Ribun ONODERA^1,*, Hiroto WATANABE^1,2 and Yukihiro ISHII¹

¹Department of Electronics, University of Industrial Technology, 4-1-1 Hashimotodai, Sagamihara, Kanagawa 229-1196, Japan
²Imaging Laboratory R & D Center, TOPCON Corporation, 75-1 Hasunuma-cho, Itabashi-ku, Tokyo 174-8580, Japan

(Received July 5, 2004; Accepted November 22, 2004)

A phase-demodulation scheme using a discrete Hilbert transform that can change the interferometric phase by π/2 has been investigated. In-quadrature components of a fringe pattern are obtained from one captured interferogram using a one-dimensional (1-D) discrete Hilbert transform and a 1-D discrete high-pass filtering that are based on a digital signal processing technique. The phase distribution in the range of 15π (rad) can be demodulated with the proposed method. The 1-D discrete Hilbert transform can be extended to two-dimensional calculation with a raster scanning procedure.

Key words: phase measurement, optical interferometry

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