Absorption resonance and large negative delay in Rb vapor with buffer gas

Abstract

We observe a narrow, isolated, two-photon absorption resonance in Rb for large one-photon detuning in the presence of a buffer gas. In the absence of buffer gas, a standard Lambda configuration of two laser frequencies gives rise to electromagnetically induced transparency (EIT) for all values of one-photon detuning throughout the inhomogeneously (Doppler) broadened line. However, when a buffer gas is added and the one-photon detuning is comparable to or greater than the Doppler width, an absorption resonance appears instead of the usual EIT resonance. We also observe large negative group delay (~ -300 us for a Gaussian pulse propagating through the media with respect to a reference pulse not affected by the media), corresponding to a superluminal group velocity v_g= -c/(3.6x10^6)=-84 m/s.

4 pages, 5 figures

References in corpus (3)

• Storage of light in atomic vapor
• Narrowing of EIT resonance in a Doppler Broadened Medium
• Theory of dark resonances for alkali vapors in a buffer-gas cell

Cited by in corpus (16)

• Electromagnetically induced transparency controlled by a microwave field
• Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas
• Electromagnetically induced absorption in a non-degenerate three-level ladder system
• Buffer-gas induced absorption resonances in Rb vapor
• Optimal superluminal systems
• Theory of slow-light solitons
• Two-pulse interference and superluminality
• Weak-value amplification of the fast-light effect in rubidium vapor
• Vapor pressure dependence of spectral width of EIT in Lambda-level cesium molecular system
• Anomalous dispersion and negative group velocity in a coherence-free cold atomic medium
• Suppression of the four-wave mixing amplification via Raman absorption
• Manipulation of optical solitons in Bose-Einstein condensates
• Intensity correlations in resonance nonlinear magneto-optical rotation
• A relation between electromagnetically induced absorption resonances and nonlinear magneto-optics in Lambda-systems
• Slow Light Propagation in a Linear-Response Three-Level Atomic Vapor
• Propagation of a squeezed optical field in a medium with superluminal group velocity