We theoretically analyze a method for matching group velocities of fundamental and second harmonic femtosecond pulses during phase matched frequncy doubling by predispersing the fundamental pulse with a prism. The method permits improved conversion efficiency by allowing crystal lengths of several millimeters without sacrificing second harmonic pulse duration. Second harmonic pulse energy and duration are analyzed for β-BaB2O4, and limiting experimental factors are discussed. The results show that the method is most advantageous for incident pulses between 0.1- and 1.0-ps duration and microjoule and higher energies and that second harmonic pulse duration and conversion efficiency are not highly sensitive to optical misalignments of the order of 1°.
© 1990 Optical Society of America
T. R. Zhang, Heung Ro Choo, and Michael C. Downer, "Phase and group velocity matching for second harmonic generation of femtosecond pulses," Appl. Opt. 29, 3927-3933 (1990)