A simple beam expander for frequency narrowing of dye lasers

Design considerations and performance of a prism beam expander are presented. Using a prism beam expander and holographic grating, a dye laser pumped by a nitrogen laser has given 15 kW of diffraction limited power in 0.1-0.2 /cm linewidth. Addition of a single etalon gave a single frequency output of 10 kW in a linewidth of less than 0.01 /cm