Abstract

Optical sensors based on heterodyne interference require two interfering light beams of different frequency. In most designs both beams originate from the same source, and the difference in frequency is produced by a frequency shifter such as an acoustooptic modulator. These devices are large, expensive, and not compatible with all-fiber Interferometers. One solution, proposed by Wong and Wright,¹ is to use an integrated optic serrodyne frequency translator, consisting of a phase shifter driven with a sawtooth waveform. However, there is still the difficulty of coupling the device to fibers. We describe here an alternative approach using a fiber-optic phase shifter driven with a sawtooth waveform.

© 1985 Optical Society of America