Fig. 1. Schematic diagram of the experimental setup.

Fig. 2. Output power of the original fundamental laser before M3 and the signal laser with different output couplers versus the incident diode pump power.

Fig. 3. Pulse waveforms of the original fundamental laser, depleted fundamental laser, and signal laser.

Fig. 4. Spectrogram of the original fundamental laser and signal laser.

Fig. 5. Beam profile and beam quality of 1.73 μm laser. Scale bar: 1 mm.