Fabrication of three-dimensional photonic crystals in quantum-dot-based materials

Controlling spontaneous emission (SE) is of fundamental importance to a diverse range of photonic applications including but not limited to quantum optics, low power displays, solar energy harvesting and optical communications. Characterized by photonic bandgap (PBG) property, three-dimensional (3D) photonic crystals (PCs) have emerged as a promising synthetic material, which can manipulate photons in much the same way as a semiconductor does to electrons. Emission tunable nanocrystal quantum dots (QDs) are ideal point sources to be embedded into 3D PCs towards active devices. The challenge however lies in the combination of QDs with 3D PCs without degradation of their emission properties. Polymer materials stand out for this purpose due to their flexibility of incorporating active materials. Combining the versatile multi-photon 3D micro-fabrication techniques, active 3D PCs have been fabricated in polymer-QD composites with demonstrated control of SE from QDs. With this milestone novel miniaturized photonic devices can thus be envisaged. Sketch of a three-dimensional woodpile photonic crystal fabricated within a QD-doped polymer nanocomposite material. Overall dimensions of the photonic crystal are on the order of millimeters, individual structural elements are on the order of micrometers while the quantum dots are nanometer-sized. [GRAPHICS] (C) 2010 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim