Field-dressed curve

Each field free potential curve, V (R), generates a family of field-dressed potentials, Vj>n(iJ), with the result that many intersections between potential curves occur that are not present in the field-free case. The spectroscopic and dynamical consequences of these field-dressed curve crossings are understood using exactly the same methods presented in this book for field-free intersecting potentials. 

Fig. 1.2. Potential energy curves of H2 and Hj showing ionization and dressed states in a laser field. The dressed curves lead to bond softening and a distortion of the potential curve of the ground state of the ion, as will be discussed in Sect. 1.2.3...

Electromagnetic Field-Dressed Diabatic and Adiabatic Potential Energy Curves. 177... 

It is convenient to treat intense electromagnetic field problems in the dressed molecular states picture (see review by Giusti-Suzor, et al, (1995)). This picture allows one to think about intense field problems in a framework that closely resembles the weak field, diabatic or adiabatic states picture that is the primary focus of this book. In the dressed states picture the photon energy is added to, or subtracted from, the field-free potential energy curves. One obtains field-dressed potential curves. 

The electromagnetic radiation field is taken into account by adding the energy of the photons to the various molecular potential curves, Vi(R). If the photon number is initially N, when n photons are absorbed, the remaining number of photons is N — n. The resultant field-dressed diabatic state has potential energy... 

Figure 3.12 shows that the X2 + n = 0 curve is predissociated radiatively by the dressed 2 + n = 1 and n = 3 curves. The coupling between the crossing, field-dressed, diabatic states (solid curves in Fig. 3.12) is the radiative interaction,... 

Figure 3.12 Field-dressed potential energy curves for HJ interacting with a 532nm laser field. The field-dressed diabatic curves are shown as full lines. The field-dressed adiabatic curves, shown as dotted and dashed curves, correspond respectively to laser intensities of 1 x 1013 W/cm2 and 4 x 1013 W/cm2 (from Giusti-Suzor, et al., 1995).

Figure 2.1 Field-dressed potential energy curves of Hj (X = 532 nm), in the diabatic (solid lines) and adiabatic (broken lines for / = 10 W/cm and dotted lines for / = 5 x 10 W/cm ) frames. Curve-crossing regions are outlined by rectangular boxes XI, X2, and X3. The energies of the v = 2,4, 5 vibrational levels are indicated by thin horizontal lines.

Once the mechanisms of dynamic processes are understood, it becomes possible to think about controlling them so that we can make desirable processes to occur more efficiently. Especially when we use a laser field, nonadiabatic transitions are induced among the so-called dressed states and we can control the transitions among them by appropriately designing the laser parameters [33 1]. The dressed states mean molecular potential energy curves shifted up or down by the amount of photon energy. Even the ordinary type of photoexcitation can be... 

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