Deep-subwavelength all-dielectric composite materials are believed to tightly obey the Maxwell Garnett effective medium theory. Here, we demonstrate that the Maxwell Garnett theory could break down due to evanescent fields in deep-subwavelength dielectric
为仿真现实场景中目标和干扰的光谱分布差异, 设计了一种基于双数字微镜器件(DMD,Digital Micro-mirror Device)的双通道、共口径、变焦光学引擎, 包括投影光学系统和两套照明光学系统.光学引擎以红外中波和长波柯勒远心光路分别直接照明两DMD靶面, 采用空间立体布局避免不同光路间干扰.设计结果表明: 照明光学系统的照度均匀性优于94%; 中波(3.7~4.8 μm)和长波(8~12 μm)内, 变焦投影光学系统在10 1p/mm处的调制传递函数(MTF, Modulation Tra
Fluorescence analysis applied in the study of lactic acid bacteria (LAB) provides a new method and theory to study probiotics and realize the detection and identification of the strains. It is also possible to achieve automation and computerization. In th
发展适用于低光子数应用环境的荧光寿命分析方法对快速荧光寿命显微成像(FLIM)方法的发展和应用都具有重要意义。受高密度单分子定位显微成像中压缩感知算法的启发,将荧光寿命分析看成一个稀疏逆问题,提出了一种基于交替下降条件梯度(ADCG)的荧光寿命分析新方法,并通过对模拟数据和实验数据进行分析,验证了ADCG-FLIM算法即使在低光子数情形下依然能够较好地分析荧光寿命,从而有利于活细胞快速FLIM技术的发展和应用。
针对化学方法会破坏指纹样本的问题,提出了一种紫外成像的光学方法。基于氨基酸和尿素的相对浓度关系以及散射光谱曲线理论,推导了指纹在不同紫外波段的辐亮度比值与时间关系的数学模型。搭建了一套紫外多光谱成像设备,在3个紫外波段对指纹进行了无损提取。对不同波段指纹图像的DN值进行反演分析,得到了不同波段的DN值之比与指纹遗留时间之间的关系。实验结果表明:各紫外波段的DN值之比仅与时间有关,与指纹个体差异无关。指纹老化曲线拟合的表达式与推导的数学模型一致,验证了紫外多光谱成像对指纹遗留时间评估的可行性,为无损指纹测龄
Laser absorption spectroscopy (LAS) has become the most widely used laser spectroscopic technique for gas detection due to its capability of accurate quantification and straightforward operation. However, since resolving weak absorption and averting over-
A diode-end-pumped tunable twisted-mode cavity Tm, Ho:YAG laser with single-longitudinal-mode (SLM) operation is demonstrated in this Letter. The maximal SLM output power is 106 mW with a slope efficiency of 4.86%. The wavelength can be changed from 2090.
In order to reveal the evolution mechanism of repaired morphology and the material’s migration mechanism on the crack surface in the process of