| Abstract | The relative merits of four methods - energy balance, summation of reflections, inversion of the irradiance-transfer matrix, and solution of the integral equation - are compared by using each to determine irradiance in a multizone true sphere and in a sphere with a flat port; in the process several new solutions are presented. Although limited in applicability, the energy-balance method is by far the most direct. For the flat-port configuration the relationships among various published expressions are established; furthermore, the curved-surface interreflection irradiance is shown to be nonuniform when the initial irradiance is restricted to a part of the curved surface. © 1998 Optical Society of America. |
