Amplification of Spontaneous Emission from Doubly Excited He Atoms
We have observed amplification of weak fluorescence from He atoms in the 3a ^{1}P^{o} autoionizing state, which decay by spontaneous emission of 40.74 eV photons in one out of 1600 cases. On average, a 4.1±1.6% conversion of 63.67 eV photons was detected in the forward direction at 20 μJ pump pulse energy and 40 mbar He gas pressure. A comparison with state-of-the-art theoretical simulations shows an unexpected spectral line shift at high gas pressure that is ascribed to transient molecular and electron scattering effects.
Authors
- Emiliano Principi (ORCID: https://orcid.org/0000-0002-7508-462X)
- Marcello Coreno (ORCID: https://orcid.org/0000-0003-4376-808X)
- K. Bučar (ORCID: https://orcid.org/0000-0002-1602-5064)
- Marija Krstulović (ORCID: https://orcid.org/0000-0002-2942-3061)
- Laura Foglia (ORCID: https://orcid.org/0000-0002-2218-3886)
- C. Vozzi (ORCID: https://orcid.org/0000-0002-0212-0191)
- Anna G. Ciriolo (ORCID: https://orcid.org/0000-0003-1189-329X)
- A. Mihelič (ORCID: https://orcid.org/0000-0002-2292-4832)
- Gabriele Bonano (ORCID: https://orcid.org/0009-0004-7024-7591)
- Špela Krušič (ORCID: https://orcid.org/0000-0002-4680-2573)
- Roberto Osellame (ORCID: https://orcid.org/0000-0002-4457-9902)
- Andrei Benediktovitch (ORCID: https://orcid.org/0000-0001-6599-354X)
- Zeinab Ebrahimpour (ORCID: https://orcid.org/0000-0003-4634-7272)
- Riccardo Mincigrucci (ORCID: https://orcid.org/0000-0001-6343-6256)
- Kevin C. Prince (ORCID: https://orcid.org/0000-0002-5416-7354)
- Ettore Paltanin (ORCID: https://orcid.org/0009-0007-8490-5884)
- Alberto Simoncig (ORCID: https://orcid.org/0000-0002-4471-5927)
- Rebeca Martìnez Vàzquez (ORCID: https://orcid.org/0000-0001-8728-5819)
- Carlo Callegari (ORCID: https://orcid.org/0000-0001-5491-7752)
- M. Žitnik (ORCID: https://orcid.org/0000-0002-7823-200X)
- J. Turnšek (ORCID: https://orcid.org/0009-0000-6206-4024)
Institutions
- University of Ljubljana (SI)
- Charles University (CZ)
- Deutsches Elektronen-Synchrotron DESY (DE)
- Elettra-Sincrotrone Trieste S.C.p.A. (IT)
- Jožef Stefan Institute (SI)
- Center for Biomolecular Nanotechnologies (IT)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-08-26
- DOI
- https://doi.org/10.1103/mg5s-xvct
- Primary Topic
- Cold Atom Physics and Bose-Einstein Condensates
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Laserlab-Europe
- National Science Council
- Javna Agencija za Raziskovalno Dejavnost RS
- Horizon 2020 Framework Programme
- Horizon 2020