Fig. 1. Experimental setup for the Tm:YLF micro laser.

Fig. 2. Energy level diagram of the Tm:YLF crystal.

Fig. 3. Output powers of the lasers with focus lengths of 40 and 37.5 mm versus the pump power.

Fig. 4. Optical–optical conversion efficiency of the lasers with focus length sof 40 and 37.5 mm versus the pump power.

Fig. 5. Relaxation oscillation of the lasers with focus lengths of 40 and 37.5 mm at the pump power of 43.6 W.

Fig. 6. Wavelengths of the lasers with focus lengths of 40 and 37.5 mm as a function of the incident pump power.

Fig. 7. Beam radius of the lasers with the focus length of 37.5 mm at the incident pump powers of (a) 25 and (b) 43.6 W.