Ultrafast nonlinear optical properties of dye-doped PMMA discs irradiated by 40 fs laser pulses

✍ Scribed by Yuanqin Xia; Yugang Jiang; Rongwei Fan; Zhiwei Dong; Weijiang Zhao; Deying Chen; G. Umesh

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 410 KB
• Volume: 41
• Category: Article
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2009.01.011

✦ Synopsis

The two-photon absorption (TPA) characteristics of PMMA discs doped with three different dyes were studied using an fs-pulsed Ti-Sapphire laser as the pump source, and employing the open-aperture Z-scan technique. TPA cross-sections obtained for PMMA doped with the dyes PM597, DCM and rhodamine 6G-rhodamine B (co-doped) were found to be equal to 24.7, 33.3 and 32.3 GM, respectively (1 GM ¼ 10 À50 cm 4 s phot À1 mol À1 ). Furthermore, two-photon fluorescence was measured for the samples containing DCM and rhodamine 6G-rhodamine B (co-doped). Compared to the one-photon fluorescence spectrum, the peaks in the two-photon fluorescence spectrum were red shifted and the extent of red shift increased with increasing doping concentration. We have also observed that the red shift in the two-photon fluorescence peak of the samples in the solid form is much larger than that in the solution state. This phenomenon could be explained by a twisted intra-molecular charge transfer model.