Abstract

Thermal focusing and defocusing of a laser beam in an absorbing dielectric is studied when the laser operates in the TEM₀₁ mode. The paraxial-ray approximation is employed to obtain an analytical solution of the wave equation. When the refractive index decreases with increasing temperature, the electromagnetic energy converges in the x direction and diverges in the y direction; the reverse is the case when the refractive index increases with increasing temperature. The authors have also studied the geometric-optics self-focusing of laser beams operating in the (i) doughnut mode and (ii) mixed TEM₀₀ and TEM₁₀ cylindrical modes oscillating in phase opposition. In both cases, the energy of the beam concentrates around a circular ring of maximum irradiance.

© 1975 Optical Society of America

Asymmetric focusing of a laser beam in TEM₀₁ doughnut mode in a nonlinear dielectric*

M. S. Sodha, V. P. Nayyar, and V. K. Tripathi
J. Opt. Soc. Am. 64(7) 941-943 (1974)

Theory of relativistic self-focusing of laser radiation in plasmas

Heinrich Hora
J. Opt. Soc. Am. 65(8) 882-886 (1975)

Beam wander in a turbulent medium: An application of Ehrenfest’s theorem

Richard J. Cook
J. Opt. Soc. Am. 65(8) 942-948 (1975)

Transmission and reflection of a gaussian beam at normal incidence on a dielectric slab

T. Ooya, M. Tateiba, and O. Fukumitsu
J. Opt. Soc. Am. 65(5) 537-541 (1975)

Asymptotic theory of irradiance fluctuations in a beam propagating in a random medium

Alan M. Whitman and Mark J. Beran
J. Opt. Soc. Am. 65(7) 765-768 (1975)