Simultaneous stabilization of spectral linewidth and oscillation frequency of an external‐cavity laser diode by fiber‐optic ring‐resonators

The oscillation spectral linewidth and the oscillation frequency of a laser diode with an external cavity have been stabilized simultaneously with an optical fiber ring resonator used as a spectrum discriminator. Stabilization of the oscillation spectrum linewidth has been carried out with control of the phase of the fed‐back light and the oscillation frequency by control of the injected current. The oscillation spectral linewidth is 2 MHz and its fluctuation is less than 10 kHz p‐p and the equivalent oscillation frequency fluctuation is 2 MHz p‐p From these results, it is confirmed that an external cavity laser diode can be used as a light source of a ring resonator‐type fiber gyroscope.