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

Chinese Optics Letters

Phase-controlled gain, phase shift, and group velocity using a room-temperature active-Raman-gain medium

Chao Hang, Guoxiang Huang

Published Jan 1, 2009• 0 citations
Publisher

Abstract

A four-level tripod active-Raman-gain scheme is analyzed for obtaining phase-controlled gain, phase shift, and group velocity at room temperature.The scheme can be used to eliminate significant probe field attenuation or distortion which is unavoidable in the scheme based on electromagnetically induced transparency.It is shown that the intensity gain, phase shift, and group velocity of a probe field can be simultaneously manipulated by changing the relative phase of two pump fields.The scheme is also different from that proposed recently by Deng et al.where a probe-field gain always exists.New features of the scheme presented here raise the possibility of designing rapidly responding optical switches and gates for optical information processing.

DOI
10.3788/col20090707.0549

Related papers

Gain-Assisted Large and Rapidly Responding Kerr Effect using a Room-Temperature Active Raman Gain Medium

L. Deng, M. G. Payne

A four-level N scheme with a two-mode active Raman gain core is investigated for large and rapidly responding Kerr effect enhancement at room temperature. The new scheme is fundamentally different from the electromagnetically induced transparency (EIT-)based ultraslow-wave Kerr effect enhancement scheme. It eliminates the requirement of group velocity matching and multispecies medium. It also eliminates significant probe field attenuation or distortion associated with weakly driven EIT-based schemes. We show that a probe field can acquire a large, frequency tunable, gain-assisted nonlinear phase shift and yet travel with gain-assisted superluminal propagation velocity. This raises the possibility of rapidly responding, frequency tunable nonlinear phase switching and phase gates for information science.

Physical Review Letters•Jun 22, 2007•68 citations

Highly entangled photons and rapidly responding polarization qubit phase gates in a room-temperature active Raman gain medium

Chao Hang, Guoxiang Huang

We present a scheme for obtaining entangled photons and quantum phase gates in a room-temperature four-state tripod-type atomic system with two-mode active Raman gain (ARG). We analyze the linear and nonlinear optical responses of this ARG system and show that the scheme is fundamentally different from those based on electromagnetically induced transparency and hence can avoid significant probe-field absorption as well as a temperature-related Doppler effect. We demonstrate that highly entangled photon pairs can be produced and rapidly responding polarization qubit phase gates can be constructed based on the unique features of the enhanced cross-phase-modulation and superluminal probe-field propagation of the system.

arXiv:1112.0764•Physical Review A•Nov 16, 2010•9 citations

Weak-light superluminal vector solitons in a room-temperature four-level active-Raman-gain medium

Chao Hang, Guoxiang Huang

We propose a scheme to generate vector optical solitons in a four-level active-Raman-gain medium. We show that this scheme, which is fundamentally different from that using optical fibers and that via electromagnetically induced transparency, is capable of achieving robust vector optical solitons with superluminal propagating velocity. We demonstrate that such vector optical solitons can be generated at room temperature and with very low light intensity. We investigate also the interaction between two superluminal vector optical solitons and point out that their elastic and inelastic colliding properties can be used to design rapidly responding optical soliton switching and logic gates.

Journal of the Optical Society of America B•Feb 6, 2009•9 citations

Significant propagation reduction of an optical pulse in an active Raman gain scheme

Kaijun Jiang, L. Deng, M. G. Payne

We investigate an active Raman gain scheme for significant group velocity reduction. This scheme, which is fundamentally different from the electromagnetically induced transparency scheme, is capable of achieving ultraslow and distortion-free propagation of a pulsed probe field. The group velocity behavior is drastically different from the conventional electromagnetically induced transparency scheme, and the new scheme can be used to accurately determine the decoherence rate of a long-lived state. In addition, the Raman gain scheme has the advantage of being broadly tunable, an important feature that may have potential applications.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 8, 2007•0 citations

