• Open Access

Quantum Amplification by Superradiant Emission of Radiation

Anatoly A. Svidzinsky, Luqi Yuan, and Marlan O. Scully
Phys. Rev. X 3, 041001 – Published 8 October 2013

Abstract

A laser generates light through stimulated emission of radiation and requires population inversion. Quantum interference can yield lasing without inversion. However, such phase-sensitive quantum amplification still requires some atomic population in the excited state. Here, we present a new kind of quantum amplifier based on collective superradiant emission which does not need any population in the excited state. We show that parametric resonance between the driving (e.g., infrared) field and collective superradiant oscillations of the atomic polarization can yield light amplification at high (e.g., XUV) frequencies. To achieve gain, one must suppress a time-dependent Stark shift caused by the driving field. The resulting superradiant amplifier is many orders of magnitude more efficient than the usual nonlinear multiphoton excitation and holds promise for a new kind of generator of high-frequency coherent radiation. In addition to a detailed analytical analysis, confirmed by numerical simulations, we provide a physically appealing explanation of the quantum amplification by superradiant emission of radiation (QASER) operation in terms of coupled classical oscillators. We also present an experiment that demonstrates the QASER amplification mechanism in an electronic circuit, which, to the best of our knowledge, is the first experimental demonstration of the difference combination resonance.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
8 More
  • Received 18 June 2013

DOI:https://doi.org/10.1103/PhysRevX.3.041001

This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Authors & Affiliations

Anatoly A. Svidzinsky1,2, Luqi Yuan1,2, and Marlan O. Scully1,2,3

  • 1Texas A&M University, College Station, Texas 77843, USA
  • 2Princeton University, Princeton, New Jersey 08544, USA
  • 3Baylor University, Waco, Texas 76706, USA

Popular Summary

Usually, a laser works on the basis of a population inversion: Instead of populating the different energy levels according to the thermal-equilibrium distribution, more members of the system (atoms, molecules, etc.) must be excited to an upper state relative to a lower level. This inversion allows light to be amplified by stimulated emission of photons. An exception to this is lasing achieved by creating quantum interference between different transitions; however, light amplification by this method still requires a population of excited energy levels. In this paper, we propose a new kind of quantum amplifier called a QASER (quantum amplification by superradiant emission of radiation) that requires no population in the excited state.

This amplification mechanism is based on superradiant emission, which is a collective response of an ensemble of atoms to a common driving light field. The coupled light-atom system has many collective modes of oscillation. Our calculations show that when the (low) frequency of the driving field matches the frequency difference between two close high-frequency modes of oscillation, a novel resonance phenomenon occurs and leads to amplified emission of coherent radiation at a frequency much higher than the driving frequency. To achieve light amplification, one must suppress the time-dependent shift of energy levels caused by the driving field. By conducting analog experiments with an electronic circuit that oscillates at much higher frequencies than the input voltage, we have demonstrated the principle of resonance and amplification underlying the QASER in the radio-frequency region.

If this principle can be demonstrated in an atomic system collectively interacting with light, the QASER could become a new source of coherent extreme ultraviolet or x-ray radiation.

Key Image

Article Text

Click to Expand

References

Click to Expand
Issue

Vol. 3, Iss. 4 — October - December 2013

Subject Areas
Reuse & Permissions
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review X

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 3.0 License. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×