Time‐resolved degenerate four‐wave mixing studies of solid‐state poly(p‐phenylene) oligomers

摘要: We have measured χ(3) for a series of solid‐state samples polyphenylene oligomers, (Ph)n, where n=4–8 is the number phenyl ring units, using optical pulses 140 fs duration and 650 nm wavelength. A degenerate four‐wave mixing (DFWM) signal was only observable n≥6, thereafter values increased monotonically with n. Measurements linear absorption are also reported. Although DFWM measurements were performed at wavelengths far from resonance, figure merit χ(3)/α essentially flat beyond n≥6. In contrast to previous studies oligomers in solution, principal nonlinear responses instantaneous within temporal resolution.