样,因此可将信噪比提升至前所未有的水平。特别介绍了基于量子阱红外光电探测器(Quantum Well Infrared Photodetector,QWIP)的微分探测技术路径。QWIP以其极低的暗电流、精准的电学可控性和内禀的光谱选择性,为实现高性能长波红外微分探测器提供了理想的物理基础,并已在实验中取得显著进展。最后利用费雪信息理论和克拉默--拉奥约束为微分探测器提供了严格的理论支撑。
基金support received from the National Research Foundation of Korea(NRF)through the Ministry of Science,ICT(Information and Communication Technology),under grant numbers RS-2023-00302646 and RS-2025-02316700.
文摘Tin-lead(Sn-Pb)halide perovskite single crystals combine narrow bandgaps,long carrier diffusion lengths,and low trap densities,positioning them as ideal candidates for near-infrared(NIR)optoelectronics.However,conventional growth strategies rely on bulk crystallization at elevated temperatures,leading to uncontrolled nucleation,Sn^(2+)oxidation,and poor compatibility with planar integration.Here,we develop a coordination-engineered crystallization strategy that enables direct,lowtemperature growth of micrometer-thick Sn-Pb single-crystal thin films on device-compatible substrates.By modulating metal-solvent coordination strength using a low-donor number cosolvent system,we delineate a narrow processing window that stabilizes precursor speciation,lowers the nucleation barrier,and guides directional crystal growth under mild thermal conditions(<40℃).The resulting crystal films exhibit smooth morphology,high crystallinity,compositional uniformity,and ultralow trap densities(~3.98×10^(12)cm^(-3)).When integrated into NIR photodetectors,these films deliver high responsivity(0.51 A W^(-1)at 900 nm),specific detectivity up to 3.6×10^(12)Jones,fast response(~188μs),and>25,000 cycles of ambient operational stability.This approach establishes a scalable platform for redox-stable,low-temperature growth of Sn-Pb perovskite crystal films and expands the processing-structure-function landscape for next-generation infrared optoelectronics.
