High energy, single mode, all-solid-state and tunable UV laser transmitter

NASA is developing state-of-the-art, all-solid-state, conductively cooled, diode-pumped, single longitudinal mode, tunable, short-pulsed, and high energy UV transmitters for ozone sensing measurements based on the Differential Absorption Lidar (DIAL) technique. The goal is to demonstrate output pulse energies greater than 200 mJ at pulse repetition frequencies of 10 Hz to 50 Hz, and pulsewidths in the range of 10 ns to 25 ns at UV wavelengths of 308 nm to 320 nm. The proposed scheme is to utilize the robust Nd:YAG pump laser technology in combination with nonlinear optics arrangement comprising of a novel optical parametric oscillator (OPO) and a sum frequency generator (SFG) to generate required UV wavelengths. In this paper, recent results of the development of Nd:YAG pump laser and UV converter module are presented. At 1064 nm, an output pulse energy of 1020 mJ at 16 ns pulsewidth and 50 Hz PRF yielding greater than 7% wall plug efficiency has been demonstrated. With improved drive electronics, this pump laser has the potential to generate greater than 1.2 J/pulse. The refined OPO module to aid in the generation of >200 mJ/pulse of UV radiation is also presented. The UV transmitters are being designed for DIAL operation under strong daylight conditions from space based platforms.