Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Dicke superradiance and stimulated electronic Raman scattering of indium

Santaram Chilukuri

Published Jul 1, 1996• 7 citations
Publisher

Abstract

Dicke superradiance (SR) and stimulated electronic Raman scattering (SERS) have been observed at 451.1 nm in atomic indium following optical excitation at the resonance line 410.2 nm. The SR and SERS characteristics have been studied. The coherent population trapping state was observed. The pump to Raman conversion efficiency is found to be up to 40% and a range of tunability of 30 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The SR and SERS processes have shown different optimum densities of indium atoms. \textcopyright{} 1996 The American Physical Society.

DOI
10.1103/physreva.54.908

Related papers

Stimulated electronic Raman scatterng in sodium vapor

Xiaofeng Han, Zhenguo Lu, Zuguang Ma +1 more

The observation of a stimulated electronic Raman scattering (SERS) on 3s–4s transition in sodium vapor pumped by a PTP dye laser is reported. Infrared output (Stokes) tunable from 2.38 μm to 2.65 μm has been obtained as the dye laser is tuned from 334.0 nm to 338.8 nm. Maximum photon conversion efficiency is about 30%.

AIP conference proceedings•Jan 1, 1987•0 citations

Saturation and tuning behavior of stimulated electronic Raman scattering

D. Cotter, D. Hanna

The saturation behavior of stimulated electronic Raman scattering (SERS) in atomic vapors is studied theoretically and experimentally. Limits to the SERS output energy are imposed by both pump depletion and saturation of the Raman transition. The effects of these on the performance of tunable infrared lasers based on SERS are examined.

IEEE Journal of Quantum Electronics•Mar 1, 1978•27 citations

Some investigations into stimulated electronic Raman scattering and related processes in atomic vapours

David Brian Hearn

Stimulated electronic Raman scattering, SERS, is a simple method of efficiently generating widely tunable infrared radiation. This work describes techniques by which the tuning capability of this process may be extended. To this end several schemes in Caesium and Barium vapours have been investigated. In Barium vapour two Raman transitions were studied using fixed frequency lasers. Poor performance of one of these transitions led to the application of biharmonic pumping or 'coherent Raman mixing' to enable generation of infrared light, and was the first observation of this process in an atomic vapour. This technique was subsequently used to generate infrared light from tunable dye laser light, which gave continuous tuning from 1.16µm to 1.5µm. The process was found to be limited by atomic saturation. The effect which saturation has on the generation efficiency is considered theoretically, and predicts quite accurately the observed tuning behaviour. Two methods aimed at reducing molecular absorption effects in SERS in alkali vapours were investigated. The techniques employed either laser excitation and dissociation of the molecules or a reduction in their ground state concentration by superheating of the vapour. Some degree of success was achieved in improving the available tuning from the 6s-7s transition in Caesium. However, the inclusion of the effect of collision broadening of atomic transitions into a calculation of the Raman threshold suggests that little further improvement can be obtained on this transition. A direct measurement of the Raman threshold power on the 6s-5d5/2 transition in Caesium gave excellent agreement with theoretical predictions based on collision broadening of this Raman transition. In addition, this work gave an insight into the role photoionization plays in increasing the threshold under certain circumstances. The analysis suggests that laser pulse duration and vapour column length are important in determining whether Raman threshold can be exceeded.

•Jan 1, 1982•0 citations

Stimulated Raman processes in metal vapours

W.H.W. Tuttlebee

Recent work has demonstrated the potential of stimulated electronic Raman scattering, SERS, as a tunable IR source. The current work has aimed at an extension of the performance of SERS in the two areas of tuning capability and narrower linewidth; to this end a variety of stimulated electronic Raman schemes have been investigated. Initially the theoretical background of SERS and of various possible competing processes is reviewed. The construction and performance of the dye lasers and heat pipe ovens used for the work are then described, followed by a presentation and discussion of the experimental work performed; this work falls into four main areas. Firstly the potential of pump and SERS feedback schemes to extend the tuning ranges of an existing alkali metal SERS system, Cs 6s-7s, has been investigated, under non-optimum conditions; results from this appear promising for future work. Secondly, we have demonstrated for the first time the possibility of obtaining a tunable IR output from a fifth order nonlinear process, stimulated hyper-Raman scattering, SHRS, in Na vapour. Various aspects of theory and behaviour of this process are described. The advantages of obtaining SERS from an excited initial state have been considered; preliminary results have proved disappointing and have led us to consider possible limiting mechanisms in such processes. Finally SERS in alkaline earths is considered; only few such schemes would appear to be viable for various reasons. One such scheme in Ba has however yielded a 0.2cm-1 system-limited SERS linewidth, a narrower SERS linewidth than has previously been attained; indications are that narrower linewidths still may be attainable, although further work will be necessary to verify this. These results also suggest that the optical Stark effect and power broadening have less influence on the Raman linewidth than has previously been thought.

•Dec 1, 1977•0 citations

Observation of superradiant Raman scattering in a Bose-Einstein condensate

Yutaka Yoshikawa, Toshiaki Sugiura, Yoshio Torii +1 more

We observed superradiant Raman scattering from a Bose-Einstein condensate irradiated by a single off-resonant light beam. Spontaneous mode selection of the scattered radiation turns probabilistic optical pumping into a stimulated Raman process, whereby the atoms are coherently transferred into a different hyperfine state. The population in the pumped state grew exponentially in time, demonstrating the emergence of bosonic stimulation in the optical pumping process.

