Hybrid surface phononic waveguide using hyperbolic boron nitride

Opt Express. 2016 Jul 25;24(15):17183-92. doi: 10.1364/OE.24.017183.

Abstract

Sub-diffraction limited waveguides have been studied as a means to manipulate light into nanoscale regions. Hybrid waveguides are popular candidates in optical regimes for subwavelength confinement and long range propagation. However, advances in the mid-IR are lacking due to high propagation losses and limited confinement. Here we present the first analysis of hybrid phononic waveguide using a hyperbolic material h-BN to generate surface phonon polaritons. The strong coupling between the photonic cylinder and phononic surface enhances the confined field up to 10-3 λo 2o is free-space wavelength) and enables propagation distances up to 100 λo. Our work is fully compatible with integrated polaritonic devices in the mid-IR and provides a systematic approach to design hybrid phononic waveguides.