On the basis of generalized truncated second-order moments, a closed-form expression for the generalized M2 factor of hard-edge diffracted flattened Gaussian beams is derived that is determined by the beam order and the truncation parameter. Special cases are discussed. Moreover, it is shown that the M2 factor of truncated plane waves is equal to 4√3/3, independent of the aperture width.
© 2001 Optical Society of America
Baida Lü and Shirong Luo, "Generalized M2 factor of hard-edged diffracted flattened Gaussian beams," J. Opt. Soc. Am. A 18, 2098-2101 (2001)