Two-photon absorption spectra have been measured for bis-donor diphenylpolyene derivatives with varying conjugation lengths and end groups. Large two-photon absorptivities are observed via nanosecond nonlinear transmission measurements in comparison to picosecond nonlinear transmission and two-photon excited fluorescence methods, which suggests a large contribution of excited-state absorption to the nanosecond nonlinear transmission results. These results are reasonably well modeled as a combined two-photon and two-photon induced excited-state absorption process. Strong nonlinear absorption of nanosecond pulses is observed for bis(diarylamino)biphenyl derivatives at 525 nm. This blue shifted nonlinear absorption, relative to bis(dialkylamino)stilbene, makes possible the design of broadband optical limiting materials based on a combination of derivatives with varying conjugation lengths and end groups. We have demonstrated the feasibility of achieving broadband response using a tandem combination of cells containing three such compounds.
|Original language||English (US)|
|Number of pages||19|
|Journal||Molecular Crystals and Liquid Crystals Science and Technology Section B: Nonlinear Optics|
|State||Published - Jun 1 1999|
|Event||Proceedings of the 1998 1st International Workshop on Optical Power Limiting - Cannes, France|
Duration: Jun 28 1998 → Jul 1 1998