M 2 factor and kurtosis parameter of super-Gaussian beams passing through an axicon
Abstract:The effects of axicons on the M 2 factor and kurtosis parameter of super Gaussian beams(SGBs) are studied in detail. The closed-form expression for the M 2 factor of SGBs after passing through an axicon is derived, and the reason why the convergent and divergent axicons give rise to the same increase of the M 2 factor is explained physically from the similarity of the resulting irradiance distributions. The analytical propagation equation of the K parameter of SGBs passing through an axicon followed by a paraxial optical ABCD system is given, some interesting special cases are discussed. In particular, it is found that even for the Gaussian special case the K parameter is no longer a constant due to the effect of the axicon. Numerical examples are also given to illustrate our analytical results.
Document Type: Research Article
Affiliations: Institute of Laser Physics & Chemistry, Sichuan University, Chengdu, 610064 P.R. China
Publication date: September 1, 2003