[OPTICAL REVIEW Vol. 10, No. 5 (2003) 456-461]
© 2003 The Optical Society of Japan

New Phase-Shifting Method Using Two Images

Manabu SATO1, Jun IWASAKI1, Toshiaki OHOTAKI1, Yukihiro HASHIMOTO1 and Naohiro TANNO1,2

1Yamagata University, Yonezawa City, Yamagata 992-8510, Japan
2Japan Science and Technology Corporation, Regional Joint Research Project of Yamagata Prefecture, 2-2-1 Matsuei, Yamagata 990-2473, Japan

(Received February 12, 2003; Accepted April 8, 2003)

We propose a continuous two-step method (CTSM) to obtain an image from two interference images for the measurement time reduction of optical coherence tomography. Image processing is performed for each pixel in CTSM. The calculated signal intensity has an average and standard deviation after processing since the heterodyne beat signal contains the noise in the measurements. We assume that the heterodyne beat signal contains the random noise in simulations and calculate the influence of the normalized standard deviation (NSD = standard deviation/average) on the random noise intensity for both CTSM and the conventional three-step method (TSM). We found that the NSD of the CTSM is only 1.4 times greater than that of the TSM despite processing only two images.

Key words: optical coherence tomography, phase-shifting interferometry, two-step method