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Title: Femtosecond induced transparency and absorption in the extremeultraviolet by coherent coupling of the He 2s2p (1Po) and 2p2 (1Se)double excitation states with 800 nm light

Abstract

Femtosecond high-order harmonic transient absorption spectroscopy is used to observe electromagnetically induced transparency-like behavior as well as induced absorption in the extreme ultraviolet by laser dressing of the He 2s2p ({sup 1}P{sup 0}) and 2p{sup 2} ({sup 1}S{sup e}) double excitation states with an intense 800 nm field. Probing in the vicinity of the 1s{sup 2} {yields} 2s2p transition at 60.15 eV reveals the formation of an Autler-Townes doublet due to coherent coupling of the double excitation states. Qualitative agreement with the experimental spectra is obtained only when optical field ionization of both double excitation states into the N = 2 continuum is included in the theoretical model. Because the Fano q-parameter of the unperturbed probe transition is finite, the laser-dressed He atom exhibits both enhanced transparency and absorption at negative and positive probe energy detunings, respectively.

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Basic EnergySciences
OSTI Identifier:
932705
Report Number(s):
LBNL-63683
Journal ID: ISSN 0301-0104; CMPHC2; R&D Project: 401001; BnR: KC0301020; TRN: US0803651
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemical Physics; Journal Volume: 0; Journal Issue: 0; Related Information: Journal Publication Date: 0
Country of Publication:
United States
Language:
English
Subject:
74; ABSORPTION; ABSORPTION SPECTROSCOPY; ATOMS; EXCITATION; HARMONICS; IONIZATION; LASERS; PROBES; SPECTRA; TRANSIENTS

Citation Formats

Loh, Z.-H., Greene, C.H., and Leone, S.R.. Femtosecond induced transparency and absorption in the extremeultraviolet by coherent coupling of the He 2s2p (1Po) and 2p2 (1Se)double excitation states with 800 nm light. United States: N. p., 2007. Web.
Loh, Z.-H., Greene, C.H., & Leone, S.R.. Femtosecond induced transparency and absorption in the extremeultraviolet by coherent coupling of the He 2s2p (1Po) and 2p2 (1Se)double excitation states with 800 nm light. United States.
Loh, Z.-H., Greene, C.H., and Leone, S.R.. Wed . "Femtosecond induced transparency and absorption in the extremeultraviolet by coherent coupling of the He 2s2p (1Po) and 2p2 (1Se)double excitation states with 800 nm light". United States. doi:. https://www.osti.gov/servlets/purl/932705.
@article{osti_932705,
title = {Femtosecond induced transparency and absorption in the extremeultraviolet by coherent coupling of the He 2s2p (1Po) and 2p2 (1Se)double excitation states with 800 nm light},
author = {Loh, Z.-H. and Greene, C.H. and Leone, S.R.},
abstractNote = {Femtosecond high-order harmonic transient absorption spectroscopy is used to observe electromagnetically induced transparency-like behavior as well as induced absorption in the extreme ultraviolet by laser dressing of the He 2s2p ({sup 1}P{sup 0}) and 2p{sup 2} ({sup 1}S{sup e}) double excitation states with an intense 800 nm field. Probing in the vicinity of the 1s{sup 2} {yields} 2s2p transition at 60.15 eV reveals the formation of an Autler-Townes doublet due to coherent coupling of the double excitation states. Qualitative agreement with the experimental spectra is obtained only when optical field ionization of both double excitation states into the N = 2 continuum is included in the theoretical model. Because the Fano q-parameter of the unperturbed probe transition is finite, the laser-dressed He atom exhibits both enhanced transparency and absorption at negative and positive probe energy detunings, respectively.},
doi = {},
journal = {Chemical Physics},
number = 0,
volume = 0,
place = {United States},
year = {Wed Aug 01 00:00:00 EDT 2007},
month = {Wed Aug 01 00:00:00 EDT 2007}
}