In this paper, we propose the sinusoidal frequency modulation on a laser diode (LD) to achieve both frequency stabilization of the LD and displacement measurement with a homodyne interferometer. The central frequency of the LD is stabilized to a Doppler broadened absorption line of an iodine (I2) molecule near the wavelength of 633 nm. The frequency of the LD is modulated across the absorption line and synchronous detection is utilized to detect the absorption signal. A simple and low-cost homodyne displacement-measuring interferometer can be constructed that can attain high measurement resolution.

Date Published: 24 September 2015
PDF: 9 pages
Proc. SPIE 9628, Optical Systems Design 2015: Optical Fabrication, Testing, and Metrology V, 96281D (24 September 2015); doi: 10.1117/12.2191032

Published in SPIE Proceedings Vol. 9628:
Optical Systems Design 2015: Optical Fabrication, Testing, and Metrology V
Angela Duparré; Roland Geyl, Editor(s)