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Optical and Quantum Electronics

Space-time cloaking through a chiral atomic medium

Hussain Ahmad, Amin Ur Rahman, Umer Wahid, Bakht Amin Bacha, Shahid Mahmood Ramay

Published Aug 1, 2021• 5 citations
Publisher

Abstract

Abstract The birefringence characteristics of reflection and transmission of light pulse are explored in chiral medium driving by two probe electric and magnetic fields, while four control fields. The proposed medium show significant birefringence behaviors in reflection/transmission and Goos-Hänchen (GH) shifted beams. The birefringent GH-reflected and GH-transmitted pulses show significant contribution in the space time gap creation for secure communication and invisibility. A space-time gap has been observed in the reflection, transmission and corresponding GH-shifted reflection and transmission birefringent beams. The theoretical results may be useful for noise free secure communication in invisible radar technology.

DOI
10.1007/s11082-021-03101-9

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Abstract We theoretically investigate birefringence of lateral Goos-Hänchen (GH) shift in a tunnelling chiral atomic medium. The Milnor polynomial of controlled fields and tunnelling modulate the light-mater interactions. We analyze the GH shift for right- and left-circularly polarized (RCP and LCP) beams for varying incident angles. We found a lossless condition R (+) + T (+) = 1 for RCP beams at the incident angle θ i = π /3, while LCP beams shows loss R (−) + T (−) + A (−) = 1 and A (−) = 0.2. The lateral shift in reflection of RCP beam varies in range of 0 λ ≤ S r ( + ) ≤ 60 λ and transmission of RCP beam varies in the range of 0 λ ≤ S t ( + ) ≤ 100 λ at θ i = π /3, while the shift in LCP beam decreases 0 λ ≤ S r ( − ) ≤ 40 λ and transmission increases 0 λ ≤ S t ( − ) ≤ 150 λ for the same parameters. Further, for incident angle θ i = π /4, we found an increase in lateral shifts S r , t ( − ) ≤ 150 λ for RCP and 0 λ ≤ S r , t (
Abstract This paper reports theoretical investigation of birefringence in a chiral medium for the creation of temporal cloaking. The chiral medium splits the input probe beam into left/right circular polarized beams. These left/right circular polarized beams are then controlled and modified within the chiral medium. The left circular polarized beam delays by 24 ns whereas the right circular polarized beam advances by −23 ns at a control field of rabbi frequency 6 γ . This opens a 47 ns time gap for temporal cloaking to hide information without noise corruption and energy loss. The results have potential applications in communication devices for secure propagation of light pulse.