Optical Vernier sampling using a dual-comb-swept laser to solve distance aliasing  

作　　者：SEONGJIN BAK GYEONG HUN KIM HANSOL JANG CHANG-SEOK KIM 

机构地区：[1]Department of Cogno-Mechatronics Engineering,Pusan National University,Busan 46241,Republic of Korea

出　　处：《Photonics Research》2021年第5期657-667,共11页光子学研究（英文版）

基　　金：Korea Medical Device Development Fund grant funded by the Korea government(the Ministry of Science and ICT,the Ministry of Trade,Industry and Energy,the Ministry of Health and Welfare,the Ministry of Food and Drug Safety)(202011C13,KMDF_PR_20200901_0055);Commercialization Promotion Agency for R&D Outcomes(COMPA)funded by the Ministry of Science and ICT(1711123345);Korea Institute for Advancement of Technology(KIAT)grant funded by the Ministry of Trade,Industry and Energy(N0002310)。

摘　　要：Optical interferometry using comb-swept lasers has the advantage of efficiently reducing the acquisition bandwidth for high-speed and long-range detection. However, in general, the use of a comb-swept laser involves a critical limitation in that the absolute distance cannot be measured, and, thus, multiple layers cannot be distinguished when measuring each position. This is because of the distance ambiguity induced by optical aliasing, in which there is periodic repetition of the frequency of an interferometric signal owing to discrete spectral sweeping, which does not occur in conventional optical interferometry that uses a continuous swept laser. In this paper, we introduce an optical Vernier sampling method using a dual-comb-swept laser to measure the absolute distances in a multi-layer target. For this, we designed a new type of dual-comb-swept laser to include two different free spectral ranges(FSRs) in separated wavelength bands to provide a stable lasing condition. Using a principle similar to that of a Vernier caliper for length measurement, the two different FSRs can be used to recover a higher frequency of an optical interferometric signal to measure longer distances from different layers in a target.Using the dual-comb-swept laser in optical interferometry, we solved the optical aliasing issue and measured the absolute distances of three layers separated over 83 mm using a point-scanning imaging setup and the simultaneous absolute distance of the top surfaces separated over 45 mm using a full-field imaging setup at14 and 8 times lower acquisition bandwidth than a conventional continuous swept laser that is based on optical interferometry.

关 键 词：laser INTERFEROMETRY ABSOLUTE 

分 类 号：TN248[电子电信—物理电子学]