[OPTICAL REVIEW Vol. 18, No. 1 (2011) 103-106]
© 2011 The Japan Society of Applied Physics

Quadrature Phase-shifting Interferometer Using Spatial Carrier

Tomohiro KIIRE*, Suezou NAKADATE1, Masato SHIBUYA1, and Toyohiko YATAGAI

Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya 321-8585, Japan
1Department of Media and Image Technology, Faculty of Engineering, Tokyo Polytechnic University, Atsugi, Kanagawa 243-0297, Japan

(Received June 10, 2010; Accepted September 9, 2010)

We propose a high-speed phase measurement using a phase calculation algorithm in a quadrature phase-shifting interferometer (QPI), which is applied to tilted fringes. Although the spatial carrier method is useful for a high-speed measurement with a single imaging sensor, the spatial resolution in conventional phase calculation algorithms is reduced owing to the use of three or more phase-shifted data at different sample points. Phases in the QPI method can be calculated with only two quadarture phase-shifted data extracted from the tilted fringes before and after a phase change of the interferometer. Thus, the proposed method can suppress the reduction of the spatial resolution compared with that in conventional methods, and makes it possible to measure a phase at high-speed. The principle and experimental results of this technique are presented.

Key words: interferometer, spatial carrier, phase shift, phase calculation, resolution

*E-mail address: kiire@cc.utsunomiya-u.ac.jp