A geometrical optics theory is used to investigate transmission of radiation in overmoded hollow circular waveguides, with either metal or dielectric walls, in the case that the incident beam is injected into the waveguide by focusing to a waist centered on the guide axis. Expressions are derived for irradiance distributions and transmission coefficients, both for the total radiation and for a plane polarized component surviving in the guide. The effect of directing an initial Gaussian beam at an angle to the guide axis is discussed. Comparisons are made with the work of other authors, and new experimental observations are reported.
© 1985 Optical Society of America
B. S. Frost, P. M. Gourlay, N. R. Heckenberg, and S. T. Shanahan, "Geometrical optics treatment of circular lightguides," Appl. Opt. 24, 4414-4431 (1985)