Time-resolved Stark effect in rapidly varying fields

S. G. Przhebelskii

V. T. Bykovskii, Yu. S. Oseledchik, V. G. Khaladzhi

Vladimir Kuz, Г. Г. Федорук

effects, due to the propagation of laser light in optically dense media, have been observed and studied. The use of the method of Stark switching [6] has been of much assistance in overcoming experimental difficulties. In that method, time-varying coherent effects are observed through the use of cw lasers, and the interaction between molecules and laser light can be switched on and off rapidly by changing the energy interval between levels through the use of the Stark effect. The idea of changing the energy separation was subsequently implemented in ESR [7], where the use of cw microwave radiation and pulsed changes in a polarizing magnetic field (Zeeman switching) have also made it possible to detect the basic time-varying effects. Many of the new properties of time-varying phenomena which have been studied in the field of optical resonances stem from the partial excitation of a spectral line (~o 1 a, this signal is reflected by a sinusoidal signal with a frequency specified by the generalized Rabi frequency (Wl 2 + b2)1/2.

V. M. Vaǐnberg, V. D. Mur, В. С. Попов +1 more

Timothy W. Schmidt, Rodrigo López-Martens, Gareth O. Roberts

This study reports on the ac Stark effect of nitric oxide electron-vibration (vibronic) levels dressed by an intense, bichromatic laser field. The aims of the work are to make quantitative measurements of the magnitude of the ac Stark shift of vibrational levels connected by the A 2 Σ + ← X 2 Π 1/2 transition and to map out the cycle-averaged level separation during the Stark field. In pump–probe experiments at intensities up to 30 TW cm −2 , the ac Stark shift of the A 2 Σ + v A = 2 ← X 2 Π 1/2 v X = 0 transition is found to be Δ ( S ) 2←0 (800 nm) = 0.34 ± 0.05 U p , where U p is the ponderomotive energy. By varying the time delay between component fields, the time dependence of the population in the A 2 Σ + v A = 2 state is mapped out under different intensity conditions. Fluorescence monitoring of the upper level serves to identify the Stark-shifted transition and reveals that real population remains in the upper level after interacting with the short-pulse laser fields. Semiclassical calculations of NO irradiated by a bichromatic field indicate the direction of the A 2 Σ + and X 2 Π 1/2 level shifts and show that the population promoted to and retained in the A 2 Σ + state is determined predominantly by intra-Rydberg state interactions rather than by multiphoton loss processes. The calculations also indicate that the magnitude of the ac Stark effect of the A 2 Σ + ← X 2 Π 1/2 transition depends on the spatial orientation of the molecule with respect to the linear polarization sense of the applied laser field.

Patrick Hinrichs, Douglas Singleton, Nader Inan

We study the effect of a time-varying solenoidal vector potential for a quantum particle confined to a ring. The setup appears to be a time-varying version of the Aharonov-Bohm effect, but since the particle moves in the presence of fields, it is not strictly an Aharonov-Bohm effect. The results are similar to the ac Stark effect, but with a time-varying electric field coming from the vector potential, rather than the scalar potential. We compare and contrast the present effect with the standard ac Stark effect. The signature of this setup is the generation of quasi-energy sidebands which are observable via spectroscopy.