Dynamical optical response

Dynamical optical responses of periodically modulated media... 

To smnmarize, we have briefly reviewed a few recent works on the steady and dynamical optical responses of ultracold atoms and diamond N-V color centers dressed by a SfF coupling in the Lambda configiu ation. 

Kobayashi T 1994 Measurement of femtosecond dynamics of nonlinear optical responses Modern Noniinear Optics part 3, ed M Evans and S Kielich Adv. Chem. Rhys. 85 55-104... 

In view of this apparent contradictory outcome from the transport and magnetic properties, we were motivated to investigate the dynamics of the charge excitation spectrum by optical methods. In fact, the optical measurement is a powerful contactless experimental tool which should in principle allow to unfold the disagreement between and p(7 since the optical response of a metal... 

Figure 18. Dynamical optical absorption responses for (a,c) the polyimide film implanted with 5 x 10 Au /cm and for (b,d) the virgin film obtained upon different exposures to (a,b) methanol vapors (6000 ppm) or (c,d) to ethanol vapors (6000 ppm).

In conclusion, we were able to reproduce the optical response of GFP with a novel photodynamical model which includes VER, an energy-dependent ESPT, and an additional decay pathway leading to internal conversion of the protonated chromophore. In particular, the non-exponentiality of the kinetics is traced back to VER dynamics which are slower than the primary ESPT. This might be attributed to the highly rigid tertiary structure of the protein which protects its chromophore from inelastic collisions with the aqueous surroundings. 

The previous discussion shows that the relaxation processes emerge from the quantum dynamics under appropriate circumstances leading to the formation of time-dependent quasiclassical parts in the observable quantities. Let us add that quasiclassical and semiclassical methods have been recently applied to the optical response of quantum systems in several works [65, 66] where the relation to the Liouville formulation of quantum mechanics has been discussed, without however pointing out the existence of Liouvillian resonances as we discussed here above. The connection between the property of chaos and n-time correlation functions or the nth-order response of a system in multiple-pulse experiments has also been discussed [67, 68]. 

A mixed quantum classical description of EET does not represent a unique approach. On the one hand side, as already indicated, one may solve the time-dependent Schrodinger equation responsible for the electronic states of the system and couple it to the classical nuclear dynamics. Alternatively, one may also start from the full quantum theory and derive rate equations where, in a second step, the transfer rates are transformed in a mixed description (this is the standard procedure when considering linear or nonlinear optical response functions). Such alternative ways have been already studied in discussing the linear absorbance of a CC in [9] and the computation of the Forster-rate in [10]. 

TDHF [52, 53] is one of the most widely-employed ab initio techniques to evaluate nonlinear-optical response tensors. The fDHF approach is size consistent but cannot account for the finite lifetime of the excited states. The matrices of the TDHF equation are expanded in a Taylor series of the perturbation due to the static and/or dynamic electric fields and are solved for each order [52, 53], The so-obtained successive field-derivatives of the density matrix are then inserted into the expressions for the hyperpolarizability,... 

In nanocomposite media, is worth about a few picoseconds (see 8.3.2.3 below). Eq. (30) then helps explaining the fact that, as noticed in the preceding section, xOl values measured with femtosecond pulses are smaller than those obtained with longer pulsewidths. However, dynamical thermal effects are likely to play a crucial role in the material nonlinear optical response, as will be shown in tire following. As their influence depends on the excitation temporal regime, the measurement analysis is not as simple as one could expect from the only characteristic time comparison of Eq. (30). We now go deeper into these thermal effects. 

Thermal effects in the dynamics of the optical response. As the physical... 

To fully develop the photonic and material components of quantum-optical response invites the application of quantum electrodynamics (QED). The defining characteristic of this theory is that it addresses every optical interaction in terms of a closed dynamical system where light and matter are treated on an equal footing, each component addressed with full quantum-mechanical rigor. It is a theory whose predictions have been tested to a higher degree of precision... 

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