CANCELLATION OF ASSOCIATED FREQUENCY DITHERING IN A SINGLE-FREQUENCY COMPOUND-RING ERBIUM-DOPED FIBER LASER

The stabilizing mechanism of a single-frequency compound-ring erbium-d oped fiber laser is greatly improved by canceling the associated frequ ency dithering. This is achieved by exploiting the filter feature of a n optical fiber compounding resonator to produce a net resultant inten sity modulation. The theory of this cancellation method, derived from the phase resonant condition of the compound-ring resonator, shows tha t a full cancellation of the frequency dithering can be attained when two antiphase dithers are applied. Experimentally, the frequency jitte r of the laser is greatly suppressed and the linewidth is less than 5 kHz.