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 Experimental and Theoretical Physics

Quantum-dot microlaser operating on the whispering gallery mode—A source of squeezed (sub-Poissonian) light

A. V. Kozlovsky, Anatoly N. Oraevsky

Published Nov 1, 2000• 2 citations
Publisher

Abstract

The reduced density matrix method is used to calculate the quantum-statistical properties of the radiation of a quantum-dot laser operating on the whispering gallery mode of a dielectric microsphere. It is shown that under the conditions of strong coupling between the quantum dot and an electromagnetic field the radiation of such a laser can be in a nonclassical (sub-Poissonian) state. The laser scheme considered is characterized by an extremely low lasing threshold and a small number of saturation photons, as result of which lasing is possible with close to zero population inversion of the working levels, if g ≫ P ≫ γ ≫ Γ, where g is the field-matter interaction constant, P is the pumping rate, γ is the loss rate of the resonator, and Γ is the spontaneous emission rate. The largest squeezing inside the resonator-microsphere (the Fano factor F = 0.75) obtains for g ≫ P ≫ γ ≫ Γ, and the greatest squeezing in the fluctuation spectrum outside the resonator [V(ω = 0) ≈ 0.25] occurs for g ∼ P ∼ γ ≫ Γ, and in this case a substantial deviation of the photon number statistics of the radiation leaving the resonator from the Poissonian statistics is observed.

DOI
10.1134/1.1334983

Related papers

Quantum Langevin theory of whispering-gallery-mode microsphere laser

Chai Jin-hua, Lu Yi-Qun, Leung Pui-tang

A quantum Langevin theory of whispering-gallery-mode microsphere laser theory is developed. The linear and nonlinear analysis are made for laser operation below and above the threshold. In these analysis, corresponding to the specific property of microsphere, the effect of inversion fluctuation is treated. The coherence functions of laser field are calculated, and the intensity, the amplitude fluctuation and the linewidth of the field are obtained, which are connected with the enhancement factor of whispering-gallery-mode microsphere. It is shown that the strong couple and strong pumping are useful for the amplification of intensity and the decrease of linewidth below the threshold. It is also shown that, for the laser action above threshold, the variances of photon number and the linewidth of internal field are related to the enhancement factor and the square of the enhancement factor, respectively.

Chinese Physics•Apr 1, 2000•0 citations

Sub-Poissonian radiation of a one-atom two-level laser with incoherent pumping

A. V. Kozlovskiĭ, А. Н. Ораевский

The quantum statistical properties of the radiation of a one-atom two-level laser with incoherent pumping are analyzed. Solution of the Liouville equation for the density operator in the basis of Fock states shows that stationary radiation from a single-mode laser with incoherent pumping can be in a squeezed (sub-Poissonian) stationary state if the rate of spontaneous decay is lower than the rate of cavity losses and the pump rate. Inside the cavity the Fano factor reaches F =0.85 (15% squeezing). Multiple squeezing ( F =0.19) is possible in the transient lasing regime. Significant squeezing obtains at the cavity output; the spectral Fano factor at zero frequency is 0.36 under optimal conditions.

Journal of Experimental and Theoretical Physics•Apr 1, 1999•12 citations

Generation of squeezed (sub-Poissonian) light by a multimode laser

A. V. Kozlovskiĭ

Theoretical and experimental results of investigations into the quantum noise of multimode laser radiation are considered. The feasibility of generating light with a photon-number-squeezed (sub-Poissonian) photon distribution by a multimode laser with a homogeneously broadened line is analyzed. The conditions of noisy and noiseless (regular) pumping are considered. Photon-number fluctuations of the net laser radiation summed over all generated modes are calculated in the approximation of equidistant equal modes, as are photon-number fluctuations in an individual mode inside and outside the resonator. Output-radiation noise spectra and photon-number fluctuations are calculated for solid-state (neodymium glass, Nd:YAG) and semiconductor lasers. Theoretical results are compared with a number of experimental data obtained for semiconductor lasers in recent years.

Physics-Uspekhi•Dec 31, 2007•3 citations

Dynamics of the excitations of a quantum dot in a microcavity

J. I. Perea, Diego Porras, C. Tejedor

We study the dynamics of a quantum dot embedded in a three-dimensional microcavity in the strong coupling regime in which the quantum dot exciton has an energy close to the frequency of a confined cavity mode. Under the continuous pumping of the system, the confined electron and hole can recombine either by spontaneous emission through a leaky mode or by stimulated emission of a cavity mode that can escape from the cavity. The numerical integration of a master equation including all these effects gives the dynamics of the density matrix. By using the quantum regression theorem, we compute the first- and second-order coherence functions required to calculate the photon statistics and the spectrum of the emitted light. Our main result is the determination of a range of parameters in which a state of cavity modes with Poissonian or sub-Poissonian (nonclassical) statistics can be built up within the microcavity. Depending on the relative values of pumping and rate of stimulated emission, either one or two peaks close to the excitation energy of the dot and/or to the natural frequency of the cavity are observed in the emission spectrum. The physics behind these results is discussed.

arXiv:cond-mat/0310570•Physical Review B•Sep 9, 2004•60 citations

Lasing threshold for whispering-gallery-mode microsphere lasers

Ying Wu, P. T. Leung

The analytical expression for the lasing threshold for whispering-gallery-mode microsphere lasers under the strong-coupling condition is obtained by solving a quasi-three-level quantized model. It explicitly displays the dependence of the lasing threshold on the cavity radius, the homogeneous linewidth, the quality factors and linewidths of the relevant cavity modes.

