Research On High Repetition Rate High Efficiency 2.1?m KTP Optical Parametric Oscillator

The wavelength of 2?m have a wide range of applications in many areas,such as laser medical treatment, laser radar, optoelectronics confrontation. Therefore, in this paper focuses on 2.1?m OPO research.This paper designed a KTP-OPO which use a a 1.06?m master oscillator power amplifier pumped bonded KTP crystal to get high repetition rate of 2.1?m high-efficiency optical parametric oscillator. First, the theory conducted with three waves coupled equations analysis, analysised of single and double resonance resonant optical parametric oscillator gain, the threshold level conversion efficiency, the design of optical parametric oscillator provides the necessary theoretical basis.In experimental, We designed the end-pumped master oscillator power amplifier structure and designed the size of the nonlinear KTP crystal, designed cutting angle, selected II phase matching, cutting the x-z plane, cutting angle of 52.3°, two bonded together bonded KTP crystal, and designed KTP-OPO operating mode, designed the cavity structure. Finally,at the repetition frequency of 50 kHz, the optical parametric oscillator output mirror selected transmittance of 20%, to achieve a high repetition rate, high efficiency 2.1?m laser output.At the repetition frequency of 50 kHz, this paper use two larger end-pumped master oscillator power amplifier structure to get 38.6W 1064 nm laser, pulse width 8.74 ns, beam quality, using 30 W of 1064 nm laser pump bonded KTP crystal realized 3.99 W 2.1?m laser output, laser wavelength of 2128 nm, a pulse width of 10.79 ns, 1064nm-2.1?m photoelectron conversion efficiency of 13.4%, beam quality.The repetition frequency of 50 kHz, MOPA structure through the front-end and back-end bond research and KTP crystal structure and OPO theoretical simulation and experimental characteristics, repetition frequency of 50 kHz, to achieve a 38.6W 1064 nm laser, pulse width of 8.74 ns, beam quality M_X~2=1.236,M_Y~21.208.Used 30 W of 1064 nm laser pump bonded KTP crystal to achieve 3.99 W 2.1?m laser output, laser wavelength of 2128 nm, pulse width of 10.79 ns, 1064nm-2.1?m conversion efficiency of 13.4%, beam qualityM_X~23.99,M_Y~=24.17.