Fig. 1. Schematic diagram of the experimental setup for the 1.3 μm Nd:YAG Q-switched laser. M1, high reflector; M2, output coupler; P1, P2, thin-film polarizer; LM1, LM2, laser module; QR, 90° quartz rotator; AQ1, AQ2, acousto-optic Q-switch; F1–F4, lens; FP, Fabry–Perot etalon; HW1, HW2, half-wave plate; BS1, BS2, beam splitter; LBO, LiB3O5 crystal; PM1, PM2, powermeter.

Fig. 2. Temporal profile of (a) the pulse trains for LD pump and free running mode, (b) enlarged single pumping pulse and free running laser pulse, (c) the pulse trains for Q-switched laser, and (d) enlarged single Q-switched laser pulse.

Fig. 3. Transmission curves at 1319 and 1338 nm versus (a) the tilt angle and (b) temperature of etalon with 1 mm thickness.

Fig. 4. Spectra with a wavelength range from 1300 nm to 1360 nm at different angle of etalon: (a) 0.7 deg, (b) 1.08 deg, (c) 1.21 deg, (d) 1.3 deg, and (e) 1.5 deg.

Fig. 5. Wavelength tuning of (a) 1319 nm and (b) 1338 nm versus the temperature of etalon, and stability measurement of (c) 1319 nm and (d) 1338 nm within 20 min.

Fig. 6. Output power and pulse duration of 1.3 μm Q-switched laser as a function of incident pump power at 808 nm. Inset, power stability in 10 min.

Fig. 7. Measured beam quality and far-field beam profile at the maximum output power.

Fig. 8. Spectra of the red laser at (a) 659 nm for 45°C of LBO, (b) 664 nm for 42°C of LBO, and (c) 669 nm for 58°C of LBO.

Fig. 9. Output power of the red laser as a function of the input power at 1.3 μm.

Fig. 10. Power stability test of red 659 nm laser over 1 h. Inset, 2D beam spatial profile.