Dresden 2011 – wissenschaftliches Programm
O 18.1: Vortrag
Montag, 14. März 2011, 17:15–17:30, PHY C213
Lithographically defined plasmonic waveguides on semiconductors for on-chip quantum optics applications — •Gregor Bracher, Konrad Schraml, Benedikt Mayer, Birgit Wiedemann, Simon Frédéric, Jonathan J. Finley, and Michael Kaniber — Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, D-85748 Garching, Germany
We present optical investigations on lithographically defined plasmonic waveguides (WG). The metallic WGs are fabricated on GaAs substrates by electron beam lithography and subsequent metallisation. Structural properties are probed by atomic force microscopy and scanning electron microscopy revealing a surface roughness below 3 nm. For the optical characterisation we use a two axis confocal micro-photoluminescence setup that enables us to excite and detect plasmons perpendicular and parallel to the sample surface. First measurements show that Au WGs with a thickness of 100 nm and width of 4 µ m exhibit a propagation length of 15 µ m at λ=820 nm. We clearly observe strong localisation of the excitation at the wire end and the expected polarisation dependence along the WG axis. Using the same technique we prove that plasmons can be excited in lithographically defined Au nanowires with a cross section down to 100x100 nm2. The deterministic control of the position and shape of the plasmonic nanostructures by means of electron beam lithography combined with near surface self-assembled InGaAs/GaAs quantum dots promises efficient on-chip generation and guiding of single plasmons for future applications in nanoscale quantum optics.