For a Gaussian beam, the Rayleigh length is given by
A related parameter is the confocal parameter b, which is just two times the Rayleigh length:
Femtosecond pulses help physicists go to extremes. (laser physics research)(includes related information on short-pulse laser)
Nov 26, 1993; Physicists have known for centuries that one of the surest ways to make new discoveries is to go to extremes: shorter timescales,...
Nonlinear optical studies of newly synthesized polythiophenes containing pyridine and 1, 3, 4-oxadiazole units.(Report)
May 01, 2009; INTRODUCTION Nonlinear optics has drawn increasing attention from researchers because of its potential applications in optical...