Gaussian-Hermite and Gaussian-Laguerre Laser Modes: Simulation andCharacterisation

摘要

Mathematical expressions of high-order Gaussian-Hermite and Gaussian-Laguerrelaser modes have been derived for the purpose of simulating laser beams. Using Matlab code, the transversal electric field and intensity distributions, constructed was linear combinations of the higher order modes of rectangular or cylindrical symmetry, can be presented graphically, and the associated beam quality parameters calculated for various beam configurations, It is shown how a linear combination of fundamental Gaussian-Hermite of Gaussian-Laguerre modes can be used to reconstruct an arbitrary 'experimental' intensity distribution. The expansion coefficients are obtained through a least square fitting routine (FORTRAN) where experimentally determined M2 values are used as constraints. This enables accurate tracing and modelling of various laser beams where the intensity distribution is a decisive factor, such as in non-linear optics for laser protection applications.