Back to Search
Start Over
Transient absorption and reshaping of ultrafast XUV light by laser-dressed helium
- Source :
- Phys. Rev. A 83, 013419 (2011) [12 pages]
- Publication Year :
- 2010
-
Abstract
- We present a theoretical study of transient absorption and reshaping of extreme ultraviolet (XUV) pulses by helium atoms dressed with a moderately strong infrared (IR) laser field. We formulate the atomic response using both the frequency-dependent absorption cross section and a time-frequency approach based on the time-dependent dipole induced by the light fields. The latter approach can be used in cases when an ultrafast dressing pulse induces transient effects, and/or when the atom exchanges energy with multiple frequency components of the XUV field. We first characterize the dressed atom response by calculating the frequency-dependent absorption cross section for XUV energies between 20 and 24 eV for several dressing wavelengths between 400 and 2000 nm and intensities up to 10^12 W/cm^2. We find that for dressing wavelengths near 1600 nm, there is an Autler-Townes splitting of the 1s ---> 2p transition that can potentially lead to transparency for absorption of XUV light tuned to this transition. We study the effect of this XUV transparency in a macroscopic helium gas by incorporating the time-frequency approach into a solution of the coupled Maxwell-Schr\"odinger equations. We find rich temporal reshaping dynamics when a 61 fs XUV pulse resonant with the 1s ---> 2p transition propagates through a helium gas dressed by an 11 fs, 1600 nm laser pulse.<br />Comment: 13 pages, 8 figures, 1 table, RevTeX4, revised
- Subjects :
- Physics - Atomic Physics
Physics - Optics
Subjects
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. A 83, 013419 (2011) [12 pages]
- Publication Type :
- Report
- Accession number :
- edsarx.1010.4558
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevA.83.013419