Nanosecond and Picosecond Photochemistry with Lasers.
Final research rept. 1 Oct 68-30 Dec 71,
TRW SYSTEMS GROUP REDONDO BEACH CALIF
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Pulsed lasers are excellent light sources for studying primary events in photochemistry. Previously a Q-switched ruby laser and a laser-induced spark was used to observe excited singlet states of aromatic compounds on a nanosecond time scale. In the reported research the authors have extended the time resolution of laser photolysis onto the picosecond time range. They used the second harmonic 530 nm of a mode-locked neodymiumglass laser as an excitation source. The self-phase modulation continuum produced when 530nm picosecond laser pulses are focussed into glass, water and other optical media was employed. Using the continuum as a monitoring source they observed inverse Raman spectra in several molecules and a short lived transient absorption in Rhodamine 6G. Observation of short lived absorption by excited molecular states is of importance in understanding the dynamics of laser control materials such as those used for Q-switching and mode-locking. Author
- Radiation and Nuclear Chemistry