Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of br...Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of broadband NIR phosphor-converted light emitting diode(pc-LED).However,the purposeful design of a tunable ultra-broadband NIR-emitting phosphor in a single host is still a challenge.In this work,Ga_(2)GeO_(5) with two sites of six-coordinated[Ga1O_(6)]and five-coordinated[Ga2O_(5)]is chosen to host Cr^(3+),successfully producing tunable broadband NIR luminescence(680-1350 nm).It can be tuned largely from 828 to 970 nm with the full-width at half maximum(FWHM)varied from 208 to 258 nm just by simply adjusting the Cr^(3+)-doping content.The tailoring of the Cr^(3+)NIR spectral emission is ascertained to the site occupation preference and competition.The encapsulation of a prototype of NIR pc-LED with an output power of 29.5mW@390 mA is conducted for the implementation of night-vision application.This work provides a novel broadband NIR phosphor by Cr^(3+)-doping in both the sixand five-coordination field,meanwhile,further demonstrating the feasibility of discovering new host material with more than one crystallographic site for Cr^(3+)to trigger tunable broadband NIR emission.展开更多
For better night-vision applications using the low-light-level visible and infrared imaging, a fusion framework for night-vision context enhancement（FNCE） method is proposed. An adaptive brightness stretching method...For better night-vision applications using the low-light-level visible and infrared imaging, a fusion framework for night-vision context enhancement（FNCE） method is proposed. An adaptive brightness stretching method is first proposed for enhancing the visible image. Then, a hybrid multi-scale decomposition with edge-preserving filtering is proposed to decompose the source images. Finally, the fused result is obtained via a combination of the decomposed images in three different rules. Experimental results demonstrate that the FNCE method has better performance on the details（edges）, the contrast, the sharpness, and the human visual perception. Therefore,better results for the night-vision context enhancement can be achieved.展开更多
描述了一种判断夜视仪用微光像增强器性能梯次的方法,基于视距模型对影响探测能力因素进行了分析,研究了积分灵敏度、极限分辨力特性测试条件与实际夜视环境的差异,分析了夜天光辐射光谱特性、大气传输的光谱衰减特性、背景反射特性的...描述了一种判断夜视仪用微光像增强器性能梯次的方法,基于视距模型对影响探测能力因素进行了分析,研究了积分灵敏度、极限分辨力特性测试条件与实际夜视环境的差异,分析了夜天光辐射光谱特性、大气传输的光谱衰减特性、背景反射特性的光谱差异以及光阴极响应光谱特性对视距的影响,梳理了传统上以极限探测性能来判断像增强器优劣方法的不足,提出了“能力因数”模型,包含信噪比、低照度及低对比度下分辨力参数和技术特征因素,采用该方法对像增强器两大技术路线(砷化镓器件、多碱器件)进行梯次和代际分析,设计了三代像增强器发展路线。结果表明,“能力因数”模型(Figure of Capability,FOC)能够准确反映像增强器技术路线和性能梯次发展规律。展开更多
基金financially supported by the National Natural Science Foundation of China (No.51802045)Guangzhou basic and applied basic research project (No.202102020871)。
文摘Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of broadband NIR phosphor-converted light emitting diode(pc-LED).However,the purposeful design of a tunable ultra-broadband NIR-emitting phosphor in a single host is still a challenge.In this work,Ga_(2)GeO_(5) with two sites of six-coordinated[Ga1O_(6)]and five-coordinated[Ga2O_(5)]is chosen to host Cr^(3+),successfully producing tunable broadband NIR luminescence(680-1350 nm).It can be tuned largely from 828 to 970 nm with the full-width at half maximum(FWHM)varied from 208 to 258 nm just by simply adjusting the Cr^(3+)-doping content.The tailoring of the Cr^(3+)NIR spectral emission is ascertained to the site occupation preference and competition.The encapsulation of a prototype of NIR pc-LED with an output power of 29.5mW@390 mA is conducted for the implementation of night-vision application.This work provides a novel broadband NIR phosphor by Cr^(3+)-doping in both the sixand five-coordination field,meanwhile,further demonstrating the feasibility of discovering new host material with more than one crystallographic site for Cr^(3+)to trigger tunable broadband NIR emission.
基金supported by the National Natural Science Foundation of China(No.61231014)the Foundation of Army Armaments Department of China(No.6140414050327)the Foundation of Science and Technology on Low-Light-Level Night Vision Laboratory(No.BJ2017001)
文摘For better night-vision applications using the low-light-level visible and infrared imaging, a fusion framework for night-vision context enhancement（FNCE） method is proposed. An adaptive brightness stretching method is first proposed for enhancing the visible image. Then, a hybrid multi-scale decomposition with edge-preserving filtering is proposed to decompose the source images. Finally, the fused result is obtained via a combination of the decomposed images in three different rules. Experimental results demonstrate that the FNCE method has better performance on the details（edges）, the contrast, the sharpness, and the human visual perception. Therefore,better results for the night-vision context enhancement can be achieved.
文摘描述了一种判断夜视仪用微光像增强器性能梯次的方法,基于视距模型对影响探测能力因素进行了分析,研究了积分灵敏度、极限分辨力特性测试条件与实际夜视环境的差异,分析了夜天光辐射光谱特性、大气传输的光谱衰减特性、背景反射特性的光谱差异以及光阴极响应光谱特性对视距的影响,梳理了传统上以极限探测性能来判断像增强器优劣方法的不足,提出了“能力因数”模型,包含信噪比、低照度及低对比度下分辨力参数和技术特征因素,采用该方法对像增强器两大技术路线(砷化镓器件、多碱器件)进行梯次和代际分析,设计了三代像增强器发展路线。结果表明,“能力因数”模型(Figure of Capability,FOC)能够准确反映像增强器技术路线和性能梯次发展规律。
