2ND-HARMONIC FEMTOSECOND PULSE GENERATION IN NONLINEAR POLYMER THIN-FILM STRUCTURES

Ultrashort-pulse second harmonic applications of nonlinear poled polymeric films (NPPF) and their optimization in terms of nonlinear chromophore concentration and thin film structure are discussed, The objective of such optimization is to maximize the conversion efficiency and, more importantly, minimize the pulse distortions in ultrashort-pulse second harmonic generation. It is shown that each NPPF has a specific optimum chromophore concentration density. It is also shown that the quasi-phase-matched structures of NPPFs not only enhance the efficiency of ultrashort-pulse second harmonic generation but also minimize pulse distortions.