Abstract

Frequency stabilization and phase locking of lasers are required in many applications including coherent communications, interferometric sensing, and radar control. In coherent communications a frequency offset phase-locked laser serves as the local oscillator, which demodulates the FSK and PSK signals and shifts them to a chosen IF. In addition, several lasers separated by fixed frequencies can be used as transmitters and local oscillators in wideband frequency multiplexed multichannel communication systems. We demonstrate the phase locking of two 1319-nm Nd:YAG nonplanar ring lasers at microwave offset frequencies. These lasers are well suited for optical communication systems¹ because of their compactness, frequency stability, and narrow linewidth.

© 1990 Optical Society of America