基于飞秒时间分辨瞬态吸收和多元瞬态光栅光谱技术对全反式Astaxanthin (AXT) 在DMSO溶剂中的超快激发态弛豫动力学进行了观测.结果表明, 光激发后AXT/DMSO体系直接发生S0→S2 跃迁, 基态漂白对应光谱范围为420~550 nm. 由S2→S1的内转换过程发生的时间常数为120~160 fs. S1态激发态吸收对应的光谱范围为550~740 nm,基态漂白恢复过程对应的是S1→S0的内转换过程, 其时间尺度为4.50~5.50 ps.

The ultrafast excited state relaxation dynamics of all-trans-Astaxanthin (AXT) in Dimethyl Sulfoxide (DMSO) was investigated using femtosecond time-resolved transient absorption and multiplex transient grating spectroscopies. The results reveal that the S0→S2 absorption transition directly occurs in the AXT/DMSO system, which corresponds to the ground state bleach in the 420~550 nm spectral region. Internal conversion that is ascribed to S2→S1 transition takes place on the time constant of 120~160 fs. The excited state absorption of the S1 state corresponds to the region of the 550~740 nm. The recovery progress of the ground state bleach corresponds to the internal conversion progress, which is attributed to the S1→S0 transition and occurs on the time scale of 4.50~5.50 ps.