M^2 factor of Bessel–Gauss beams

R. Borghi, M. Santarsiero
1997 Optics Letters  
We derive the analytical expression of the M 2 factor of a Bessel -Gauss beam of any order and discuss its behavior for high and low values of the width of the Gaussian prof ile. The case of unapertured Bessel beams can be treated as a limiting case of our analysis.
doi:10.1364/ol.22.000262 pmid:18183169 fatcat:4c5l3bukg5eatfrxoi7f7oyjua