Abstract

A new method for understanding and calculating unstable resonator modes has been developed. It consists of propagating an initial uniform plane wave N round trips through the resonator, as in the Fox and Li [Bell Syst. Tech. J. 40, 453 (1961)] approach. The propagation, however, is performed entirely in collimated space that results from unfolding the resonator into its virtual images of the feedback mirror. In this unfolded space, the field after N round trips consists of a single plane-wave propagation plus the sum of diffracted waves from N pairs of virtual sources (for the strip-resonator case). The edge-diffraction function is determined from an asymptotic solution to the Huygens–Fresnel integral for an incident plane wave. The advantages of the method are that it is conceptually simple and numerically accurate and requires only minimal computer time.

© 1981 Optical Society of America

Unstable-resonator-mode derivation using virtual-source theory

W. H. Southwell
J. Opt. Soc. Am. A 3(11) 1885-1891 (1986)

Mode properties of a strip confocal unstable resonator with saturable gain

M. J. Smith
Appl. Opt. 20(9) 1611-1620 (1981)

Theory of modes in a loaded strip confocal unstable resonator

Gerald T. Moore and Robert J. McCarthy
J. Opt. Soc. Am. 67(2) 228-241 (1977)

Asymptotic theory of unstable resonator modes*

Paul Horwitz
J. Opt. Soc. Am. 63(12) 1528-1543 (1973)

Extended asymptotic theory of unstable resonator modes

Y. Q. Li and C. C. Sung
Appl. Opt. 29(30) 4462-4467 (1990)