How many times is a laser beam diffraction-limited?

S. Bollanti, P. Di Lazzaro, D. Murra

Research output: Contribution to journalArticle

14 Citations (Scopus)


We present an approach to the definition and estimation of the "times diffraction limit" (TDL) of highly diffracted laser beams that takes into account the near- and far-field energy distribution of the real beam instead of an ideal Gaussian beam. We have used it to find the TDL factor of two hard-edge-unstable-resonator laser beams having different quality and spatial energy distributions. The results are compared with the widely used beam quality parameter M2. The discrepancy between our TDL and the M2coefficient becomes significant when the near-field energy distribution of a spatially coherent beam deviates from the pure Gaussian shape.
Original languageEnglish
Pages (from-to)503 - 513
Number of pages11
JournalOptics Communications
Issue number1-6
Publication statusPublished - 15 Jan 1997
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

Cite this