Thermally controlled lenses for lasers

摘要

An apparatus and method for controlling the propagation path of a light beam are disclosed. A lens material having a temperature-dependent index of refraction is positioned in the path of the light beam. A heat source is disposed on one face of the lens material and a heat sink is disposed on the opposite face. A controller regulates the distribution of heat to the heat source and the extraction of heat from the heat sink so that a temperature gradient is formed within the lens material. The temperature gradient creates a refractive-index gradient in the lens material, causing a thermal lensing effect. The device may be used in a laser cavity for controlling laser-beam divergence caused by pump-induced thermal lensing in the gain medium.