Frequency-controlled cw tunable GaAs laser

Abstract

A cw single-mode tunable GaAs diode laser has been locked to an external passive cavity by making use of the dependence of the output frequency on the injection current. The resulting long-term stability of the laser optical frequency was checked by reference to a microwave frequency standard, through the light-shift effect in a cesium vapor. The laser frequency was found to track the drift of the cavity bandpass with residual variations less than 300 kHz rms. Servo-controlled frequency scanning was achieved over 5 GHz.