Dark pulses for resonant two-photon transitions
نویسندگان
چکیده
We investigate the excitation of an atom or molecule via two-photon absorption induced by an ultrashort laser pulse in the perturbative intensity regime. We show that the probability for a resonant transition, i.e., with an intermediate state within the spectral width of the pulse, can be reduced to zero by pulses having a -phase step at a certain detuning from the central frequency. Our theoretical predictions are confirmed by numerical calculations for the 4s→4d transition in the potassium atom.
منابع مشابه
Transform-Limited Pulses Are Not Optimal for Resonant Multiphoton Transitions.
Maximizing nonlinear light-matter interactions is a primary motive for compressing laser pulses to achieve ultrashort transform limited pulses. Here we show how, by appropriately shaping the pulses, resonant multiphoton transitions can be enhanced significantly beyond the level achieved by maximizing the pulse's peak intensity. We demonstrate the counterintuitive nature of this effect with an e...
متن کاملTWO PHOTON TRANSITIONS IN THE OPTOGALVANIC SPECTRUM OF NEON
Seventeen two-photon transitions for neon have been observed in the 580- 635 nm spectral region for use in the spectroscopic study of its higher excited levels, which are not accessible by one-photon absorption. To compare the two and one-photon absorption signals originating from the same lower level, an effort was made to record single-photon optogalvanic spectrum in the available wavele...
متن کاملModulation of attosecond beating in resonant two-photon ionization.
We present a theoretical study of the photoelectron attosecond beating due to interference of two-photon transitions in the presence of autoionizing states. We show that, as a harmonic traverses a resonance, both the phase shift and frequency of the sideband beating significantly vary with photon energy. Furthermore, the beating between two resonant paths persists even when the pump and the pro...
متن کامل. op tic s ] 1 3 M ay 2 00 1 Dark Area Theorem
We report the discovery of a “dark area theorem,” a new quantum optical relation for propagation of unmatched pulses in thick three-level Λ-type media. We define dark area and derive the dark area theorem for a coherently prepared and inhomogeneously broadened lambda medium. We also obtain the first equation for the spatial evolution of the dark state amplitude prior to pulse-matching. Many adv...
متن کاملTime-dependent analysis of few-photon coherent control schemes
We investigate the coherent control of nonresonant two-photon excitation and (2 + 1) photon ionization processes from the time-dependent perspective. To this end, we have solved the time-dependent Schrödinger equation for a hydrogen atom interacting with an ultraviolet laser field. Results are obtained for symmetric and antisymmetric phase distributions leading to dark and bright pulses, for wh...
متن کامل