Concentration of diffuse linear light sources with continuous optical elements

A new technique for geometric transformation of a diffuse linear light source into a two-dimensional symmetric virtual source is proposed and demonstrated. It involves two cylindrical lenses and a single holographic element that is optically recorded with a simple and single step. The results for a specific arrangement that transforms a 40 mm × 0.4 mm source, with diffusive angle of 0.1 rad, into a 1 mm × 1.2 mm nearly symmetric spot are presented. The lack of sharp boundaries in either the beam or the optical elements suppresses any diffraction losses, relaxes alignment tolerances, and improves stability.