Riza Nabeel A, La Torre J Pablo
Opt Express. 2016 Dec 26;24(26):29427-29443. doi: 10.1364/OE.24.029427.
For the first time, proposed and demonstrated is a simultaneous dual optical band coded access optical sensor (CAOS) camera design suited for extreme contrast multispectral bright target scenarios. Deploying a digital micromirror devices (DMDs)-based time-frequency agile pixels CAOS-mode within a two point detector spatially and spectrally isolating framework, this imager simultaneously and independently detects pixel selective image information for two different broad spectral bands that further undergo independent spectral image data extraction via finer-tuned wavelength filtering using all-optical or CAOS-mode electronic filters. A proof-of-concept visible-near infrared band CAOS imager is successfully demonstrated using a target scene containing LEDs and engaging narrowband optical filters. In addition, using the CAOS-mode, demonstrated is the RF domain simultaneous color content monitoring of a white light LED image pixel. Also proposed is the use of a higher bit count analog-to-digital converter (ADC) with both range and sampling duration parameter control along with a larger data set electronic DSP to extract higher DSP gain and realize additional noise suppression. Using a 16-bit ADC and 2,097,152 point fast Fourier transform (FFT) digital signal processing (DSP) for a 633 nm laser engaged test target scene that is subject to nearly 7 decades (10) of gradual optical attenuation, the experimental camera demonstrates an agile pixel extreme dynamic range of 136 dB, which is a 56 dB improvement over the previous CAOS-imaging demonstrations.
首次提出并演示了一种适用于极端对比度多光谱亮目标场景的同时双光带编码访问光学传感器(CAOS)相机设计。在两点探测器的空间和光谱隔离框架内部署基于数字微镜器件(DMD)的时频灵活像素CAOS模式,该成像仪同时独立地检测两个不同宽光谱带的像素选择性图像信息,这些信息通过使用全光或CAOS模式电子滤波器进行微调波长滤波进一步进行独立的光谱图像数据提取。使用包含发光二极管(LED)的目标场景和窄带光学滤波器,成功演示了概念验证可见 - 近红外波段CAOS成像仪。此外,使用CAOS模式,演示了对白光LED图像像素的射频域同时颜色内容监测。还提出使用具有范围和采样持续时间参数控制的更高位数模数转换器(ADC)以及更大数据集的电子数字信号处理器(DSP)来提取更高的DSP增益并实现额外的噪声抑制。对于一个经历了近7个数量级(10)逐渐光衰减的633nm激光参与的测试目标场景,使用16位ADC和2,097,152点快速傅里叶变换(FFT)数字信号处理(DSP),实验相机展示了136dB的灵活像素极端动态范围,这比之前的CAOS成像演示提高了56dB。