Physical Review A•Jul 1, 1999•82 citations

Single-mode amplitude squeezing in a semiconductor laser at 780 nm

Ya. A. Fofanov, I. V. Sokolov

The problem of the creation of a sub-Poissonian radiation source on the basis of a semiconductor laser with an external cavity is considered, which operates, from the viewpoint of quantum optics, in the single-mode regime. The conditions of the generation of sub-Poissonian radiation, under which the whole set of sub-threshold modes, including the nearest modes of the external (long) cavity, is completely suppressed at room temperature, were experimentally revealed and theoretically studied. Single-frequency low-noise lasing is of interest not only for the creation of nonclassical light sources, but also for sensitive spectroscopic applications in the classical domain.

Optics and Spectroscopy•Oct 1, 2001•4 citations
The reduced density matrix method is used to calculate the quantum-statistical properties of the radiation of a quantum-dot laser operating on the whispering gallery mode of a dielectric microsphere. It is shown that under the conditions of strong coupling between the quantum dot and an electromagnetic field the radiation of such a laser can be in a nonclassical (sub-Poissonian) state. The laser scheme considered is characterized by an extremely low lasing threshold and a small number of saturation photons, as result of which lasing is possible with close to zero population inversion of the working levels, if g ≫ P ≫ γ ≫ Γ, where g is the field-matter interaction constant, P is the pumping rate, γ is the loss rate of the resonator, and Γ is the spontaneous emission rate. The largest squeezing inside the resonator-microsphere (the Fano factor F = 0.75) obtains for g ≫ P ≫ γ ≫ Γ, and the greatest squeezing in the fluctuation spectrum outside the resonator [V(ω = 0) ≈ 0.25] occurs for g ∼ P ∼ γ ≫ Γ, and in this case a substantial deviation of the photon number statistics of the radiation leaving the resonator from the Poissonian statistics is observed.
A quantum Langevin theory of whispering-gallery-mode microsphere laser theory is developed. The linear and nonlinear analysis are made for laser operation below and above the threshold. In these analysis, corresponding to the specific property of microsphere, the effect of inversion fluctuation is treated. The coherence functions of laser field are calculated, and the intensity, the amplitude fluctuation and the linewidth of the field are obtained, which are connected with the enhancement factor of whispering-gallery-mode microsphere. It is shown that the strong couple and strong pumping are useful for the amplification of intensity and the decrease of linewidth below the threshold. It is also shown that, for the laser action above threshold, the variances of photon number and the linewidth of internal field are related to the enhancement factor and the square of the enhancement factor, respectively.
The quantum statistical properties of the radiation of a one-atom two-level laser with incoherent pumping are analyzed. Solution of the Liouville equation for the density operator in the basis of Fock states shows that stationary radiation from a single-mode laser with incoherent pumping can be in a squeezed (sub-Poissonian) stationary state if the rate of spontaneous decay is lower than the rate of cavity losses and the pump rate. Inside the cavity the Fano factor reaches F =0.85 (15% squeezing). Multiple squeezing ( F =0.19) is possible in the transient lasing regime. Significant squeezing obtains at the cavity output; the spectral Fano factor at zero frequency is 0.36 under optimal conditions.
Theoretical and experimental results of investigations into the quantum noise of multimode laser radiation are considered. The feasibility of generating light with a photon-number-squeezed (sub-Poissonian) photon distribution by a multimode laser with a homogeneously broadened line is analyzed. The conditions of noisy and noiseless (regular) pumping are considered. Photon-number fluctuations of the net laser radiation summed over all generated modes are calculated in the approximation of equidistant equal modes, as are photon-number fluctuations in an individual mode inside and outside the resonator. Output-radiation noise spectra and photon-number fluctuations are calculated for solid-state (neodymium glass, Nd:YAG) and semiconductor lasers. Theoretical results are compared with a number of experimental data obtained for semiconductor lasers in recent years.
We study the dynamics of a quantum dot embedded in a three-dimensional microcavity in the strong coupling regime in which the quantum dot exciton has an energy close to the frequency of a confined cavity mode. Under the continuous pumping of the system, the confined electron and hole can recombine either by spontaneous emission through a leaky mode or by stimulated emission of a cavity mode that can escape from the cavity. The numerical integration of a master equation including all these effects gives the dynamics of the density matrix. By using the quantum regression theorem, we compute the first- and second-order coherence functions required to calculate the photon statistics and the spectrum of the emitted light. Our main result is the determination of a range of parameters in which a state of cavity modes with Poissonian or sub-Poissonian (nonclassical) statistics can be built up within the microcavity. Depending on the relative values of pumping and rate of stimulated emission, either one or two peaks close to the excitation energy of the dot and/or to the natural frequency of the cavity are observed in the emission spectrum. The physics behind these results is discussed.
The problem of the creation of a sub-Poissonian radiation source on the basis of a semiconductor laser with an external cavity is considered, which operates, from the viewpoint of quantum optics, in the single-mode regime. The conditions of the generation of sub-Poissonian radiation, under which the whole set of sub-threshold modes, including the nearest modes of the external (long) cavity, is completely suppressed at room temperature, were experimentally revealed and theoretically studied. Single-frequency low-noise lasing is of interest not only for the creation of nonclassical light sources, but also for sensitive spectroscopic applications in the classical domain.