Modeling laser beam diffraction and propagation by the mode-expansion method.
In the mode-expansion method for modeling propagation of a diffracted beam, the beam at the aperture can be expanded as a weighted set of orthogonal modes. The parameters of the expansion modes are chosen to maximize the weighting coefficient of the lowest-order mode. As the beam propagates, its field distribution can be reconstructed from the set of weighting coefficients and the Gouy phase of the lowest-order mode. We have developed a simple procedure to implement the mode-expansion method for propagation through an arbitrary ABCD matrix, and we have demonstrated that it is accurate in comparison with direct calculations of diffraction integrals and much faster.
Snyder
James J
JJ
University of North Carolina at Charlotte, Center for Precision Metrology, 9201 University City Boulevard, Charlotte, North Carolina 28223, USA. jjsnyder@uncc.edu