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

Journal of physics. A, Proceedings of the Physical Society. General

Amplified spontaneous emission I. The threshold condition

G I Peters, L. Allen

Published Mar 1, 1971• 108 citations
Publisher

Abstract

The threshold condition for the onset of amplified spontaneous emission is derived and experimentally verified in the 3.39 mu m He-Ne and the 0.614 mu m Ne systems. A short discussion is given concerning the confusion between this type of radiation and superradiance.
DOI
10.1088/0305-4470/4/2/009

Related papers

Amplified spontaneous emission III. Intensity and saturation

L. Allen, G I Peters

For pt. II see abstr. A35654 of 1971. A theory is developed to account for the intensity of ASE as a function of the length and diameter of the amplifying medium and of its inversion density. Detailed results are presented from a study of the 3.39 mu m transition in He-Ne which verify the theory. The theory is also shown to fit the experimental data obtained from the 0.337 mu m transition in N 2 .

Journal of physics. A, Proceedings of the Physical Society. General•Jul 1, 1971•50 citations

Amplified spontaneous emission. IV. Beam divergence and spatial coherence

G I Peters, L. Allen

For pt. III see abstr. A54492 of 1971. The origins of beam divergence in amplified spontaneous emission are discussed and theoretical models are developed to predict what their effect would be in real systems. The divergence of the beam is experimentally investigated for the 3.39 mu m He-Ne and the 0.614 mu m Ne systems and compared with the theories. Good agreement is achieved in pure neon for a theory which depends upon the parametric relationship between intensity and length of active medium. In the case of He-Ne although the theory gives the correct qualitative prediction, the absolute magnitude of the effect is wrong by a factor of about 1.7. Measurements of the degree of spatial coherence as a function of length and inversion density of the medium and for the variation of spatial coherence across the tube for a given length and inversion density of medium, are presented for the neon system.

Journal of physics. A, Proceedings of the Physical Society. General•Apr 1, 1972•30 citations

Collective spontaneous emission (Dicke superradiance)

Anatolii V Andreev, Vladimir I Emel'yanov, Yu A Il'inskiĭ

The present state of theoretical and experimental research on collective spontaneous emission (superradiance) in a system of radiators (atoms, molecules, or nuclei) is reviewed. The distinction between superradiance and the amplification of spontaneous emission is discussed. There is also a discussion of conditions under which the effect can be observed and of various theoretical methods for describing superradiance: the quantum single-mode and multimode models and the semiclassical approach. Theoretical papers on superradiance in systems with dimensions smaller than the wavelength of the radiation and also in extended systems are reviewed. It is shown that superradiance may occur in weakly amplifying media. A situation in which the superradiance is oscillatory is described. The possible use of superradiance to generate coherent emission in the x-ray and ? ranges is discussed. The superradiance accompanying Raman scattering of light in atomic and molecular media is studied. The theoretical results are compared with experimental observations of superradiance in the optical range. In an appendix, the nature of the phase transition in a system of radiators interacting through an electromagnetic field is discussed.

Soviet Physics Uspekhi•Aug 31, 1980•143 citations

Amplified spontaneous emission. II. The connection with laser theory

L. Allen, G I Peters

A simple relationship is derived between L c the critical length for amplified spontaneous emission, and L T , the threshold length of gas that must be excited for laser action to occur in a cavity of loss delta l . The relationship is experimentally verified and the semiclassical laser theory of Stenholm and Lamb is re-verified in a new way.

Journal of physics. A, Proceedings of the Physical Society. General•May 1, 1971•37 citations

Amplified Spontaneous Emission and External Signal Amplification in an Inverted Medium

L. Allen, G I Peters

An improved version of the theory of amplified spontaneous emission (ASE) is presented and shown to be satisfied by experimental data obtained using the 3.39-\ensuremath{\mu}m transition of He-Ne. The new approach allows the effect of an external signal injected at one end of the system to be investigated and its influence on both the positive-going and negative-going waves to be calculated for He-Ne. A special case occurs when the injected signal is replaced by a mirror which reflects the negative-going wave back into the medium and the theory of this commonly occurring laboratory system is experimentally verified at 3.39 \ensuremath{\mu}m. The treatment allows the importance of the interaction between spontaneous and stimulated emission to be considered. The beam divergence predicted by the theory is evaluated and compared with experiment. The spectral distribution for a pure ASE system is considered, as is the distribution of inversion which results from the positive- and negative-going waves and which is shown to have minima at the medium extremities. Finally the implications of this work for the problem of interstellar OH emission is considered.

Physical Review A•Oct 1, 1973•109 citations

ON THE GENERATION OF RADIATION OF DIFFERENT NATURES

Evgen Poklonskiy, Volodymyr M. Kuklin

The paper discusses the nature and consequences of competition between different types of radiation - spontaneous and induced, as well as superradiation in quantum and classical systems. Near the new threshold for the generation of stimulated radiation, t

European Science•Jun 30, 2022•0 citations
For pt. III see abstr. A54492 of 1971. The origins of beam divergence in amplified spontaneous emission are discussed and theoretical models are developed to predict what their effect would be in real systems. The divergence of the beam is experimentally investigated for the 3.39 mu m He-Ne and the 0.614 mu m Ne systems and compared with the theories. Good agreement is achieved in pure neon for a theory which depends upon the parametric relationship between intensity and length of active medium. In the case of He-Ne although the theory gives the correct qualitative prediction, the absolute magnitude of the effect is wrong by a factor of about 1.7. Measurements of the degree of spatial coherence as a function of length and inversion density of the medium and for the variation of spatial coherence across the tube for a given length and inversion density of medium, are presented for the neon system.
The present state of theoretical and experimental research on collective spontaneous emission (superradiance) in a system of radiators (atoms, molecules, or nuclei) is reviewed. The distinction between superradiance and the amplification of spontaneous emission is discussed. There is also a discussion of conditions under which the effect can be observed and of various theoretical methods for describing superradiance: the quantum single-mode and multimode models and the semiclassical approach. Theoretical papers on superradiance in systems with dimensions smaller than the wavelength of the radiation and also in extended systems are reviewed. It is shown that superradiance may occur in weakly amplifying media. A situation in which the superradiance is oscillatory is described. The possible use of superradiance to generate coherent emission in the x-ray and ? ranges is discussed. The superradiance accompanying Raman scattering of light in atomic and molecular media is studied. The theoretical results are compared with experimental observations of superradiance in the optical range. In an appendix, the nature of the phase transition in a system of radiators interacting through an electromagnetic field is discussed.
An improved version of the theory of amplified spontaneous emission (ASE) is presented and shown to be satisfied by experimental data obtained using the 3.39-\ensuremath{\mu}m transition of He-Ne. The new approach allows the effect of an external signal injected at one end of the system to be investigated and its influence on both the positive-going and negative-going waves to be calculated for He-Ne. A special case occurs when the injected signal is replaced by a mirror which reflects the negative-going wave back into the medium and the theory of this commonly occurring laboratory system is experimentally verified at 3.39 \ensuremath{\mu}m. The treatment allows the importance of the interaction between spontaneous and stimulated emission to be considered. The beam divergence predicted by the theory is evaluated and compared with experiment. The spectral distribution for a pure ASE system is considered, as is the distribution of inversion which results from the positive- and negative-going waves and which is shown to have minima at the medium extremities. Finally the implications of this work for the problem of interstellar OH emission is considered.