Oven segmentation scheme for pulse shape and efficiency improvement in a picosecond second harmonic generation

Abstract

A multi-segment oven scheme is proposed to control the temperature distribution inside a MgO:PPLN crystal to generate a second-harmonic generation (SHG) pulse possessing optimum characteristics. It is found by numerical solving of SHG coupled equations and steady-state heat equation that when the oven is divided into four segments, the most optimal pulse features can be reached. While the temperature of each segment is independently set at a certain value, and the input pump is raised to 103 GW/m2, the lowest distance parameter of about 10 and the highest efficiency of around 85% is entirely expectable, indicating a desirable case whereby keeping the crystal at the phase-matching condition could not be reached.