[OPTICAL REVIEW Vol. 17, No. 3 (2010) 171-175]
© 2010 The Japan Society of Applied Physics

Measurement Technique for Depth Profiling in Time-Domain Low-Coherence Interferometer

Ribun ONODERA1*, Shuhei OSHIDA1,2, and Yukihiro ISHII3

1Department of Electronics, University of Industrial Technology, 4-1-1 Hashimotodai, Sagamihara, Kanagawa 229-1196, Japan
2Tokyo Seimitsu Co., Ltd., 2968-2 Ishikawa-machi, Hachioji, Tokyo 192-0032, Japan
3Department of Applied Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan

(Received September 25, 2009; Accepted January 5, 2010)

A measurement technique for depth profiling in a time-domain low-coherence interferometer has been proposed. The spatial variation of the optical path caused by a diffraction grating in the Littrow configuration produces a white-light interferogram. A one-dimensional charge-coupled device (1D-CCD) detector is used to measure the undersampled white-light interferogram. The position of the reflective boundary is calculated from the rate of phase change with spatial frequency, which is based on the sub-Nyquist sampling of the white-light interferogram in the frequency domain.

Key words: low-coherence interferometer

*E-mail address: onodera@uitec.ac.jp