Concentration of diffuse linear light sources with continuous optical elements

A new technique for geometric transformation of a diffuse linear Light sour ce into a two-dimensional symmetric virtual source is proposed and demonstr ated. It involves two cylindrical lenses and a single holographic element t hat is optically recorded with a simple and single step. The results for a specific arrangement that transforms a 40 mm x 0.4 mm source, with diffusiv e angle of 0.1 rad, into a 1 mm x 1.2 mm nearly symmetric spot are presente d. The lack of sharp boundaries in either the beam or the optical elements suppresses any diffraction losses, relaxes alignment tolerances, and improv es stability. (C) 1999 Optical Society of America.