Narrow-linewidth frequency stabilized AlxGa1−xAs/GaAs laser

Abstract
Velocity‐selective magnetic optical activity in Rb vapor was used to simultaneously narrow the linewidth (500 kHz) and stabilize the frequency of an AlxGa1−xAs/GaAs laser. The frequency stability was determined by heterodyning two similar lasers and measuring their relative stability. The square root of the Allan variance, a standard figure of merit, was σy(τ)=4.9×10−12 for an averaging time of 200 s. This corresponds to a standard deviation of the beat frequency fluctuations of 1.9 kHz.