Experimental study of wavelength switchable Yb:YAG large size rectangular core crystalline waveguide mode-locking laser

We demonstrate a wavelength switchable high-power passively mode-locked laser based on a large size rectangular core crystalline waveguide and a semiconductor saturable absorption mirror. The wavelength switching is realized by controlling the polarization direction, the 1030 nm or 1050 nm mode-locked pulses are obtained. For 1030 nm single-wavelength configuration, an average power of 16.8-W with 2-ps pulse duration is achieved. For 1050 nm single-wavelength configuration, we obtained 15-W of average output power in pulses with 2.7-ps duration. This work proves that, in the large size rectangular core crystalline waveguide, the gain of 1030 nm laser is different for different polarization states, and the wavelength switching is realized.