Efficient Second Harmonic Generation of Picosecond Laser Pulses*

For a number of applications it is desirable to frequency double the output from high-power mode-locked ruby and neodymium lasers. Second harmonic generation (SHG) in LiNb03 and KHaPO. (KDP) crystals from picosecond light pulses emitted by a Nd3+:glass laser has previously been studied theoretically and experimentally. 1-3 This letter deSCribes details of an efficient intracavity second harmonic (SH) generator that is capable of producing intense visible coherent radiation in the form of picosecond light pulses. The pump source is a 1. 062-J.I. Nd+:glass laser which is mode locked and Q switched by means of Eastman Kodak dye 9740 or 9860. The most effective nonlinear optical crystal presently commercially available for generating high-peak-power SHG light pulses was found to be a 90° phase-matchable tetragonal arsenate crystal which belongs to the familiar KDP group. • Details of the performance characteristics of CsHaAs04 (CDA) are discussed since they are significantly better than those reported for such other potential SHG materials as KHaP04> KDzP04 (KD* P), LiNb03, B3,zNaNbs0 1s, or LiI03•