Intraband scattering

The laser beam at 267 nm populates a large number of excited states, each one connected with a particular conformation of the helix and vibrations of the involved chromophores (simulated by the spectral width). Most of these states are delocalized over a few bases. Then, intraband scattering takes place and emission arises from excited states located at the bottom of the exciton band these low-lying states have, in general, different polarization from the initially populated states and lead to a loss of anisotropy. Intraband scattering is obviously faster than 100 fs because, at that time, the anisotropy of the... 

Additionally, in the case of triplet excitons, there is not only a spatial coherence, but also a spin coherence, which can be investigated using ESR (see also Chap. 7). It is limited by intraband scattering of excitons with fe-dependent resonance frequencies due to selective spin-orbit coupling. The measured spin coherence times... 

Nonlinear gain The nonlinear part of the gain in semiconductor lasers, which manifests itself in the gain versus photon density curve. In this case, the gain decreases with an increasing photon density due to finite intraband scattering and dynamic carrier heating. 

Time dependence, during the intraband scattering process, of the simulated fluorescence spectra. Dotted lines indicate intermediate spectra between t=0 and... 

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