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

arXiv:quant-ph/0103125 · Physical Review Letters

Polarization Instabilities in a Two-Photon Laser

Olivier Pfister, William J. Brown, Michael D. Stenner, Daniel J. Gauthier

Published May 14, 2001• 33 citations
arXivHTMLPDF

Abstract

We describe the operating characteristics of a new type of quantum oscillator that is based on a two-photon stimulated emission process. This two-photon laser consists of spin-polarized and laser-driven 39K atoms placed in a high-finesse transverse-mode-degenerate optical resonator and produces a beam with a power of approximately 0.2 microW at a wavelength of 770 nm. We observe complex dynamical instabilities of the state of polarization of the two-photon laser, which are made possible by the atomic Zeeman degeneracy. We conjecture that the laser could emit polarization-entangled twin beams if this degeneracy is lifted.

DOI
10.1103/physrevlett.86.4512

Related papers

Polarization dynamics of two-photon and cascade lasers in the presence of an arbitrarily directed magnetic field

Alexander M. Kul'minskii, Daniel J. Gauthier, Ramon A. Vilaseca +2 more

We study theoretically the polarization dynamics of a new type of quantum oscillator that is based on the two-photon stimulated emission process in the presence of a magnetic field of arbitrary orientation. Both cases of cascade (small intermediate-state atomic detuning) and two-photon (large atomic detuning) lasers are considered. The primary goal of this work is to investigate the origin of recently observed polarization instabilities in a two-photon laser (Pfister et al 2001 Phys. Rev. Lett. 86 4512) using a highly simplified model. It is found that the two-photon laser can emit linearly polarized radiation with its plane of polarization orthogonal to the direction of the magnetic field at small magnetic field strengths. It can also emit elliptically polarized radiation over a large range of magnetic field strengths and orientations. When the magnetic field deviates from a direction perpendicular to the laser cavity axis periodic instabilities can appear through a Hopf bifurcation. This dynamic regime could have contributed to the polarization instabilities observed in the experiment.

Journal of Optics B Quantum and Semiclassical Optics•Apr 24, 2003•1 citation

Experimental realization of a two-photon laser in strongly driven potassium atoms

Olivier Pfister, William J. Brown, Michael D. Stenner +1 more

Summary form only given. We present experimental evidence for novel quantum oscillators consisting of strongly driven potassium atoms contained in a high finesse optical resonator. These oscillators are based on two-photon stimulated emission, making their behavior and properties significantly different from conventional lasers, but making them harder to realize. The multi-level structure of alkali atoms is ideally suited for realizing such an oscillator since it offers a wealth of scattering processes that display strong resonant enhancement. Two-photon amplification arises from laser-driven resonant scattering between magnetic hyperfine levels. A novel configuration using different states of polarization and an orthogonal beam geometry allows discrimination between the numerous gain mechanisms.

Quantum Electronics and Laser Science Conference•Jan 20, 2003•1 citation

EXPERIMENTAL REALIZATION OF A TWO-PHOTON RAMAN LASER

William J. Brown

This thesis describes the development of a novel quantum oscillator known as a two-photon Raman laser. It is based on two-photon stimulated emission in strongly driven potassium atoms. Two-photon lasers were Þrst proposed in the 1960s, but only recently have such devices been experimentally realized. The two-photon Raman laser is an important step forward as it provides the Þrst oppurtunity to study the turn-on behavior, instabilities, and noise properties of a pure two-photon optical device. The necessary ingredients for a two-photon laser are a medium displaying two-photon laser beam ampliÞcation and an optical resonator. In my two-photon Raman laser the ampliÞcation arises from a multi-photon process in which state-prepared potassium atoms undergo two-photon Raman transitions. This ampliÞcation process was studied using a high-density, small-Doppler-width potassium atomic beam that was driven by a strong pump laser and probed by a weak probe laser. I observed two-photon Raman ampliÞcation for a range of pump laser frequencies, atomic beam

•Nov 1, 1999•2 citations

Stimulated entanglement: the onset of an entangled photon laser

Dirk Bouwmeester

We introduce the notion of laser-like operation for polarization entangled photons. The proposed device has a two-mode output which contains quantum correlations both between the polarization degree of freedom for particles in separate modes and between the photon numbers in the modes. The proposed device will operate in the new and virtually unexplored regime of many-particle entanglement. We present the design and provide experimental data in support of the main operation mechanism. In particular we show the generation of a rotational symmetric four-photon entangled state obtained by stimulated emission of the familiar antisymmetric two-particle Bell state. The produced states allow for novel quantum cryptography and quantum information protocols and for tests of spin-s Bell inequalities.

