Abstract

We have stabilized the frequency of a commercial GaAlAs laser diode by locking it to an absorption line of the oxygen A band in the spectral region of 780-769 nm (Fig, 1). This oxygen band, which consists of more than thirty lines with separations ranging from 30 to 200 GHz, can provide a reference bank for implementation of high-capacity frequency-division-multiplexed (FDM) coherent communication channels. The error signal used in the feedback control circuit of our locking scheme was generated by a frequency-modulation (FM) spectroscopic technique.¹

© 1988 Optical Society of America