Time dependence of the depolarization ratio in picosecond time-resolved Raman spectroscopy. Effect of reorientation

✍ Scribed by Koichi Iwata; William L. Weaver; Terry L. Gustafson

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 474 KB
• Volume: 210
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)89098-3

✦ Synopsis

In picosecond time-resolved Raman spectroscopy, the depolarization ratio is expected to change as the time delay is varied if an anisotropy distribution of the excited state is introduced by using linearly polarized pumping light and the time resolution of the measuring system is shorter than the reorientation lifetime. The time dependence of the depolarization ratios for two intense Raman bands of tram-stilbene in the first singlet excited (S,) state was measured to demonstrate this effect. The results are explained well by a simple model that assumes the alignment of the S, distribution and its subsequent randomization.