Ressonadores dinamicamente estáveis de com meio ativo birrefringente de Nd:YAG 

Abstract

In this work, which aimed to study the use of the active medium of Nd:YAG with thermally induced birefringence in dynamically stable resonators, it was proposed the development of a high power dynamically stable ring resonator using commercial side pumped laser modules by diodes and with birefringence compensation, obtaining 55.6 W of power in single frequency operation with polarized output in continuous mode. This power is the highest for single-frequency Nd:YAG lasers in a single resonator to our knowledge. A lithium triborate (LBO) crystal was inserted in the resonator to improve the spectral characteristics of the laser by means of non-linear losses mechanisms, with the suppression of longitudinal modes adjacent to the main mode being verified with a single frequency peak with 29 MHz width. This laser was built using commercial laser modules, making it possible to obtain a low-cost single-frequency high power laser system. Other linear resonators were also obtained with the modules: A continuous and linearly polarized laser with high beam quality and output power of 30 W with M 2 = 1.08 was found, with measured quality factor of 1.02 at 24, 8 W, and using two modules, a resonator with 76 W linearly polarized output was built with M 2 = 1.3 and 1.1 and 100.5 W of power with M 2 = 1.7 and 1, 9 in vertical and horizontal directions, respectively. Magni's equations for dynamically stable linear resonators [1] were applied to resonators with joint zones and equations and new expressions were presented.The equations for ring resonators by Silvestri et al.[2] were applied to symmetric ring resonators with a pair of curved mirrors and new expressions were presented. In particular, it has been shown that the width and position of its stability range can be adjusted independently and continuously by varying only the distances from the resonator.