On the methods for estimating beam parameters of super-imposed hermite-caussian modes

摘要

In many applications, it is necessary to evaluate the beam parameters of the basis Hermite-Gaussian functions which are used to decompose a given laser beam. This paper compares two methods for estimating the beam parameters, both of which ar based on intensity meausremet. One is an exact optimization method, which can find the optimal beam parameters but has high computational demands. The other is a moment method which requires less computation but only yields approximations to the optimal beam parameters and whose application is limited to lbeams close to Gaussian or a mixture of incoherent Hermite-Gaussian modes. It is found that the moment method can provide siufficiently accurate results in certain circumstances.