有机染料HEASPS在不同波长时的激发态吸收和双光子吸收性质研究

Study on the properties of two-photon absorption and excited state absorption of an organic dye HEASPS at different wavelengths

提出了有机染料反式 4 [4′ (N 羟乙基 N 乙基胺基 )苯乙烯基 ] N 甲基吡啶对甲苯磺酸盐 (简称HEASPS)非线性吸收的三态模型。认为在较短波长 (<1 0 0 0nm)时 ,双光子吸收和激发态吸收同时存在。成功地解释了该染料双光子吸收峰相对线性吸收峰的两倍的明显蓝移 ,以及最高上转换效率波长相对最强吸收波长的明显红移。提出了一种新的计算方法 ,利用不同波长的非线性透过率和不同波长的上转换效率 ,求出了该染料的双光子吸收截面和激发态吸收系数。

A three-level energy model is forwarded on the nonlinear absorption properties o f a two-photon absorption (TPA) dye trans-4-[4′-(N- hydroxyethyl- N-eth ylamino)styryl]-N-methylpyridinium p-toluene sulfonate. There are TPA and excited stated absorption (ESA) at wavelengths shorter than 1000nm. The blue sh ift for the central wavelength of TPA spectrum compared with two times of the li near absorption peak and the red shift for the highest upconversion wavelength c ompared with the strongest nonlinear absorption wavelength are explained by usin g the model. Based on this model, a new method is forwarded to calculate the TPA cross section and ESA coefficient with the nonlinear transmittance and upcon version efficient at different wavelengths.