EFFICIENT BROAD-BAND 2ND-HARMONIC GENERATION BY DISPERSIVE ACHROMATICNONLINEAR CONVERSION USING ONLY PRISMS

Using a lossless dispersive apparatus consisting of six prisms, optimi zed to match a second-harmonic crystal phase-matching angle versus wav elength to second order, we efficiently doubled tunable fundamental li ght near 660 nm over a range of 80 nm, using a 4-mm-long type I beta-b arium berate crystal without tuning the crystal angle. Another set of six prisms after the crystal realigned the propagation directions of t he various second-harmonic frequencies to be collinear to within 1/4 s pot diameter in position and 200 mu rad in angle. The measured convers ion efficiency of a 40-mJ, 5-ns fundamental pulse was 10%. (C) 1998 Op tical Society of America.