A phase-shift-locked interferometer has been constructed for distance measurement. A phase shift produced by sawtooth-current modulation of a laser diode is locked to a phase difference preset by polarization optics that consists of a quarter-wave plate and polarizers through an electrical feedback technique. An optical path difference can be measured from the locked sawtooth-wave current amplitude in real time. The sensitivity of the interferometer is discussed.
© 2003 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4820) Instrumentation, measurement, and metrology : Optical systems
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(140.2020) Lasers and laser optics : Diode lasers
Ribun Onodera and Yukihiro Ishii, "Phase-Shift-Locked Interferometer with a Wavelength-Modulated Laser Diode," Appl. Opt. 42, 91-96 (2003)