Effective Aperture in Periodically Poled Mg-Doped Stoichiometric LiTaO3for Quasi-Phase-Matched Optical Parametric Oscillation

A two-dimensional mapping method was employed to investigate the homogeneity of optical parametric oscillator (OPO) performance, such as output power distribution, slope efficiency, and oscillation threshold, based on periodically poled 1 mol % Mg-doped stoichiometric LiTaO3 devices fabricated by single and multi-pulse methods. The output power decreased from the electrode-patterned face to the opposite face at low pump intensities and became homogenous over the aperture at high pump intensities. The devices fabricated by the two methods showed no large differences in OPO properties, except for better homogeneity in depth for multi-pulse devices. A large effective aperture (fluctuation < 10%) of 1.4×1.3 mm2 was obtained in both types of devices.