Research of 3463nm KTiOAsO4 optical parametric oscillator at low repetition frequency

In order to study the optical parametric characteristics of KTiOAsO4,according to momentum and energy conservation rule and dispersion equation of the crystal,the phase-matching,gain,effective nonlinear coefficient deft,walkoff and accept angle curves were analyzed in theory through numerical simulation.Type-Ⅱ phase-matching of KTiOAsO4 crystal was adopted and the cutting angle θ=90°,the angle φ=0°.In room temperature,the idle wavelength was 3463nm by experiment.The maximum of single pulse energy was more than 22mJ,the pulse width was no more than 35.3ns,the beam divergence was no more than 8.9mrad and the repeating frequency was from 1Hz to 40Hz.The experimental results show that KTiOAsO4 crystal adapts to generate mid-infrared laser,especially to generate high energy and high peak power mid-infrared laser in future.