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arXiv · 2212.01195

Exotic light transition between superluminal and subliminal group velocity in a $\mathcal{PT}$ coupled slab waveguide

B. M. Villegas-Martínez·H. M. Moya-Cessa·F. Soto-Eguibar
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Abstract

We propose a rigorous full-wave modal analysis based on the eigenmodes approach (\textquotedblleft supermodes\textquotedblright), that allows the calculation of the transverse electric ($TE$) and transverse magnetic ($TM$) stationary propagation eigenmodes in a coupled $\mathcal{PT}$-symmetric slab waveguide. Our findings show that the group velocity, for the fundamental $TE_{0}$ supermode, passes from superluminal to subluminal speed over both sides of a critical point (CP), located near to the exceptional point (EP). We also demonstrate that the first higher-order supermode, $TE_{1}$, exhibits a slow light phenomenon around the EP.

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B. M. Villegas-Martínez, H. M. Moya-Cessa, F. Soto-Eguibar. 2022-12-02. Exotic light transition between superluminal and subliminal group velocity in a $\mathcal{PT}$ coupled slab waveguide. https://doi.org/10.1016/j.photonics.2023.101128

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