The Exact Solution of the Gaussian Laser Beams Propagation in Free Space Under the Non-Paraxial Condition

• Main Authors: Hsiang-Hung Hsiao, 蕭翔鴻
• Other Authors: Chen-Wen Tarn
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/nr47bs

碩士 === 國立臺灣科技大學 === 電子工程系 === 107 === Gaussian light beam propagation in free space has been a popular research topic due to its wide application. The propagation of the Gaussian laser beam in free space can be properly depicted by Maxwell’s wave equation. All the existed solutions of the wave equation are mostly under the paraxial approximation, i.e. the propagation of light is limited to a small angle deviation from the optic axis. In this thesis, we propose a novel approach to solve the wave equation without the paraxial approximation and have derived an analytic representation for the Gaussian light beam. We start with the wave equation and use the angular spectrum representation and the optical transfer function to obtain the exact representation of the Gaussian beam under non-paraxial approximation. A set of simulation results provided to check the validity of our approach and compare the difference between the solution under the paraxial approximation.