Light Pulse Slowing Down up to 0.025 cm/s by Photorefractive Two-Wave Coupling

Abstract

It is shown experimentally and theoretically that photorefractive wave coupling can be used for dramatic (< or approximately 0.025 cm/s) deceleration of light pulses whose width is larger than (or comparable with) the nonlinear response time. This classical nonlinear scheme exhibits similarities with the technique based on the quantum effect of electromagnetically induced transparency. The main distinctive feature of our scheme is amplification of the delayed output pulse. Advantages of the novel technique and its prospects for manipulation with light photons are discussed.

Fiber-Based Slow-Light Technologies

“…Note that (3) is only valid for narrowband pulses, though it serves as an upper bound to the delay if higher order distortion becomes important. Group indexes as large as have been observed experimentally in a Bose-Einstein condensate (BEC) [6] and as large as in a room-temperature photoreactive crystal [7]. In fibers, group indexes on the order of have been achieved using erbiumdoped fiber amplifiers [8].…”

Slow and fast light: basic concepts and recent advancements based on nonlinear wave‐mixing processes

“…Another approach working in room-temperature solids resorts to nonlinear wave mixing in photorefractive crystals. By operating close to Bragg resonance, the group velocities of 5 cm/s and 0.16 cm/s were obtained with this method in [10,11] and [12], respectively. Other recent techniques employed nonlinear effects in optical fibers, such as amplification by stimulated Brillouin scattering [13][14][15][16], for which a continuous pump and a probe pulse interact through the creation of an acoustic wave, providing both slow and fast light effects depending on the relative detuning between pump and probe.…”

“…The wave equation for the Fourier transform of the electric field is r 2î + 3 2 2 (1 +1(3)) +î = 0Y (10) and the refractive index n = p 1 +1 (3) (11) where is the Cauchy principal value. The above equations, Eqs.…”

Observation of Superluminal in Doppler Broadened Two-Level Atomic Systems in Magnetic Field

“…Slow light propagation can be achieved by using the techniques of electromagnetically induced transparency (EIT) [1][2][3][4], coherent population oscillations (CPO) [5][6], coherent hole burning (CHB) [7][8], two-wave mixing [9], stimulated Brillouin scattering (SBS) [10], stimulated Raman scattering (SRS) [11], and so on. In superluminal area Brillouin showed theoretically that inside an absorption line the dispersion is anomalous, which resulted in a group velocity faster than c in 1960 [12], and negative group velocity of -c/(300 + 30) in Cs atom vapor was found in 2000 [13].…”