The propagation characteristics of the fundamental Gaussian laser beam in absorptive and active media are investigated. There is a general reduction in the spreading of the beam on propagation in both absorptive and active media. In addition, in an active medium there is a shift of the focal plane and a reduction in the waist size of the beam.
© 2004 Optical Society of America
(260.1960) Physical optics : Diffraction theory
(260.2110) Physical optics : Electromagnetic optics
(260.2160) Physical optics : Energy transfer
(350.5500) Other areas of optics : Propagation
S. R. Seshadri, "Effect of absorption on the spreading of a laser beam," Opt. Lett. 29, 1179-1181 (2004)