Thermally deformable mirror to compensate for phase aberrations in high-power laser systems

摘要

We report on a thermally deformable mirror to compensate for aberrations in high-power laser systems, suitable for intracavity and extracavity implementation in laser oscillators and laser amplifiers. The adaptive mirror consists of a thin polished edge filter which is mounted on a heat sink. Local deformations of the adaptive mirror are yielded by absorbing the emission of a so-called " heating laser" in the rear-side cooled mirror substrate. Thus, imaging suitable intensity profiles on the mirror enable us to perform laterally highly resolved profiles of optical path differences (OPD) to compensate systematically for phase aberrations. For this, a digital light processing (DLP) micromirror array of a commercial projector, irradiated by a top-hat shaped " heating beam," is mapped on the adaptive mirror. Achievable deformations of the adaptive mirror have been measured using a Shack Hartmann wavefront sensor. A high lateral resolution of 0.1 mu m/mm radius and a maximal OPD of 0.569 mu m could be demonstrated successfully. (c) 2018 Optical Society of America.