Scattering of light in the presence of nano-structured materials, i.e. with features in the order of the wavelength of the light or smaller, reveals details of how light interacts with matter at... Show moreScattering of light in the presence of nano-structured materials, i.e. with features in the order of the wavelength of the light or smaller, reveals details of how light interacts with matter at the nanoscale. In this dissertation we present four cases of light scattering on nano-structures. First we describe how light confined in 2D structures, namely a dielectric membrane and a metal layer, interacts with either a single nano-hole or a hole-array. Then, we study two cases of light propagating in random scattering media: we show how phase modulation can be used to measure scattering properties in a volume scatterer (e.g. white paint), and we investigate light transport in a rough thin-film silicon solar cell. Show less
Gold nanorods are ideal candidates for complementing fluorophores in labelling applications. The presence of the surface plasmon resonance generates large absorption and scattering cross sections,... Show moreGold nanorods are ideal candidates for complementing fluorophores in labelling applications. The presence of the surface plasmon resonance generates large absorption and scattering cross sections, thus making the detection of single nanoparticles possible under a light microscope. The plasmon of gold nanorods depends on the ratio between their width and length and covers the range between 540nm for spheres and even above 800nm for elongated particles, thus almost the entire visible and near-infrared spectrum. The surface plasmon presents great opportunities in (bio-)sensing, enhanced spectroscopies, photothermal therapy and for concentrating light below the diffraction limit. Show less
A surface plasmon is light that is bound to a metal surface. The main merit of a surface plasmon is that is provides confinement below the diffraction limit. In this thesis, we first study the... Show moreA surface plasmon is light that is bound to a metal surface. The main merit of a surface plasmon is that is provides confinement below the diffraction limit. In this thesis, we first study the excitation and scattering of surface plasmons by subwavelength holes in the metal. Thereafter we show that an array of these hole acts as a surface plasmon laser when the surface plasmons are sufficiently amplified using a semiconductor gain medium Show less
This dissertation contains scientific research within the realm of quantum optics, which is a branch of physics. An experimental and theoretical study is made of two-photon interference phenomena... Show moreThis dissertation contains scientific research within the realm of quantum optics, which is a branch of physics. An experimental and theoretical study is made of two-photon interference phenomena in various optical systems. Spatially entangled photon pairs are produced via the nonlinear optical process of spontaneous parametric down-conversion. These entangled photons are then passed through different optical systems to study various aspects of two-photon interference. Firstly, an experimental analysis is made of the high-dimensional entanglement that is present in the orbital angular momentum of the photons. Secondly, we present a comprehensive description of two-photon quantum interference behind a double slit. We demonstrate how to control the quantum correlations and present the first observations of complete two-photon diffraction patterns behind a double slit. Finally, we present pioneering experiments on spatially entangled two-photon states that are scattered of random media. We have observed and theoretically analyzed the structure in the random two-photon interference patterns called two-photon speckle patterns. Spatial entanglement gives two-photon speckle a much richer structure than ordinary one-photon speckle. Our experiments also demonstrate a two-photon interference phenomenon that survives averaging over different realizations of disorder. The latter results are closely related to bosonic, fermionic, and anyonic particle exchange symmetries. Show less
The initial goal of this thesis was to demonstrate chaos in an open two-mirror resonator. We have designed a bifocal mirror that forms a resonator with an unstable inner and a stable outer part. To... Show moreThe initial goal of this thesis was to demonstrate chaos in an open two-mirror resonator. We have designed a bifocal mirror that forms a resonator with an unstable inner and a stable outer part. To be able to distinguish phenomena unique for configuration from phenomena also present in conventional resonators, i.e., roughness-induced scattering and aberrations, the performance of a conventional stable resonator is investigated first. Roughness-induced scattering turns out to affect the cavity finesse as well as the average power throughput and produces mode coupling close to frequency-degenerate points. We demonstrate, furthermore, a method to accurately determine aberrations by measuring the Gouy phase of subsequent higher-order modes around frequency-degeneracy. The bifocal mirror is not fabricated by traditional grinding and polishing, but by diamond-machining. The eigenmodes of a resonator with one diamond-machined bifocal mirror turn out to be Laguerre-Gaussian. We demonstrate furthermore, the coupling of two resonators based on transmission spectra and patterns, and report on the ability of the configuration to fulfill the basic requirements to obtain chaos. Show less
