Enhanced index of refraction in four-wave mixing media

Abstract

Refractive index enhancement accompanied by vanishing absorption in a four-level atomic system interacting with two control and two probe fields in a regime of four-wave mixing (FWM) has been predicted and studied in the present work. We analyzed the maximal index enhancement in the four-level FWM system and gave index estimates for a real atomic gas of ${}^{40}$K, taking into account its multilevel structure and collisional and Doppler broadenings at large atomic densities. We also discussed how vanishing absorption with no nearby amplification can be realized in a two species system, consisting of a four-level FWM and a two-level system, where the latter provides additional absorption for one of the probe fields. We numerically estimated the index change in a system composed of ${}^{40}$K and ${}^{39}$K gases.

References in corpus (2)

• PT-symmetry with a system of three-level atoms
• Refractive Index Enhancement with Vanishing Absorption in an Atomic Vapor

Cited by in corpus (2)

• Tunable fast and slow light in a hybrid optomechanical system
• Controllable linear $\pi$-phase modulation in a thermal atom vapor without diffraction or absorption