Slow light by Bloch surface wave tunneling

Abstract

We demonstrate a slow light configuration that makes use of Bloch Surface Waves as an intermediate excitation in a double-prism tunneling configuration. This method is simple compared to the more usual technique for slowing light using the phenomenon of electromagnetically induced transparency in atomic gases or doped ionic crystals operated at temperatures below 4 K. Using a semi-numerical approach, we show that a 1D photonic crystal, a multilayer structure composed of alternating layers of TiO(2) and SiO(2), can be used to slow down light by a factor of up to 400. The results also show that better control of the speed of light can be achieved by changing the number of bilayers and the air-gap thickness appropriately.

Electromagnetic field enhancement in Bloch surface waves

“…In the last decade, we witnessed a growing interest in Bloch surface waves (BSWs) [15][16][17][18][19][20][21][22], which are electromagnetic modes that propagate at the interface between a truncated periodic multilayer and a dielectric external medium. Light confinement in BSWs occurs near the multilayer surface and is caused by TIR from the homogeneous layer and by the presence of a photonic band gap (PBG) from the multilayer.…”

Leaky Bloch-like surface waves in the radiation-continuum for sensitivity enhanced biosensors via azimuthal interrogation

“…Following the prediction 1 and experimental observation 2 of BSWs in photonic crystals, these modes have been studied, both theoretically and experimentally, in various configurations 3 – 6 . The resulting strong field/energy localization at the surface layer and the evanescently extending field in the homogeneous medium are of interest in applications such as label-free biosensing based on enhanced diffraction 7 – 9 , surface-enhanced Raman spectroscopy 10 , 11 , spectral and angular resonance shift 12 – 16 , fluorescence-based detection 17 – 20 , slow-light enhanced nonlinear effects 21 , 22 , integrated optical circuits 23 , and optical slow-light devices and sensors 24 , 25 . BSWs are evanescent in nature; they are perfectly bound non-radiative states that lie below the light line of the homogeneous layer material.…”

In-plane 2D focusing of surface waves by ultrathin refractive structures

“…In this respect, BSWs can be seen as a photonic counterpart of surface plasmon polaritons (SPPs). There are several advantages in using BSW for sensing applications, such as the very low absorption losses exhibited by typical dielectric materials (e.g., silicon alloys [9], titania [10], tantalia [11], and also polymers [12]), a high degree of spectral and polarization tunability of surface resonances [13], a generally high Q-factor, and a corresponding strong field enhancement produced at the multilayer surface [14,15], giving an effective advantage in sensing applications when compared to typical ridge waveguide sensors, whose sensitivity is limited by the burial of the guided mode inside the high index layer [16].…”