A digital phase-measuring interferometer with a laser-diode source has been developed that is based on a fringe-scanning technique with a stepwise wavelength change by variation of the laser injection current. The phase is changed to produce a relative phase difference between the beams in the two arms of the interferometer. Calibrated phase shifts used for a phase-extraction algorithm are derived from one-dimensional least-squares fits to cosine fringe functions to achieve accurate results. Experimental results are presented.
© 1987 Optical Society of America
Original Manuscript: October 8, 1986
Manuscript Accepted: January 12, 1987
Published: April 1, 1987
Yukihiro Ishii, Jun Chen, and Kazumi Murata, "Digital phase-measuring interferometry with a tunable laser diode," Opt. Lett. 12, 233-235 (1987)