A high power quasi-continuous-wave yellow laser based on intracavity sum-frequency generation

Abstract

This paper reports a high-power all-solid-state yellow laser based on intracavity KTP crystal sum-frequency generation. In order to achieve high output power，three key techniques are used：Firstly，the system is designed to operate in a pulsed mode to increase the beam quality and optical-to-optical conversion efficiency under the same pump level. Secondly，thermal near-unstable resonator design and two-rod birefringence compensation is used to acquire large fundamental mode size in Nd：YAG rod. Thirdly，by optimizing an L-shaped co-folding-arm plane-concave symmetrical cavity，the two fundamentals have a high spatial overlap in the sum-frequency crystal and satisfy the power ratio requirement. As a result of the applications of these techniques，a quasi-continuous-wave yellow laser with output power of 7.6W and repitition frequency of 1.1kHz is obtained. To the best of our knowledge，this is the highest yellow laser output power produced by an intracavity sum-frequency Nd：YAG laser.