Two-photon pumped upconversion and nonlinear optical properties of a new lasing dye: HMASPS

摘要

Two-photon pumped frequency upconversion optical properties and two-photon absorption (TPA) induced nonlinear absorption of a new dye, trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate (abbreviated to HMASPS) have been experimentally investigated. This new dye exhibits strong superradiation properties when the pumping power is above its threshold. The superradiation upconversion efficiency from 900 to 1150nm and the nonlinear absorption from 720 to 1100 mm have been measured. The largest effective molecular TPA cross-section was measured to be 44.3 * 10~(-48) cm~4 ·s·photon~(-1) at 920 nm. At 1064 nm, it was 2.77 * 10~(-48) cm~4 ·s·photon~(-1), much smaller than that at 920nm. The highest conversion efficiency is 7% at 990 nm, whereas 4.2% at 1064nm.