Design an‎d simulation of 1kW compact disk laser at near fundamental mode beam quality

10/6/2026 12:00:00 AM

In this thesis, a solution is proposed for designing a stable disk laser resonator that can achieve high power an‎d beam quality close to the fundamental mode with a short effective length. This objective has been pursued through two software an‎d hardware methods. In the software aspect, designing such a resonator necessitates developing an appropriate formulation to optimize considerations of spot size, misalignment sensitivity, an‎d dynamic stability. In this context, the matrix method an‎d Gaussian beam propagation using the ABCD law for Gaussian beams have been employed to analyze the fundamental mode spot size within the resonator, misalignment sensitivity, an‎d dynamic stability in multi-folded resonators, all aimed at achieving a short effective length. The optimal geometric parameters of the resonator are calculated an‎d derived by applying length constraints, permissible misalignment sensitivity, an‎d dynamic stability ranges. The plot of the spot size on the mirrors an‎d the misalignment sensitivity as a function of the radius of curvature of the disk (due to thermal lensing) was examined for the obtained results to determine the optimal design parameters. Utilizing this design algorithm, several resonators with short effective lengths are presented as examples. In these examples, the length of the resonator arms reaches up to 50 cm, an‎d the fundamental mode spot size on the active material exceeds 2.4 mm, while also ensuring good dynamic stability an‎d low misalignment sensitivity. The approach an‎d design algorithm presented in this project can be utilized to create a stable resonator for disk lasers an‎d other types of lasers. Using the misalignment sensitivity calculation solution, a pointing sensitivity parameter has been established that offers an estimate of pointing stability, which can be beneficial in laser design. In the hardware component, the long lengths of the resonator are compressed between pair parallel flat mirrors. During repeated folding, one of the most critical factors to consider is the sensitivity to misalignment. The implementation of pair parallel flat mirror optical elements in the resonator necessitates the development of an appropriate formulation to optimize considerations regarding misalignment sensitivity. In this context, employing the matrix method an‎d Gaussian beam propagation through the ABCD law for Gaussian beams, the fundamental mode spot size within the resonator an‎d the misalignment sensitivity have been calculated an‎d analyzed using MATLAB software. Using the pair parallel flat mirror optical elements as a case study, several resonator designs with short effective lengths have been presented. In the examples provided, the effective length of the resonator reaches up to 30 cm, an‎d the fundamental mode spot size on the active material exceeds 2.8 mm, while also ensuring good dynamic stability an‎d low sensitivity to misalignment. The findings of this research indicate that the arms of each resonator can be shortened by employing pair parallel flat mirrors without significantly increasing the systemʹs sensitivity to misalignment.

ليزر پرتوان , ساختار هندسي , تشديدگر ليزر ديسك , طول موثر , كيفيت باريكه , حساسيت ناهمترازي

High-power laser , Geometric structure , Disk laser resonator , Effective length , Beam quality , Misalignment sensitivity

Hamid Sarvalishah

Mahdi Shayganmanesh