Comment on "Partially coherent flat-topped beam and its propagation"

We point out that the expression of the cross-spectral density (CSD) of a partially coherent flat-topped beam (PCFB) given by Ge et al. [Appl. Opt. 43, 4732 (2004)] is incorrect. The results show that the M-2 factor derived based on Ge's expression leads to M-2 < 1 in some cases, which is physically unacceptable. A new expression of the CSD for a PCFB is given. (c) 2006 Optical Society of America.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000234586900014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701OpticsSCI(E)EI6ARTICLE2366-3684