Ultraslow propagation of an optical pulse in a three-state active Raman gain medium

Kaijun Jiang, L. Deng, M. G. Payne

We investigate an active Raman gain scheme for significant group velocity reduction. We show that this scheme, which is fundamentally different from the electromagnetically induced transparency scheme, is capable of achieving ultraslow and distortion-free propagation of a pulsed probe field. We demonstrate the group velocity behavior that is drastically different from the conventional electromagnetically induced transparency scheme, and we show that the new scheme can be used to accurately determine the decoherence rate of a long-lived state. In addition, the Raman gain scheme has the advantage of being broadly tunable, an important feature that may have potential applications.

Physical Review A•Oct 9, 2006•41 citations

Double Double Electromagnetically Induced Transparency

Hessa M. M. Alotaibi

This study demonstrates that tripod atom-field electronic structure can yield rich electromagnetically induced transparency phenomena, even at room temperature. In particular, we introduce double double electromagnetically induced transparency (DDEIT), wherein signal and probe fields each have two transparency windows. Their group velocities can be matched in either the first or second pair of transparency windows. Moreover, signal and probe fields can each experience coherent Raman gain in the second transparency window. Our investigation has demonstrated that the self-phase modulation (SPM) and cross-phase modulation (XPM) vanish at the center of two transparency windows for resonant coupling field. However, the values of the XPM and SPM in the region of the second EIT window are improved by a factor of $1000$ compared to their values in the region of the first EIT window under the same conditions, and have non-zero values at the center of the second EIT window for nonresonant coupling field. Additionally, we derive an analytical solution for the wave equation describing the propagation of the probe field whose amplitude-envelope function is described by the fundamental mode Laguerre-Gaussian function. Our solution exhibits that the group velocity of the probe field reduces as the field propagates through the medium. The group velocity reduction is a consequence of spatially-varying susceptibility. The variation of the susceptibility is established by employing signal field whose amplitude-envelope functions is also described by the fundamental mode Laguerre-Gaussian function. For Doppler-broadened media, we devise a scheme to control and reduce the probe-field group velocity at the center of the second transparency window. We derive numerical and approximate analytical solutions for the width of electromagnetically induced transparency (EIT) windows and for the group velocities of the probe field at the two distinct transparency windows, and we show that the group velocities of the probe field can be lowered by judiciously choosing the physical parameters of the system. Our modeling enables us to identify three signal-field strength regimes quantified by the Rabi frequency, for slowing the probe field. Our scheme exploits the fact that the second transparency window is sensitive to a temperature-controlled signal-field nonlinearity, whereas the first transparency window is insensitive to this nonlinearity.

