基于等倾干涉原理和CMOS图像传感技术的流体折射率微变传感系统

Sensing System for the Micro-Change of Refractive Index of Fluid Based on Equal Inclination Interference Principle and CMOS Image Sensing Technique

基于等腰劈光学等倾干涉原理,利用CMOS(complementary metal oxide semiconductor,互补金属氧化物半导体)图像传感器,设计了一种可测量流体折射率微小变化的传感器系统。该系统使用具有高频率像素时钟的CMOS图像传感器对等腰劈中出射光信号进行测量,将携带信息的光信号转换成电信号,再经过一块现场可编程门阵列(field programmable gate array,FPGA)芯片采集数字图像,通过极值计数法处理数据获得光学信息,从而计算流体折射率微变量。该传感器系统的理论测量精度达2.75×10^-6,可应用于大气测量和材料研究等领域。

Based on the equal inclination interference in an isosceles triangular wedge,a sensing system that can measure the micro-change of the refractive index of the fluid is designed by using CMOS(complementary metal oxide semiconductor)image sensor.The system uses a high-frequency pixel clock CMOS image sensor to measure the outgoing light signal from the isosceles triangular wedge,converts the optical signal carrying information into an electrical signal,collects digital images through a field programmable gate array(FPGA)chip,and obtains optical information by processing data through extreme value counting,there⁃by calculating the micro-change of the refractive index of fluid.The theoretical measurement accuracy of the sensing system can reach 2.75×10^-6,which can be applied to fields of atmospheric measurement and materials research.