MINIATURE LASER VIBROMETER SYSTEM WITH MULTIFUNCTION INTEGRATED OPTIC CIRCUIT

A miniature laser vibrometer system (LVS) is demonstrated which uses a proton-exchanged LiNbO3 multifunction integrated optic circuit for signal processing. The system uses a pigtailed 0.83 pm laser diode as the source and common-path interferometry to provide a phase-insensitive fiber-optic probe for monitoring moving or vibrating parts. The LVS provides 55 dB signal-to-noise ratio for 3 kHz bandwidth, even when monitoring parts with relatively low (1 percent) reflectivity. The optical components and all electronics are housed in an 11.5 × 10.5 × 4.2 cm package which operates from a ± 15 V, 300 mA supply. © 1990 IEEE