Abstract

Recently, there is considerable interest in integration of some waveguide components on a common substrate to achieve a compact and rugged fiber-optic sensor [1]. Among a variety of fiber-optic sensors, the heterodyne-detection optics is very often used for highly accurate measurement of velocity, displacement and position. This particular optics requires active optical components such as phase modulators, frequency shifters, wavelength plates, and so on. Such active components can be replaced by LiNbO₃ waveguide devices, which have essentially much higher-speed capability with extremely lower drive voltage compared to the bulk-optic counterparts. LiNbO₃ is thus a promising waveguide material for integrated-optic sensors. This paper presents our recent research activities on optical integration of the heterodyne optics, especially for a fiber laser Doppler velocimeter (fiber LDV).

© 1988 Optical Society of America