Generation of 2- $\mu{\rm m}$ Light Based on a Noncritical Phase Matching OPO Technique

We propose an experimental technique for efficient 2- $\mu{\rm m}$ light generation based on the intracavity noncritical phase matching optical parametric oscillator (OPO). Intra-cavity pumped by a diode pumped actively Q-switched ${\rm Nd}{:}{\rm YVO}_{4}$ laser operating at 1.3 $\mu{\rm m}$ , 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 ${\sim}{\rm 1}~{\rm nm}$ 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 ${\sim}{\rm 3.4}~{\rm ns}$ is achieved, which is much shorter than other approaches with Q-switched operation to generate 2- $\mu{\rm m}$ laser beams.