Abstract

Fiber sensors have recently taken advantage of the 1.3µm diode-pumped laser technology, which offers high output power in a single frequency and orders of magnitude improvement in frequency stability over semiconductor devices [1]. The small frequency jitter [2] of Nd:YAG lasers enables one to attain submicron phase noise in interferometric sensors with as much as 10 meters of optical path difference. Because non-linear fiber sensors, such as magnetic fiber sensors, which make use of a carrier to upconvert low-frequency signals to be detected, are often limited by intensity noise upconverted around the carrier [3], we have measured the intensity stability of those devices . The intensity noise in fiber sensors originates from both the laser instabilities and the drifts in the fiber launch.

© 1992 Optical Society of America