摘要
The third-order optical nonlinearities and responses of poly（methyl methacrylate） （PMMA） coating films containing J-like aggregates of a thiadicarbocyanine dye, 3,3＇-diethyl-2,2＇-thiadicarbocyanine iodide （DTDC1）, are measured by degenerate four-wave mixing （DFWM） technique under resonant conditions. The temporal profiles of the DFWM signal of PMMA coating films containing J-like aggregates of DTDC1 are found to consist of three components： i.e., the coherent instantaneous nonlinear response （electronic response） and the two slow responses uqth decay time constants of about 0.8ps and about 7.0ps. The electronic component of the effective third-order nonlinear susceptibility, χc^（3）, of one of the present films is as high as about 2.1×10^-8 esu, and the figure of merit of third-order nonlinearity F （F=χ^（3）/α） is evaluated to be about 1.9 ×10^-13 esu cm at 850nm.
The third-order optical nonlinearities and responses of poly（methyl methacrylate） （PMMA） coating films containing J-like aggregates of a thiadicarbocyanine dye, 3,3＇-diethyl-2,2＇-thiadicarbocyanine iodide （DTDC1）, are measured by degenerate four-wave mixing （DFWM） technique under resonant conditions. The temporal profiles of the DFWM signal of PMMA coating films containing J-like aggregates of DTDC1 are found to consist of three components： i.e., the coherent instantaneous nonlinear response （electronic response） and the two slow responses uqth decay time constants of about 0.8ps and about 7.0ps. The electronic component of the effective third-order nonlinear susceptibility, χc^（3）, of one of the present films is as high as about 2.1×10^-8 esu, and the figure of merit of third-order nonlinearity F （F=χ^（3）/α） is evaluated to be about 1.9 ×10^-13 esu cm at 850nm.
