Axisymmetric Laser Sources with Planar Gain Media

本项目将研究一种从平面几何的有源介质中产生轴对称激光输出的新方法。采用一种新型的内腔光束变压器，在不降低亮度的情况下，将尺寸由平面激发体积决定的高椭圆腔模式转换为圆形模式。该方案将应用于高功率、二极管泵浦、薄板和“厚”平面波导固态激光器，与以前的设计相比，它有望改善输出光束质量，从而获得更高的亮度和扩展的功能。将对束流变压器及其在平面器件中的应用进行详细研究，以建立谐振器设计准则、热效应的影响以及该技术的主要限制。该项目还将探索几种激光配置(例如，高平均功率连续波激光器和调Q激光器)，旨在展示通过这种方法获得的主要好处。然而，这项工作的主要目的是表明，基于平面有源介质和光束转换器的组合的固态激光器，可以竞争和补充基于光纤和薄盘技术的固态光源，提供高功率和高亮度的潜力，增加操作模式的灵活性和紧凑的格式，从而满足一系列应用的需求。

This project will investigate a new approach for generating axisymmetric laser output from active media with a planar geometry. A novel intracavity beam transformer will be employed to convert the highly elliptical cavity mode, with dimensions determined by the planar excitation volume, to a circular mode without degradation in brightness. This scheme will be applied to high-power, diode-pumped, thin-slab and 'thick' planar waveguide solid-state lasers where it offers the prospect of improved output beam quality, and hence higher brightness, as well as extended functionality compared to previous designs. A detailed study of the beam transformer and its application to planar devices will be conducted to establish resonator design criteria, the impact of thermal effects and the main limitations of the technique. The project will also explore several laser configurations (e.g. high-average-power CW and Q-switched lasers) aimed at demonstrating the key benefits to be derived via this approach. However, the main ambition of this work is to show that solid-state lasers based on a combination of planar active media and the beam transformer, can both rival and complement solid-state sources based on fibre and thin-disc technology, by offering the potential for high power and high brightness with added flexibility in mode of operation and a compact format, thereby meeting the needs of a range of applications.