Single-cavity dual-repetition-frequency self-mode-locked Tm,Ho:YLF laser based on the polarization multiplexing method

The single-cavity dual-repetition-frequency self-mode-locked Tm,Ho:YLF laser is first demonstrated. Combining the natural birefringence characteristic and the soft-hole Kerr lens effect of gain medium itself, the orthogonally polarized dual-repetition-frequency self-mode-locked Tm,Ho:YLF laser with a single cavity was successfully realized. For the π-polarized and σ-polarized pulse lasers, the balanced average output powers of 282 mW and 298 mW were attained at an absorbed pump power of 2.16 W, the pulse repetition frequencies were 1.7148 GHz and 1.7173 GHz, and the output wavelengths were 2065.3 nm and 2063.8 nm. To the best of our knowledge, this is the first single-cavity dual-repetition-frequency self-mode-locked solid-state laser in the 2 µm waveband.