Collective Effects of Laser-Driven Cold Atoms in an Optical Cavity

We report on the observation of a new magic frequency within the hyperfine structure of the D2 line of ${}^{87}$ Rb atoms at which the scattering of light into a high-finesse cavity is suppressed by an interplay between quantum interference and the strong collective coupling of atoms to the cavity. Scattering from a cloud of laser-driven cold atoms into the cavity was measured in a polarization sensitive way. We have found that both the Rayleigh and Raman scattering processes into the near-resonant cavity modes are extinguished at 185 MHz below the F=2 $\leftrightarrow$ F'=3 transition frequency. This coincidence together with the shape of the observed spectral dip imply that the effect relies on a quantum interference in the polariton excitations of the strongly coupled combined atom-photon system. We have also demonstrated the existence of a magic frequency around -506 MHz, where only the Raman scattering is suppressed due to a quantum interference effect at the single-atom level.We report on the observation of a new magic frequency within the hyperfine structure of the D2 line of ${}^{87}$Rb atoms at which the scattering of light into a high-finesse cavity is suppressed by an interplay between quantum interference and the strong collective coupling of atoms to the cavity. Scattering from a cloud of laser-driven cold atoms into the cavity was measured in a polarization sensitive way. We have found that both the Rayleigh and Raman scattering processes into the near-resonant cavity modes are extinguished at 185 MHz below the F=2$\leftrightarrow$F'=3 transition frequency. This coincidence together with the shape of the observed spectral dip imply that the effect relies on a quantum interference in the polariton excitations of the strongly coupled combined atom-photon system. We have also demonstrated the existence of a magic frequency around -506 MHz, where only the Raman scattering is suppressed due to a quantum interference effect at the single-atom level.

quant-pharXiv:2601.08978Jan 15, 20260 citations

Collective atomic motion and spin dynamics in a driven optical cavity

Dan Stamper-Kurn

Bulletin of the American Physical SocietyMay 25, 20160 citations

Optical nonlinear dynamics with cold atoms in a cavity

Astrid Lambrecht, E. Giacobino, Jean-Michel Courty

arXiv:quant-ph/9801054Optics CommunicationsMar 1, 199540 citations

Gain, amplification, and lasing in a driven atom-cavity system

Arun Bahuleyan, V. R. Thakar, V. I. Gokul +3 more

Cold atoms coupled to an optical cavity provide an ideal platform for creating lasers without conventional population inversion. Such lasers can generate very high spectral purity, and the output can be precisely controlled by varying the atom-drive or atom-cavity parameters. In this letter, we report experimental observation of gain, amplification, and self-lasing within a continuously operated 85 Rb magneto-optic trap (MOT), in the collective strong coupling regime of the atom-cavity system. The presence of MOT cooling lasers significantly alters the transmission properties of the cavity, and gain is observed in one of the vacuum Rabi peaks. The system makes a transition from an amplifying medium to a self-sustained laser as the MOT parameters are tuned. The underlying lasing mechanism is shown to be Mollow gain in the driven atomic ensemble, and is confirmed through the free-space absorption spectroscopy of the MOT. The free space gain required for the lasing action is significantly smaller in our system as compared to the cases where there is no collective strong coupling.Cold atoms coupled to an optical cavity provide an ideal platform for creating lasers without conventional population inversion. Such lasers can generate very high spectral purity, and the output can be precisely controlled by varying the atom-drive or atom-cavity parameters. In this letter, we report experimental observation of gain, amplification, and self-lasing within a continuously operated 85 Rb magneto-optic trap (MOT), in the collective strong coupling regime of the atom-cavity system. The presence of MOT cooling lasers significantly alters the transmission properties of the cavity, and gain is observed in one of the vacuum Rabi peaks. The system makes a transition from an amplifying medium to a self-sustained laser as the MOT parameters are tuned. The underlying lasing mechanism is shown to be Mollow gain in the driven atomic ensemble, and is confirmed through the free-space absorption spectroscopy of the MOT. The free space gain required for the lasing action is significantly smaller in our system as compared to the cases where there is no collective strong coupling.

Optics ContinuumMar 25, 20252 citations

We report on the observation of a new magic frequency within the hyperfine structure of the D2 line of

{}^{87}

Rb atoms at which the scattering of light into a high-finesse cavity is suppressed by an interplay between quantum interference and the strong collective coupling of atoms to the cavity. Scattering from a cloud of laser-driven cold atoms into the cavity was measured in a polarization sensitive way. We have found that both the Rayleigh and Raman scattering processes into the near-resonant cavity modes are extinguished at 185 MHz below the F=2

\leftrightarrow

F'=3 transition frequency. This coincidence together with the shape of the observed spectral dip imply that the effect relies on a quantum interference in the polariton excitations of the strongly coupled combined atom-photon system. We have also demonstrated the existence of a magic frequency around -506 MHz, where only the Raman scattering is suppressed due to a quantum interference effect at the single-atom level.