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

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 $\mathcal{P}\mathcal{T}$-symmetric slab waveguide. Our findings show that the group velocity, for the fundamental $T{E}_0$ 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, $T{E}_1$, exhibits a slow light phenomenon around the EP.

22 pages

References in corpus (6)

• Electromagnetically Induced Transparency and Slow Light with Optomechanics
• The physics of exceptional points
• Visualization of Branch Points in PT-Symmetric Waveguides
• Light stops at exceptional points
• Sub- and super-luminal light propagation using a Rydberg state
• Revisit the Poynting vector in PT-symmetric coupled waveguides