Frequency stabilization of a continuous-wave Ti:sapphire laser

Measurements of the spectral density of frequency fluctuations are reported for an actively stabilized cw Ti:sapphire laser. For a servo loop incorporating an intracavity translatable mirror and an external-cavity acousto-optic modulator, a linewidth of 1.0 kHz rms is obtained for the fluctuations of the laser frequency as recorded within the servo loop. The modulation index associated with the frequency deviations is considerably less than one over most of the Fourier spectrum, indicating operation in a domain of small phase noise for the fluctuations of the electric field.