Resonant Enhanced Large Third-Order Optical Nonlinearities and Responses of Polyvinyl Alcohol Coating Films Containing J-like Aggregates of a Cyanine Dye

Abstract

The third-order optical nonlinearities and responses of polyvinyl alcohol (PVA) coating films containing J-like aggregates of a cyanine dye called NK-3261 were measured by a femtosecond degenerate four-wave mixing (DFWM) technique under resonant conditions. The temporal profiles of the DFWM signal of the PVA coating films containing the J-like aggregates of NK-3261 consisted of three components, i.e., the coherent instantaneous nonlinear response (electronic response) and two slow responses with decay time constants of ca. 1.2 ps and ca. 5.6 ps. The electronic component of the effective third-order nonlinear optical susceptibility, χe(3), of one of the films was as high as ca. 1.1 ×10-7 esu at 850 nm.