All-polarization-maintaining dual-comb fiber laser with mechanically shared cavity configuration and micro-optic component

An all-polarization-maintaining dual-comb fiber laser with a mechanical shared-cavity configuration was demonstrated. The laser cavity configuration was simplified and downsized using the micro-optic component of a saturable absorber mirror and a wavelength-division multiplexer. A high relative frequency stability was achieved with an Allan deviation of 0.02 Hz. Further, the all-polarization-maintained fiber-based configuration facilitated an integrated phase noise of the relative beat note between dual-frequency combs of 378 rad (10 Hz−1 kHz) and 9.0 rad (100 Hz−1 MHz). The simple, compact, and robust dual-comb fiber laser yielded highly mutually coherent dual-optical frequency combs without active servo control, and significantly simplified dual-comb spectroscopy.