Compact diode-pumped tunable single- and dual-wavelength single-frequency semiconductor disk lasers

Optically pumped external cavity semiconductor disk laser (SDL) combines the characteristics of semiconductor laser and solid-state laser, and has important research value. In this paper, an InGaAs SDL with different emission peak from others was designed. Under free-running operation and a cooling temperature of 12 degrees C, a few longitudinal-mode continuous wave laser at 1037 nm with a maximum output power of 2.53 W and a slope efficiency of 41.3% with respect to an absorbed power of about 8.0 W was achieved. Based on this experiment, stable single-wavelength single frequency SDL with maximum output power of 1.79 W was obtained by inserting an etalon into the laser resonator. The single frequency laser was measured to have near-diffraction-limited beam quality. Flexible and continuous wavelength tuning from 1034.77 nm to 1041.10 nm of the single-wavelength single frequency SDL was also realized by introducing another etalon. Under this situation, we also obtained tunable dual-wavelength single frequency SDLs, for the first time to our knowledge. Compared to complex methods such as particular bandgap engineering design or multi-SDL resonator for generating dual-wavelength lasers, the method proposed in this work by using etalons is a simple, feasible, and low-cost solution.