Measurement of two-photon absorption cross-section in organic molecular salt with linear and circular polarized radiation

摘要

We report on the investigation of two-photon absorption (TPA) in 4′-Diethylamino-N-Methyl-4-Stilbazolium Tosylate (DEST) with 40 picosecond, 1064 nm linear and circular polarization laser radiation. The TPA cross-section σ_2 measured is larger for linear polarized radiation (948 GM) than that for the circular polarized radiation (840 GM). The large TPA cross-section of DEST facilitates highly directional and efficient TPA induced upconverted emission in the range of 590-640 nm even though the fluorescence efficiency of DEST is very low (～ 0.5%). The net single pass efficiency of upcon-version is ～ 7%.