Generation of 2-μ m Light Based on a Noncritical Phase Matching OPO Technique

We propose an experimental technique for efficient 2- μm light generation based on the intracavity noncritical phase matching optical parametric oscillator (OPO). Intra-cavity pumped by a diode pumped actively Q-switched Nd:YVO4laser operating at 1.3 μm, we have achieved efficient 2093-nm signal beam emission making full use of noncritical phase matching KTA-OPO. At a diode pump power of 9.8 W and a Q-switching repetition rate of 30 kHz, a signal beam with a spectral linewidth of ~ 1 nm and an average power of 1.01 W have been obtained, giving a diode pump power to signal power conversion efficiency of 10.3%. The short pulse width of ~ 3.4 ns is achieved, which is much shorter than other approaches with Q-switched operation to generate 2-μm laser beams.