Abstract
A free-space propagation model for broadband (spectral purity λ/Δλ ~ 1) optical fields is developed based on a Karhunen-Loéve (KL) expansion of the time-varying portion of a coherence-separable broadband optical envelope. For long characterization intervals it is found that the eigenfunctions of the KL expansion are approximated by complex exponentials of a Fourier-series expansion; the corresponding eigenvalues are approximated by samples of the temporal power spectrum, sampled at the harmonic frequencies of the Fourier-series expansion. The resulting modal expansion provides an intuitively simple interpretation of the propagation of broadband fields and allows the output field statistics to be calculated easily.
© 1980 Optical Society of America
Full Article | PDF ArticleMore Like This
V. S. Rao Gudimetla and J. Fred Holmes
J. Opt. Soc. Am. 70(8) 1015-1017 (1980)
L. Ronchi, R. Pratesi, and G. Pieraccini
J. Opt. Soc. Am. 70(2) 191-197 (1980)
Allan W. Snyder
J. Opt. Soc. Am. 70(4) 405-411 (1980)