Physical Review A•Apr 1, 2004•63 citations

Stimulated anti-Stokes Raman scattering in inverted atomic selenium

Raymond C. Y. Auyeung, D. G. Cooper, B. J. Feldman

The generation of 145.6-nm radiation by stimulated anti-Stokes Raman scattering in inverted atomic selenium was first reported by Ludewigt et al. 1 We have performed experimental studies of this process in similar excitation conditions, which allow us to compare some of the results in the two studies. The inverted population of the selenium (4p4)1S0 metastable state relative to the (4p4)3P0 state was prepared by photodissociation of COSe vapor using broadband 193-nm radiation from an ArF excimer laser. The pump beam at 205.1 nm was generated by the first-order Stokes shift in deuterium of narrowband (0.27-cm–1), 193-nm radiation from a separate, tunable ArF laser. The pump beam was tuned near the selenium (4p4)1S0–(4p35s)3P1 intermediate resonance to generate tunable, coherent radiation at 145.6 nm. We have studied the process in a variety of experimental conditions. Factors affecting the conversion efficiency and tunability include the initial COSe pressure, the intensities and relative timing of the photolyzing and pump beams, and the presence of buffer gases. The experimental results are compared with theoretical calculations based on a recently developed three-level model2 which incorporates Doppler broadening and arbitrary decay times.

Annual Meeting Optical Society of America•Jan 1, 1989•0 citations
Dicke superradiance (SR) and stimulated electronic Raman scattering (SERS) have been observed at 451.1 nm in atomic indium following optical excitation at the resonance line 410.2 nm. The SR and SERS characteristics have been studied. The coherent population trapping state was observed. The pump to Raman conversion efficiency is found to be up to 40% and a range of tunability of 30 cm\ensuremath−1{\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}cm\ensuremath−1. The SR and SERS processes have shown different optimum densities of indium atoms. \textcopyright{} 1996 The American Physical Society.
Stimulated electronic Raman scattering, SERS, is a simple method of efficiently generating widely tunable infrared radiation. This work describes techniques by which the tuning capability of this process may be extended. To this end several schemes in Caesium and Barium vapours have been investigated. In Barium vapour two Raman transitions were studied using fixed frequency lasers. Poor performance of one of these transitions led to the application of biharmonic pumping or 'coherent Raman mixing' to enable generation of infrared light, and was the first observation of this process in an atomic vapour. This technique was subsequently used to generate infrared light from tunable dye laser light, which gave continuous tuning from 1.16µm to 1.5µm. The process was found to be limited by atomic saturation. The effect which saturation has on the generation efficiency is considered theoretically, and predicts quite accurately the observed tuning behaviour. Two methods aimed at reducing molecular absorption effects in SERS in alkali vapours were investigated. The techniques employed either laser excitation and dissociation of the molecules or a reduction in their ground state concentration by superheating of the vapour. Some degree of success was achieved in improving the available tuning from the 6s-7s transition in Caesium. However, the inclusion of the effect of collision broadening of atomic transitions into a calculation of the Raman threshold suggests that little further improvement can be obtained on this transition. A direct measurement of the Raman threshold power on the 6s-5d5/2 transition in Caesium gave excellent agreement with theoretical predictions based on collision broadening of this Raman transition. In addition, this work gave an insight into the role photoionization plays in increasing the threshold under certain circumstances. The analysis suggests that laser pulse duration and vapour column length are important in determining whether Raman threshold can be exceeded.
Recent work has demonstrated the potential of stimulated electronic Raman scattering, SERS, as a tunable IR source. The current work has aimed at an extension of the performance of SERS in the two areas of tuning capability and narrower linewidth; to this end a variety of stimulated electronic Raman schemes have been investigated. Initially the theoretical background of SERS and of various possible competing processes is reviewed. The construction and performance of the dye lasers and heat pipe ovens used for the work are then described, followed by a presentation and discussion of the experimental work performed; this work falls into four main areas. Firstly the potential of pump and SERS feedback schemes to extend the tuning ranges of an existing alkali metal SERS system, Cs 6s-7s, has been investigated, under non-optimum conditions; results from this appear promising for future work. Secondly, we have demonstrated for the first time the possibility of obtaining a tunable IR output from a fifth order nonlinear process, stimulated hyper-Raman scattering, SHRS, in Na vapour. Various aspects of theory and behaviour of this process are described. The advantages of obtaining SERS from an excited initial state have been considered; preliminary results have proved disappointing and have led us to consider possible limiting mechanisms in such processes. Finally SERS in alkaline earths is considered; only few such schemes would appear to be viable for various reasons. One such scheme in Ba has however yielded a 0.2cm-1 system-limited SERS linewidth, a narrower SERS linewidth than has previously been attained; indications are that narrower linewidths still may be attainable, although further work will be necessary to verify this. These results also suggest that the optical Stark effect and power broadening have less influence on the Raman linewidth than has previously been thought.
The generation of 145.6-nm radiation by stimulated anti-Stokes Raman scattering in inverted atomic selenium was first reported by Ludewigt et al. 1 We have performed experimental studies of this process in similar excitation conditions, which allow us to compare some of the results in the two studies. The inverted population of the selenium (4p4)1S0 metastable state relative to the (4p4)3P0 state was prepared by photodissociation of COSe vapor using broadband 193-nm radiation from an ArF excimer laser. The pump beam at 205.1 nm was generated by the first-order Stokes shift in deuterium of narrowband (0.27-cm–1), 193-nm radiation from a separate, tunable ArF laser. The pump beam was tuned near the selenium (4p4)1S0–(4p35s)3P1 intermediate resonance to generate tunable, coherent radiation at 145.6 nm. We have studied the process in a variety of experimental conditions. Factors affecting the conversion efficiency and tunability include the initial COSe pressure, the intensities and relative timing of the photolyzing and pump beams, and the presence of buffer gases. The experimental results are compared with theoretical calculations based on a recently developed three-level model2 which incorporates Doppler broadening and arbitrary decay times.