激光技术2016，Vol.40Issue(4)：496-499,4.DOI:10.7510/jgjs.issn.1001-3806.2016.04.009
基于光子混频连续太赫兹波的厚度检测
Thickness measurement by means of continuous wave terahertz based on photomixing
摘要
Abstract
In order to measure thickness of a specimen with a continuous wave terahertz imaging system based on photomixing, its 2-D thickness was measured by means of the phase information obtained from the imaging system. A continuous wave terahertz imaging system based on photomixing was established by using two external cavity laser diodes. The specimen was placed on the X-Y motorized precision translation stage and point-to-point scanning images were generated. Both the amplitude and phase information can be obtained simultaneously through the system. The signal-to-noise ratio of the system was 68dB at the frequency of 0. 47THz. The deviation between the calculated result and the actual measurement was less than 0. 02mm. The influences of the interference of plane specimen and transmission intensity on thickness measurement accuracy were analyzed. The results show that, the higher refractive index of the plane specimen is, the greater interference influence on thickness measurement becomes. The accuracy increases with the increase of terahertz transmission. The accuracy of thickness is better than 2. 0% when the transmission coefficient is higher than 0. 5.关键词
测量与计量/厚度测量/相位信息/光子混频/连续太赫兹波成像Key words
measurement and metrology/thickness measurement/phase information/photomixing/continuous wave terahertz imaging分类
电子信息工程引用本文复制引用
刘子烨,刘建军,洪治..基于光子混频连续太赫兹波的厚度检测[J].激光技术,2016,40(4):496-499,4.基金项目
国家自然科学基金资助项目(60576042 （）
61377108) （）