•Jan 1, 2015•0 citations
A four-level tripod active-Raman-gain scheme is analyzed for obtaining phase-controlled gain, phase shift, and group velocity at room temperature.The scheme can be used to eliminate significant probe field attenuation or distortion which is unavoidable in the scheme based on electromagnetically induced transparency.It is shown that the intensity gain, phase shift, and group velocity of a probe field can be simultaneously manipulated by changing the relative phase of two pump fields.The scheme is also different from that proposed recently by Deng et al.where a probe-field gain always exists.New features of the scheme presented here raise the possibility of designing rapidly responding optical switches and gates for optical information processing.
A four-level N scheme with a two-mode active Raman gain core is investigated for large and rapidly responding Kerr effect enhancement at room temperature. The new scheme is fundamentally different from the electromagnetically induced transparency (EIT-)based ultraslow-wave Kerr effect enhancement scheme. It eliminates the requirement of group velocity matching and multispecies medium. It also eliminates significant probe field attenuation or distortion associated with weakly driven EIT-based schemes. We show that a probe field can acquire a large, frequency tunable, gain-assisted nonlinear phase shift and yet travel with gain-assisted superluminal propagation velocity. This raises the possibility of rapidly responding, frequency tunable nonlinear phase switching and phase gates for information science.
We present a scheme for obtaining entangled photons and quantum phase gates in a room-temperature four-state tripod-type atomic system with two-mode active Raman gain (ARG). We analyze the linear and nonlinear optical responses of this ARG system and show that the scheme is fundamentally different from those based on electromagnetically induced transparency and hence can avoid significant probe-field absorption as well as a temperature-related Doppler effect. We demonstrate that highly entangled photon pairs can be produced and rapidly responding polarization qubit phase gates can be constructed based on the unique features of the enhanced cross-phase-modulation and superluminal probe-field propagation of the system.
We propose a scheme to generate vector optical solitons in a four-level active-Raman-gain medium. We show that this scheme, which is fundamentally different from that using optical fibers and that via electromagnetically induced transparency, is capable of achieving robust vector optical solitons with superluminal propagating velocity. We demonstrate that such vector optical solitons can be generated at room temperature and with very low light intensity. We investigate also the interaction between two superluminal vector optical solitons and point out that their elastic and inelastic colliding properties can be used to design rapidly responding optical soliton switching and logic gates.
We investigate an active Raman gain scheme for significant group velocity reduction. This scheme, which is fundamentally different from the electromagnetically induced transparency scheme, is capable of achieving ultraslow and distortion-free propagation of a pulsed probe field. The group velocity behavior is drastically different from the conventional electromagnetically induced transparency scheme, and the new scheme can be used to accurately determine the decoherence rate of a long-lived state. In addition, the Raman gain scheme has the advantage of being broadly tunable, an important feature that may have potential applications.
We investigate an active Raman gain scheme for significant group velocity reduction. We show that this scheme, which is fundamentally different from the electromagnetically induced transparency scheme, is capable of achieving ultraslow and distortion-free propagation of a pulsed probe field. We demonstrate the group velocity behavior that is drastically different from the conventional electromagnetically induced transparency scheme, and we show that the new scheme can be used to accurately determine the decoherence rate of a long-lived state. In addition, the Raman gain scheme has the advantage of being broadly tunable, an important feature that may have potential applications.
This study demonstrates that tripod atom-field electronic structure can yield rich electromagnetically induced transparency phenomena, even at room temperature. In particular, we introduce double double electromagnetically induced transparency (DDEIT), wherein signal and probe fields each have two transparency windows. Their group velocities can be matched in either the first or second pair of transparency windows. Moreover, signal and probe fields can each experience coherent Raman gain in the second transparency window. Our investigation has demonstrated that the self-phase modulation (SPM) and cross-phase modulation (XPM) vanish at the center of two transparency windows for resonant coupling field. However, the values of the XPM and SPM in the region of the second EIT window are improved by a factor of 100010001000 compared to their values in the region of the first EIT window under the same conditions, and have non-zero values at the center of the second EIT window for nonresonant coupling field. Additionally, we derive an analytical solution for the wave equation describing the propagation of the probe field whose amplitude-envelope function is described by the fundamental mode Laguerre-Gaussian function. Our solution exhibits that the group velocity of the probe field reduces as the field propagates through the medium. The group velocity reduction is a consequence of spatially-varying susceptibility. The variation of the susceptibility is established by employing signal field whose amplitude-envelope functions is also described by the fundamental mode Laguerre-Gaussian function. For Doppler-broadened media, we devise a scheme to control and reduce the probe-field group velocity at the center of the second transparency window. We derive numerical and approximate analytical solutions for the width of electromagnetically induced transparency (EIT) windows and for the group velocities of the probe field at the two distinct transparency windows, and we show that the group velocities of the probe field can be lowered by judiciously choosing the physical parameters of the system. Our modeling enables us to identify three signal-field strength regimes quantified by the Rabi frequency, for slowing the probe field. Our scheme exploits the fact that the second transparency window is sensitive to a temperature-controlled signal-field nonlinearity, whereas the first transparency window is insensitive to this nonlinearity.