Study of interferometric phase modulation method for increasing measurement speed of optical coherence microscopy

• Main Author: 陳逸穎
• Other Authors: 盧聖華
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/76979939466987299563

碩士 === 逢甲大學 === 光電學系 === 103 === This study presents an optical coherence microscope (OCM) using achromatic sinusoidal phase modulation and four integrating buckets method to increase measurement speed. The optical phase of the reference beam was modulated by a frequency domain optical delay line (FDODL) driven with a sinusoidal voltage at 50 Hz. The periodic time-varying interferogram formed by the interference of reference and measurement beams was recorded by a 200-Hz digital camera. We captured four sequential frames in a modulation period and the exposure time of each frame was one quarter period. The cross-sectional amplitude/phase map of a sample was calculated from these four frames with four integrating buckets algorithm. The speed of the proposed OCM system was 2.5 times faster than that using stepping phase shift interferometry. Additionally, using FDODL phase modulator can effectively suppress parasitic fringes and reduce phase errors.