Nonlinear absorption and photoluminescence emission in nanocomposite films of Fuchsine Basic dye-polymer system

Fuchsine Basic dye-polyvinyl alcohol composite films were fabricated and their structure, nonlinear absorption as well as linear absorption and photoluminescence properties were investigated. Switchover from saturable absorption to two-photon assisted excited state absorption with increase in intensity was observed in the open aperture Z-scan study (Nd:YAG, 532 nm, 7 ns). The effective two-photon absorption coefficient β was found to be several orders higher than that reported for rhodamine B. The dye-polymer films were characterized as nanocomposites with dye microdomains encapsulated between molecules of the amorphous polymer and having average surface roughness as low as ≈0.46 nm. The samples also exhibited intense photoluminescence emission when excited with 534 nm radiation.

62Highlights►Organic-polymer nanocomposite films of excellent surface smoothness were fabricated. ► In the Z-scan experiment, a switchover from SA to TPA occurred near the focus. ► The organic-polymer nanocomposite films displayed intense PL emission at room temperature.