In this investigation, we propose a multi-channel optical sensor to be used for precision industry to measure small gaps of a target or motion errors of a moving stage. The sensor consists of optical fiber components such as a CWDM and fiber probes for compactness, reliability and easy use. The operating principle of the sensor is based on the spectrally-resolved interferometry, where the spectral interferogram using a broadband light source is detected by a spectrometer. Each channel possesses its own spectrum as a result of spectral filtering of a CWDM and measures the distance independently. This optical sensor does not need any mechanical or electrical moving parts it can realize real-time measurements. In this presentation, we show the operating principle of the multi-channel optical gap sensor, its optical configuration and the experimental results.

Date Published: 1 July 2015
PDF: 4 pages
Proc. SPIE 9655, Fifth Asia-Pacific Optical Sensors Conference, 965502 (1 July 2015); doi: 10.1117/12.2183997

Published in SPIE Proceedings Vol. 9655:
Fifth Asia-Pacific Optical Sensors Conference
Byoungho Lee; Sang-Bae Lee; Yunjiang Rao, Editor(s)