Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 55: Photonic crystals

HL 55.1: Talk

Friday, March 31, 2006, 11:30–11:45, BEY 154

Probing Photonic Crystals with Single CdSe/ZnS Quantum Dots — •Frank Cichos¹, Michael Barth², Roman Schuster³, and Achim Gruber¹ — ¹Photonics and Optical Materials, Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz — ²Nano-Optics Group, Institute of Physics, Humoldt University Berlin, Hausvogteiplatz 5-7, 10117 Berlin — ³Leibniz Institute for Solid State and Materials Research Dresden, PF 27 01 16, 01171 Dresden

Within this presentation we demonstrate for the first time the application of single quantum dots to measure local optical properties of a 3D photonic crystal (PC). We have doped artificial polystyrene opals with a low concentration of core-shell CdSe/ZnS quantum dots, which emit in the region of the photonic stop band. With the help of fluorescence microscopy we demonstrate, that individual quantum dots can be imaged with high quality even though they are more than 30 lattice planes inside the PCs. Based on a comparison of defocused fluorescence images with numerical calculations, we show that the angular radiation characteristics of single quantum dots is modified by the photonic stop band. The variation of the photonic stop band position with the orientation of the crystal prevents light emission from the quantum dot in certain directions. This is to our knowledge the first measurement of photonic stop band effects based on a single emitter inside a PC and opens up a new class of experiments studying the local optical properties of 3D PCs. The results of this study can be advantageously used to manipulate the angular radiation characteristics of single photon sources.