A high output power, eye-safe, LIDAR transmitter based on a KTA optical parametric oscillator (OPO) was
demonstrated. The OPO was based on a two crystal, NCPM, KTA ring cavity which was doubly resonant.
A 7ns, 30Hz, flashlamp-pumped, Q-switched Nd:YAG laser was injection seeded and used to pump the
OPO. The OPO converted the 1064 nm pump beam into a 1533 nm signal wave and 3475 nm idler wave.
In addition to demonstrating a high power OPO system, we investigated the effects of seeding the pump
laser on the OPO's conversion efficiency, oscillation threshold, maximum signal power, and beam quality.
The power conversion efficiency between the signal and the injection seeded pump was 22% with an
oscillation threshold of 104 MW/cm2 (500 mJ) and a maximum signal power of 6.44 W (215 mJ). The
power conversion efficiency between the signal and the unseeded pump was 24% with an oscillation
threshold of 77 MW/cm2 (367mJ) and a maximum signal power of 7 W (233 mJ). The beam quality of the
signal beam was produced an M2 =15. When the pump laser was seeded, the full angle divergence improved
by nearly a factor of five.