We propose a sinusoidal phase modulating laser diode interferometer which is insensitivity to vibrations of optical devices and fluctuations in the optical wavelength of the laser diode. We analyze the sinusoidal phase modulation in a laser diode interferometer, and describe the principle of the feedback control of the injection current of the laser diode to eliminate the fluctuations in the phase of the interference signal caused by external disturbances. We construct two sinusoidal phase modulating interferometers for movement measurements and surface profile measurements, respectively. The experimental results make it clear that the interferometers can be used in mechanically noisy circumstances.

Date Published: 20 November 1989
PDF: 8 pages
Proc. SPIE 1163, Fringe Pattern Analysis, (20 November 1989); doi: 10.1117/12.962776

Published in SPIE Proceedings Vol. 1163:
Fringe Pattern Analysis
Graeme T. Reid, Editor(s)