Light-dressed states

Figures 9A and 9B are photofragment images of D+ following irradiation of D2 with 532-nm light. All of the features can be assigned to dissociation of different vibrational levels of D2 by nominally either one-, two, or three-photon absorption. Because two-photon absorption to the 2p

Although we interpreted our experimental results with the motion of nuclear packets on the light-dressed ground state of the parent ions, a pump-probe scheme could also explain the pulse width dependence. When two successive pulses are interacted with molecules with a proper interval, the second pulse can be adjusted to achieve synchronicity with the motion of the nuclear wave packet of an excited state. This results in energy transitions to... 

Fig. 18.1 A dressed-state model that is used in the text to describe absorption, emission, and elastic (Rayleigh) and inelastic (Raman) light scattering. g) and. v> represent particular vibronic levels associated with the lower (1) and upper (2) electronic states, respectively. These are levels associated with the nuclear potential surfaces of electronic states 1 and 2 (schematically represented hy the parabolas). Rj are radiative continua— 1 -photon-dressed vibronic levels of the lower electronic states. The quasi-continuum L represents a nonradiative channel—the high-energy regime of the vibronic manifold of electronic state 1. Note that the molecular dipole operator /t couples ground (g) and excited (s) molecular states, but the ensuing process occurs between quasi-degenerate dressed states g,k and 5,0).

Fig. 18.7 A schematic display of light scattering/excitation-fluorescence process. Shown are the relevant molecular states and the dressed states in) and out) used in the calculation. The arrows denote thermal population transfer within the intermediate state manifold. The shading on levels p and 5 corresponds to energy level fluctuations that leads to pure dephasing.

Figure 26 can also be interpreted in a quantitative way in analogy with the dressed state description of interaction of atoms with intense light [112]. In terms of the dressed modes c and d of Eq. (126), if A / 0, in place of the Hamiltonian (125), one gets... 

The first observation of LICS in photo-absorption was made by Heller et al. [41] in Cs. They employed a circularly polarized dressing laser to embed a bound state in an ionization continuum. The probe laser field was tunable and linearly polarized. Since linearly polarized light is a sum of left-handed and right-handed circular components, and only one such component dresses up the continuum, the effect could be well detected by comparing the line shape of one component relative to the other [42]. 

Because the extent of localization of the dressed photon is equivalent to the nanometric particle size, the long-wavelength approximation, which has always been employed for conventional light-matter interaction theory, is not valid. This means that an electric dipole-forbidden state in the nanometric particle can be excited as a result of the dressed photon exchange between closely placed nanometric particles, which enables the operation of novel nanophotonic devices. Details of such devices will be reviewed in Sect. 1.4. 

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