Photonic spin Hall effect in hyperbolic metamaterials for polarization-controlled routing of subwavelength modes

Abstract

The routing of light in a deep subwavelength regime enables a variety of important applications in photonics, quantum information technologies, imaging and biosensing. Here we describe and experimentally demonstrate the selective excitation of spatially confined, subwavelength electromagnetic modes in anisotropic metamaterials with hyperbolic dispersion. A localized, circularly polarized emitter placed at the boundary of a hyperbolic metamaterial is shown to excite extraordinary waves propagating in a prescribed direction controlled by the polarization handedness. Thus, a metamaterial slab acts as an extremely broadband, nearly ideal polarization beam splitter for circularly polarized light. We perform a proof of concept experiment with a uniaxial hyperbolic metamaterial at radio-frequencies revealing the directional routing effect and strong subwavelength l/300 confinement. The proposed concept of metamaterial-based subwavelength interconnection and polarizationcontrolled signal routing is based on the photonic spin Hall effect and may serve as an ultimate platform for either conventional or quantum electromagnetic signal processing.

Spin–orbit coupling in surface plasmon scattering by nanostructures

“…As a starting point, Fig. 2a shows the direct PSHE 7,13 , where the scattering of circularly polarized light by a spherical metal nanoparticle leads to the directional excitation of SPP waves dependent on the wavevector and spin of incoming photons. SPPs are excited on a smooth metal film on the left or the right from the nanoparticle corresponding to the right-handed or left-handed polarization state of the illuminating light, respectively (Fig.…”

High aspect ratio titanium nitride trench structures as plasmonic biosensor

“…The trench structures have dimensions of 2×2 cm 2 . These structural parameters can be controlled and optimized for various applications by the mask for deep-UV lithography and the subsequent processes, providing more flexibility in design of the trench structures and related metamaterial platforms with extreme anisotropy for steering of optical signals on the surface of metamaterials for longer wavelengths in the near-infrared and mid-infrared regions [37, [52][53][54][55][56][57][58][59][60]. The deposited TiN films become plasmonic in the visible wavelength of around 490 nm (2.53 eV) for annealed ones at 900 • C as opposed to 665 nm (1.86 eV) of as-deposited films.…”

Plasmonic and Dielectric Metasurfaces: Design, Fabrication and Applications

“…Nanoimprint lithography is a more promising technique for combining many advantages of the former, such as high-resolution, large-scaled production and low processing cost [73]. The unique properties and the development of fabrication techniques have allowed metasurfaces to be applied in various fields, such as flat optics [33][34][35], nonlinear effects [101][102][103][104][105][106][107], photonic Hall effects [108][109][110], electromagnetically-induced transparency [111], cloaking [112][113][114][115][116][117], etc., as shown in Figure 2. For instance, the applications of metasurfaces in the field of flat optics mainly include anomalous reflection/refraction [34,81,82], wave plates [79,80], flats lens/axicons [83][84][85], mirrors [88], hologram [90][91][92][93][94][95], filters [96], optical vortex generation [34,85,98,99], polarization beam splitter [100], etc.…”