A High Conversion Efficiency Q-Switched Intracavity Nd:YVO$_{4}$/KTA Optical Parametric Oscillator under Direct Diode Pumping at 880nm
Li-Jiao He1,3, Ke Liu1,2**, Nan Zong1,2, Zhao Liu1, Zhi-Min Wang1,2, Yong Bo1,2, Xiao-Jun Wang1,2,, Qin-Jun Peng1,2, Da-Fu Cui1,2, Zu-Yan Xu1,2
1Key Lab of Solid-state Lasers, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 2Key Lab of Functional Crystal and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 3University of Chinese Academy of Sciences, Beijing 100190
Abstract：We report a high conversion efficiency Q-switched Nd:YVO$_{4}$/KTiOAsO$_{4}$ (KTA) intracavity optical parametric oscillator (IOPO) operating near 3.5 μm based on direct 880 nm laser diode (LD) pumping. A maximum average idler output power of 2.6 W with a pulse width of about 7.9 ns is achieved under an absorbed LD power of 45.4 W at a pulse repetition rate (PRR) of 10 kHz. The maximum optical-optical conversion efficiency from LD power to OPO mid-infrared (MIR) output of 6.74% is achieved. To our knowledge, this is the highest conversion efficiency for a KTA-IOPO by exploiting a Q-switched laser as the parent fundamental pump source. The beam quality factors $M^{2}$ of the MIR beam at the full output power with a PRR of 10 kHz are within 2.12 in both the horizontal and vertical directions, indicating a near Gaussian mode.
2019, Vol. 36 
