High-peak-power, eye-safe, nanosecond diode-pumped Q-switched lasers

We have developed high-peak-power nanosecond laser transmitters for our long-range laser rangefinder. The 940 nm wavelength laser diodes are used to pump the Er:Yb:glass crystal. To generate nanosecond pulses with high peak power, we employ both passive and active Q-switching techniques. For active Q-switching, an 80 MHz acousto-optic modulator is utilized, while Co:Spinel crystals are used for passive Q-switching. The fabricated lasers achieved maximum pulse energies of over 1.5 mJ and 7.4 mJ for passively and actively Q-switched configurations, respectively. Based on pulse energy and pulse width, the peak power reaches up to 0.3 MW for the passively Q-switched laser and 1 MW for the actively Q-switched laser.