Controllable linear $\pi$-phase modulation in a thermal atom vapor without diffraction or absorption

Abstract

A scheme is proposed to achieve substantial controllable phase modulation for a probe field propagating through a thermal atomic vapor in double-$\Lambda$ configuration. The phase modulation is based on the linear susceptibility of the probe field, paraxial diffraction is eliminated by exploiting the thermal motion of atoms, and residual absorption is compensated via an incoherent pump field. As a result, a strong controllable uniform phase modulation without paraxial diffraction is achieved essentially independent of the spatial profile or the intensity of the probe field. This phase shift can be controlled via the intensities of the control or the incoherent pump fields. A possible proof-of-principle experiment in alkali atoms is discussed.

10 pages, 7 figures

References in corpus (5)

• Tunable negative refraction without absorption via electromagnetically induced chirality
• Refractive Index Enhancement with Vanishing Absorption in an Atomic Vapor
• Theory of Thermal Motion in Electromagnetically Induced Transparency: Diffusion, Doppler, Dicke and Ramsey
• Elimination of the Diffraction of Arbitrary Images Imprinted on Slow Light
• Theory of Dicke narrowing in coherent population trapping