Richard Schaller

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There is much current interest in the optical properties of semiconductor nanowires, because the cylindrical geometry and strong two-dimensional confinement of electrons, holes and photons make them particularly attractive as potential building blocks for nanoscale electronics and optoelectronic devices, including lasersand nonlinear optical frequency(More)
The nonlinear optical response of semiconductor nanowires has potential application for frequency conversion in nanoscale optical circuitry. Here, second-and third-harmonic generation (SHG, THG) are imaged on single zinc oxide (ZnO) nanowires using near-field scanning optical microscopy (NSOM). The absolute magnitudes of the two independent (2) elements of(More)
We demonstrate focusing coherent light on a nanoparticle through turbid media based on digital optical phase conjugation of second harmonic generation (SHG) field from the nanoparticle. A SHG active nanoparticle inside a turbid medium was excited at the fundamental frequency and emitted SHG field as a point source. The SHG emission was scattered by the(More)
We present a theoretical analysis of lasing action in photonic crystal surface-emitting lasers (PCSELs). The semiclassical laser equations for such structures are simulated with three different theoretical techniques: exact finite-difference time-domain calculations, an steady-state ab-initio laser theory and a semi-analytical coupled-mode formalism. Our(More)
Distributed events are collections of single events taking place within a small geographical area at approximately the same time, normally related to one given topic e.g. music, film, arts etc. There are usually a large number of events on offer and the times in which they can be visited are heavily constrained. Therefore the information seeking task of(More)
Ultraviolet lasing from single zinc oxide nanowires is demonstrated at room temperature. Near-field optical microscopy images quantify the localization and the divergence of the laser beam. The linewidths, wavelengths, and power dependence of the nanowire emission characterize the nanowire as an active optical cavity. These individual nanolasers could serve(More)
Luminescent markers play a key role in imaging techniques for life science since they provide a contrast mechanism between signal and background. We describe a new type of marker using second harmonic generation (SHG) from noncentrosymmetric BaTiO 3 nanocrystals. These nanoparticles are attractive due to their stable, non-saturating and coherent signal with(More)
Third harmonic generation (THG) imaging using a near-field scanning optical microscope (NSOM) is demonstrated for the first time. A femtosecond, tunable near-infrared laser was used to generate both nonresonant and resonantly enhanced third harmonic radiation in human red blood cells. We show that resonantly enhanced THG is a chemically specific bulk probe(More)
Many remarkable semiconductor-based nanolaser cavities using metal have been reported in past few years. However, the efficient coupling of these small cavities to waveguides still remains a large challenge. Here, we show highly efficient coupling of a semiconductor-based metal-clad nanolaser cavity operating in the fundamental dielectric cavity mode to a(More)
We present the first results from studies of liquid water microjets by soft X-ray absorption spectroscopy. Near the oxygen K-edge (∼530 eV) a fine-structure pattern very similar to that found for gaseous water monomers is observed when the surface-selective total ion yield (TIY) is measured, but a broadened and blue-shifted spectrum emerges when detecting(More)