Influence of Frequency-Sweep on Discrete and Continuous Phase Distributions Generated in Alkali-Metal Vapours

Abstract

This paper describes a comparable study on the influence of frequency-sweep on the discrete and continuous phase distributions associated with pulse excitations for a double-lambda atomic system in alkali-metal vapours with a hyperfine structure. The excitation dynamics provided a different scheme of sigmoidal types, and the optical pulses were assumed to be Gaussians. We focused on the set-up of electromagnetically induced transparency (EIT). The phases of optical fields show similarities to discrete square wave distributions influenced by ramping. The results showed significant control of discrete phase distributions and temporal ramping by the implementation of sigmoidal membership functions. The relevant equations are the reduced Maxwell equations for the radiation fields, and the density matrix equation in the Liouville space governs the time evolution.

Keywords

• electromagnetically-induced transparency
• continuous frequency-sweep
• stepped frequency-sweep
• sigmoidal membership functions implementation
• alkali-metal vapours
• D₁ line