Regensburg 2016 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 23: Plasmonics and Nanooptics: Light-Matter Interaction, Spectroscopy

O 23.17: Poster

Montag, 7. März 2016, 18:15–20:30, Poster E

Fine-tuning and individual addressing of mid-IR nanoantenna resonances by reversible optical switching of Ge3Sb2Te6 thin-films — •Ann-Katrin U. Michel, Dmitry N. Chigrin, Thomas Kalix, Angela De Rose, Matthias Wuttig, and Thomas Taubner — RWTH Aachen University, 1. Institute of Physics A, Otto-Blumenthal-Straße, 52074 Aachen

Metallic nanostructures with well-defined resonances are a key building block for nanoscale photonic "meta-devices". The post-fabrication control over the nanostructures resonances is fundamental for enabling reconfigurable devices based on metamaterials, which allow for all-optical switchable nanophotonic imaging and sensors [1].

We present the tuning of the spectral position of the nanostructure resonance frequency by locally addressing phase-change material (PCM) thin-films with single nanosecond laser pulses. PCMs offer a huge contrast in the refractive index n due to a phase transition from their amorphous to their crystalline state. By optically induced local phase transitions, the effective n of the PCM medium, which affects the resonant structures resonance, can be tuned over a broad range.

The variation of the PCM area switched by a laser pulse allows us to reversibly alter the nanostructure resonance frequency of a 600 nm long rod-shaped antenna stepwise in the mid-infrared spectral range [2]. The local addressing enables a multi-step tuning of single nanostructures pointing towards actively controllable metasurfaces.

[1] Zheludev, N. I. et al. Nat. Mater. 11 (2012).

[2] Michel, A. U. et al. in preparation