Femtosecond resonance Raman and fluorescence probing of molecules: the predissociation of IBr

✍ Scribed by Moshe Shapiro

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 112 KB
• Volume: 31
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(200001/02)31:1/2<59::aid-jrs499>3.0.co;2-j

✦ Synopsis

Computations, based on a uniform theory of resonance Raman and resonance fluorescence, of spontaneous light emission from a predissociating evolving wave packet of IBr molecules are presented. We show that the wave-packet dynamics, as monitored by the time dependence of the emission signal, is strongly dependent on the excitation pulse. In addition, it is shown that the peak in the emission during the excitation pulse (the 'pure' resonance Raman peak) is not coincidental with, but comes after, the excitation pulse peak. As the excitation pulse becomes shorter, the delay in the appearance of the pure Raman signal becomes progressively longer, relative to the pulse duration. It is also shown that large transient fluctuations in the yield to produce different ground vibrational states are exhibited at short times. These fluctuations, the magnitude of which depends critically on the duration of the excitation pulse, gradually disappear until the long-time ratio between different vibrations is established.