高功率激光元件

Abstract

Before going into the background of challenges imposed by modern laser technology on coated optical components, this letter reviews the major aspects of coating production and control. Current deposition techniques and characterisation methods for high power optical components applied in modern laser systems are summarised and discussed. In this context, methods are considered especially for the precise control of the spectral transfer properties of optical coatings during production. Also, a short review is presented regarding laser damage in optical coatings and the corresponding measurement techniques. In addition, the outlook includes recent developments in laser technology and corresponding trends in thin film production. OCIS codes: 140.0140, 310.1860, 310.6860, 310.3840, 140.3330. doi: 10.3788/COL201008S1.0140. Since the first demonstration of the laser principle at optical wavelengths in 1960, laser development has been one of the major pacemakers for the progress in production of optical laser components. Important steps in the fabrication of optical components involve the preparation of the bulk substrate material, the polishing of the optical surface, and finally, the deposition of a coating system governing the optical functioning of the component. In most applications, the optical coating system can be identified as the weakest link in the quality chain, which has to be optimized for the reliable performance of the component. As a consequence, the study of high power laser components is mainly concentrated on optical coatings and their precise characterisation. In the course of enormous improvements of laser output power and beam parameters, ever-increasing demands are imposed on optical coatings with respect to quality, stability, and precision. The present article is dedicated to these three major challenges and to recent progresses in the fields of optical coating, production, and quality control, as well as the optimization of the power handling capability of laser components. A brief review on modern trends in laser technology and on approaches in thin film technology to accomplish the corresponding prospective tasks is also presented.