Fig. 1. Unpolarized gain cross sections of Yb:YCOB crystal. Inset, Stark splitting energy levels of Yb3+ ion in Yb:YCOB crystal.

Fig. 2. Experimental setup for Yb:YCOB laser. SA represents saturable absorber (monolayer graphene and Cr:YAG). M1 is an input mirror directly coated on the front face of the Yb:YCOB crystal.

Fig. 3. Graphene Q-switch pulse laser generation of Yb:YCOB crystal at 1130 nm. (a) Output powers of the Yb:YCOB crystal under CW and Q-switched regimes. The dashed lines represent the fitting curves. η is the slope efficiency. (b) Lasing wavelength under CW and Q-switched regimes.

Fig. 4. Graphene Q-switched pulse laser properties. (a) Pulse width and repetition under different pump powers. (b) Corresponding individual pulse profiles. (c) Laser pulse trains with reception of 36.1 kHz.

Fig. 5. Change of pulse energy and peak power with absorbed pump power.

Fig. 6. Cr:YAG Q-switch pulse laser generation of Yb:YCOB crystal at 1130 nm. (a) Output powers of the Yb:YCOB crystal under CW and Q-switched regime. The solid lines represent the fitting curves. η is the slope efficiency. (b) Lasing wavelengths under CW and Q-switched regime.

Fig. 7. (a) Pulse width and repetition under different pump powers. (b) Corresponding individual pulse profiles. (c) Laser pulse trains with reception of 2.3 kHz.

Fig. 8. Change of pulse energy and peak power with absorbed pump power.