Optical Fiber Communication Conference•Jan 1, 2001•0 citations

Two-photon stimulated emission in laser-driven alkali-metal atoms using an orthogonal pump-probe geometry

Olivier Pfister, William J. Brown, Michael D. Stenner +1 more

We observe and analyze a two-photon continuous-wave optical gain mechanism designed for building a two-photon laser. The two-photon stimulated emission is spectrally isolated and resonantly enhanced using the multilevel structure of ${}^{39}\mathrm{K},$ in conjunction with an alternative interaction geometry involving orthogonal beams and polarizations. The observed two-photon laser beam amplification increases linearly with low input laser beam intensity, as expected, and saturates at a gain of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ at high intensity. A theoretical analysis of the observations is outlined.

Physical Review A•Dec 1, 1999•19 citations

Polarization-Controlled Single Photons

Tatjana Wilk, S. C. Webster, Holger Specht +2 more

Vacuum-stimulated Raman transitions are driven between two magnetic substates of a 87Rb atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatiotemporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.

arXiv:quant-ph/0610227•Physical Review Letters•Feb 5, 2007•122 citations
We describe the operating characteristics of a new type of quantum oscillator that is based on a two-photon stimulated emission process. This two-photon laser consists of spin-polarized and laser-driven 39K atoms placed in a high-finesse transverse-mode-degenerate optical resonator and produces a beam with a power of approximately 0.2 microW at a wavelength of 770 nm. We observe complex dynamical instabilities of the state of polarization of the two-photon laser, which are made possible by the atomic Zeeman degeneracy. We conjecture that the laser could emit polarization-entangled twin beams if this degeneracy is lifted.
We study theoretically the polarization dynamics of a new type of quantum oscillator that is based on the two-photon stimulated emission process in the presence of a magnetic field of arbitrary orientation. Both cases of cascade (small intermediate-state atomic detuning) and two-photon (large atomic detuning) lasers are considered. The primary goal of this work is to investigate the origin of recently observed polarization instabilities in a two-photon laser (Pfister et al 2001 Phys. Rev. Lett. 86 4512) using a highly simplified model. It is found that the two-photon laser can emit linearly polarized radiation with its plane of polarization orthogonal to the direction of the magnetic field at small magnetic field strengths. It can also emit elliptically polarized radiation over a large range of magnetic field strengths and orientations. When the magnetic field deviates from a direction perpendicular to the laser cavity axis periodic instabilities can appear through a Hopf bifurcation. This dynamic regime could have contributed to the polarization instabilities observed in the experiment.
Summary form only given. We present experimental evidence for novel quantum oscillators consisting of strongly driven potassium atoms contained in a high finesse optical resonator. These oscillators are based on two-photon stimulated emission, making their behavior and properties significantly different from conventional lasers, but making them harder to realize. The multi-level structure of alkali atoms is ideally suited for realizing such an oscillator since it offers a wealth of scattering processes that display strong resonant enhancement. Two-photon amplification arises from laser-driven resonant scattering between magnetic hyperfine levels. A novel configuration using different states of polarization and an orthogonal beam geometry allows discrimination between the numerous gain mechanisms.
This thesis describes the development of a novel quantum oscillator known as a two-photon Raman laser. It is based on two-photon stimulated emission in strongly driven potassium atoms. Two-photon lasers were Þrst proposed in the 1960s, but only recently have such devices been experimentally realized. The two-photon Raman laser is an important step forward as it provides the Þrst oppurtunity to study the turn-on behavior, instabilities, and noise properties of a pure two-photon optical device. The necessary ingredients for a two-photon laser are a medium displaying two-photon laser beam ampliÞcation and an optical resonator. In my two-photon Raman laser the ampliÞcation arises from a multi-photon process in which state-prepared potassium atoms undergo two-photon Raman transitions. This ampliÞcation process was studied using a high-density, small-Doppler-width potassium atomic beam that was driven by a strong pump laser and probed by a weak probe laser. I observed two-photon Raman ampliÞcation for a range of pump laser frequencies, atomic beam
We introduce the notion of laser-like operation for polarization entangled photons. The proposed device has a two-mode output which contains quantum correlations both between the polarization degree of freedom for particles in separate modes and between the photon numbers in the modes. The proposed device will operate in the new and virtually unexplored regime of many-particle entanglement. We present the design and provide experimental data in support of the main operation mechanism. In particular we show the generation of a rotational symmetric four-photon entangled state obtained by stimulated emission of the familiar antisymmetric two-particle Bell state. The produced states allow for novel quantum cryptography and quantum information protocols and for tests of spin-s Bell inequalities.
We observe and analyze a two-photon continuous-wave optical gain mechanism designed for building a two-photon laser. The two-photon stimulated emission is spectrally isolated and resonantly enhanced using the multilevel structure of 39K,{}^{39}\mathrm{K},39K, in conjunction with an alternative interaction geometry involving orthogonal beams and polarizations. The observed two-photon laser beam amplification increases linearly with low input laser beam intensity, as expected, and saturates at a gain of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ at high intensity. A theoretical analysis of the observations is outlined.
Vacuum-stimulated Raman transitions are driven between two magnetic substates of a 87Rb atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatiotemporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.