Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 32: Focussed Session: Frontiers in Exploring and Applying Plasmonic Systems I
(Joint Session of CPP, DS, HL, MM, and O, organized by DS)

HL 32.4: Topical Talk

Tuesday, March 21, 2017, 11:15–11:45, CHE 89

Switchable infrared nanophotonic elements enabled by phase-change materials — •Thomas Taubner — Institute of Physics (IA), RWTH Aachen University

The strong confinement and enhancement of light when coupled to surface waves or nanoparticles is key for various applications in nanophotonics such as sensing, imaging or the manipulation of light fields. In the mid-infrared spectral range, metallic nanoantennas and materials supporting surface phonon polaritons (SPhPs) can be used as building blocks of such devices. Often, their optical functionality is only obtained at a fixed wavelength, determined by the geometric design and the material properties.

By using phase-change materials (PCMs) as tunable environment for nanophotonic resonators, their resonance frequency can be altered in a non-volatile, reversible way. PCMs offer a huge change in refractive index due to a phase transition from their amorphous to crystalline state, which can be thermally, optically or electrically triggered. We present results on thermal and optical switching, as well as addressing of individual IR resonances of both systems, metallic nanoantennas and resonators for SPhPs. SPhPs on polar dielectrics exhibit lower losses and larger Q-values compared to metallic nanoantennas, and their confinement can be even increased by adding ultrathin, switchable PCM layers. We show the all-optical, non-volatile, and reversible switching of the SPhPs by controlling the structural phase of the PCM [1], opening the door for re-configurable metasurfaces.

[1] P. Li et al., Nat. Mat. 15, 870 (2016).