Berlin 2001 – scientific programme
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A: Atomphysik
A 5: Posters Tuesday (Photoionisation, Multi Photon Processes)
A 5.40: Poster
Tuesday, April 3, 2001, 12:30–15:00, AT3
Tunneling Photoionization in a Strong Bichromatic Laser Field — •Vladimir Pazdzersky1 and Vladimir Usachenko2 — 1Physics Department, National University of Uzbekistan, 700174 Tashkent, Uzbekistan — 2Institute of Applied Laser Physics, Nakashlyk str.,1, 700185 Tashkent, Uzbekistan
In the presented contribution the process of electron tunneling through one-dimensional non-stationary barrier created by atomic potential and external electromagnetic (EM) bichromatic field consisting of coherent superposition of the fundamental laser field of frequency ω ( ω ≪ Ip, where Ip is the ionization potential of a field-exposed atomic system; the atomic system of units is used) and its second harmonic is considered and studied theoretically. Within frame of imaginary time method [1] the gauge-invariant analytical expression for probability of tunneling photoionization has been derived in standard exponential form. The derived analytical expression (which is an analogue of the famous Keldysh formula for photoionization probability generalized for a case of bichromatic EM field) is analysed for various limiting values of so called the adiabaticity parameter γ=(ω ·√2· Ip)/E1 and studied depending on the ratio α =E2/E1 of electric field strengths of incident bichromatic field harmonics.
The research described in this presentation was made possible in part by Award No.ZP2-2279 of the U.S. Civilian Research and Development Foundation (CRDF) for the Independent States of the Former Soviet Union.
[1] Perelomov A.M., Popov V.S. and Terent’ev M.V., 1966, Zh.Exp.Teor.Fiz., v.51, p.309.