基于虚拟锁相技术的原位光学测量技术研究

本文构建了一套基于虚拟锁相放大技术的、能准确测量微弱信号的高精度宽波段原位光学测量系统。介绍了该测量系统的建立目的，系统结构及原理；阐述了如何通过美国Ni公司的图形化编程语言Labview来虚拟实现锁相放大器功能，并应用于本套测量系统。这样既降低了成本，又简化了系统结构。测量了系统光源在200-2500nm的光强分布，测量了系统紫外可见部分及红外部分测量重复性，分别能达到0.12％、0.54％。最后利用该套系统测量了一块石英玻璃的透过率,并与lambda950的测量结果比较，两者测量结果平均相差0.95%。实验结果表明，使用了虚拟技术来实现锁相放大处理的该套原位光学测量系统的测量精度较高，对杂光和电气设备带来的噪声的抑制能力较强，能有效得对样品进行原位光学性能测量。

The research of original position optic measuring technique based on virtual Lock-in

In order to measure the changes of optic characteristics for spacial materials before and after space radiation,a in situ optic measuring system with high precision and wide scanning wavelength was designed to measure feeble signal accurately buried in noise based on a virtual lock-in technique.The system structure,and measuring principle were introduced.Then,the G language Labview was used to develop a program to implement the virtual lock-in technique,and apply it in the system.After that,the light source intensity distribution and the system measuring repetitiveness were measured.Finally,proposed system was used to measure the transparence of a quartz glass.Compared with that of lambda950,the measured results show that the mean error between them is 0.95%.The experimental results indicate that the virtual lock-in technique not only restrains effectively the noise brought by interferential light and electronic equipment,but also simplifies the system structure;This in-situ measuring system by using such technique can accurately measure optic characteristics of spacial materials.