摘要
多波长光源照射下微弱光的准确检测是利用近红外漫射光进行人体疾病诊断时所面临的基本问题,而多光源并行检测是实现快速测量所要解决的关键问题之一.基于数字锁相的基本原理,提出了结合单光子计数技术和现场可编程门阵列(FPGA)平台的多通道数字锁相方案,不但可实现微弱光的准确检测,而且可实现多通道实时并行检测.基于此方案,搭建了多通道近红外光检测系统.实验结果表明,所搭建的检测系统对由仿体出射光的检测信噪比为24 dB,同时对不同频率编码的光源具有很好的识别度,对不同调制幅度的测量误差小于9.13%.
The accurate detection of weak light caused by multiple light sources is a fundamental problem in the domain of human disease diagnosis using near infrared（NIR） light.In addition,parallel detection under multiple sources serves as an effective way for real-time fast measurement.Based on the principle of digital lock-in detection,a multichannel digital lock-in scheme on an FPGA platform using single photon counting technique was proposed in this paper,which could achieve not only accurate detection of weak light but also real-time parallel detection under multiple sources.A multichannel NIR light detection system was also developed.Experimental results show that the signal-to-noise ratio of the established system when applied to detect the diffused light emitted from phantom can reach 24 dB,and at the same time,the detection system has a good identification of different sources modulated at different frequencies.For light sources modulated in different modulation amplitudes,the measurement error is less than 9.13%.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2011年第3期228-233,共6页
Nanotechnology and Precision Engineering
基金
国家高技术研究发展计划(863计划)资助项目(2009AA02Z413)
国家自然科学基金资助项目(30870657
30970775)
天津市重点基金资助项目(09JCZDJC18200)
关键词
数字锁相检测
单光子计数
频分复用技术
近红外光检测
digital lock-in detection
single photon counting
frequency division multiplexing
near infrared light detection
