arXiv subjects

A. Femius Koenderink

Publications and source records attributed to A. Femius Koenderink.

46 records · Page 3Linked to original sources

arXiv2011

Fourier microscopy of single plasmonic scatterers

We report a new experimental technique for quantifying the angular distribution of light scattered by single plasmonic and metamaterial nanoscatterers, based on Fourier microscopy in a dark field confocal set up. This new set up is a necessary tool for quantifying the scattering properties of single plasmonic and meatamaterial building blocks, as well as small coupled clusters of such building blocks, which are expected to be the main ingredients of nano-antennas, light harvesting structures and transformation optics. We present a set of measurements on Au nanowires of different lengths and show how the radiation pattern of single Au nanowires evolve with wire length and as a function of driving polarization and wave vector.

physics.optics↗

arXiv2011

Scanning emitter lifetime imaging microscopy for spontaneous emission control

We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nano-photonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment while measuring its lifetime. We demonstrate the method by imaging the enhancement of the local density of optical states around metal nanowires. By nano-positioning, the decay rate of a pointlike source of fluorescence can be reversibly and repeatedly changed by a factor of two by coupling it to the guided plasmonic mode of the wire.

physics.optics↗

arXiv2011

Broad-band coherent backscattering spectroscopy of the interplay between order and disorder in 3D opal photonic crystals

We present an investigation of coherent backscattering of light that is multiple scattered by a photonic crystal by using a broad-band technique. The results significantly extend on previous backscattering measurements on photonic crystals by simultaneously accessing a large frequency and angular range. Backscatter cones around the stop gap are successfully modelled with diffusion theory for a random medium. Strong variations of the apparent mean free path and the cone enhancement are observed around the stop band. The variations of the mean free path are described by a semi-empirical three-gap model including band structure effects on the internal reflection and penetration depth. A good match between theory and experiment is obtained without the need of additional contributions of group velocity or density of states. We argue that the cone enhancement reveals additional information on directional transport properties that are otherwise averaged out in diffuse multiple scattering.

cond-mat.mes-hall↗

arXiv2010

Dynamically reconfigurable directionality of plasmon-based single photon sources

We propose a plasmon-based reconfigurable antenna to controllably distribute emission from single quantum emitters in spatially separated channels. Our calculations show that crossed particle arrays can split the stream of photons from a single emitter into multiple narrow beams. We predict that beams can be switched on and off by switching host refractive index. The design method is based on engineering the dispersion relations of plasmon chains and is generally applicable to traveling wave antennas. Controllable photon delivery has potential applications in classical and quantum communication.

physics.optics↗

arXiv2009

Orientation-dependent spontaneous emission rates of a two-level quantum emitter in any nanophotonic environment

We study theoretically the rate of spontaneous emission of a two-level quantum emitter embedded in realistic systems: near a mirror, near a plasmonic sphere, or in a 3D photonic bandgap crystal. At constant frequency and position, we find striking (up to $10^{2}\times$) variations in emission rate by varying the orientation of the transition dipole moment. We present a general representation of rate versus orientation that only invokes symmetry of the Green function. The concomitant 3-dimensional geometric surfaces provide much insight in how preferred orientations for enhancement (or inhibition) depend on the emitter's frequency and location, and on optimal strategies to actively switch emission rates by controlling oriented dipoles.

physics.optics↗

arXiv2009

Accurate calculation of the local density of optical states in inverse-opal photonic crystals

We have investigated the local density of optical states (LDOS) in titania and silicon inverse opals -- three-dimensional photonic crystals that have been realized experimentally. We used the H-field plane-wave expansion method to calculate the density of states and the projected local optical density of states, which are directly relevant for spontaneous emission dynamics and strong coupling. We present the first quantitative analysis of the frequency resolution and of the accuracy of the calculated local density of states. We have calculated the projected LDOS for many different emitter positions in inverse opals in order to supply a theoretical interpretation for recent emission experiments and as reference results for future experiments and theory by other workers. The results show that the LDOS in inverse opals strongly depends on the crystal lattice parameter as well as on the position and orientation of emitting dipoles.

physics.optics↗

arXiv2008

Fractional decay of quantum dots in real photonic crystals

We show that fractional decay may be observable in experiments using quantum dots and photonic crystals with parameters that are currently achievable. We focus on the case of inverse opal photonic crystals and locate the position in the crystal where the effect is most pronounced. Furthermore, we quantify the influence of absorptive loss and show that it is a limiting but not prohibitive effect.

quant-ph↗

arXiv2007

Strongly nonexponential time-resolved fluorescence of quantum-dot ensembles in three-dimensional photonic crystals

We observe experimentally that ensembles of quantum dots in three-dimensional (3D) photonic crystals reveal strongly nonexponential time-resolved emission. These complex emission decay curves are analyzed with a continuous distribution of decay rates. The log-normal distribution describes the decays well for all studied lattice parameters. The distribution width is identified with variations of the radiative emission rates of quantum dots with various positions and dipole orientations in the unit cell. We find a striking sixfold change of the width of the distribution by varying the lattice parameter. This interpretation qualitatively agrees with the calculations of the 3D projected local density of states. We therefore conclude that fluorescence decay of ensembles of quantum dots is highly nonexponential to an extent that is controlled by photonic crystals.

physics.optics↗

arXiv2005

Optical extinction due to intrinsic structural variations of photonic crystals

Unavoidable variations in size and position of the building blocks of photonic crystals cause light scattering and extinction of coherent beams. We present a new model for both 2 and 3-dimensional photonic crystals that relates the extinction length to the magnitude of the variations. The predicted lengths agree well with our new experiments on high-quality opals and inverse opals, and with literature data analyzed by us. As a result, control over photons is limited to distances up to 50 lattice parameters ($\sim 15 μ$m) in state-of-the-art structures, thereby impeding large-scale applications such as integrated circuits. Conversely, scattering in photonic crystals may lead to novel physics such as Anderson localization and non-classical diffusion.

physics.optics↗

arXiv2005

Spontaneous emission in the near-field of 2D photonic crystals

We show theoretically that photonic crystal membranes cause large variations in the spontaneous emission rate of dipole emitters, not only inside but also in the near-field above the membranes. Our three-dimensional finite difference time-domain calculations reveal an inhibition of more than five times and an enhancement of more than ten times for the spontaneous emission rate of emitters with select dipole orientations and frequencies. Furthermore we demonstrate theoretically, the potential of a nanoscopic emitter attached to the end of a glass fiber tip as a local probe for mapping the large spatial variations of the photonic crystal local radiative density of states. This arrangement is promising for on-command modification of the coupling between an emitter and the photonic crystal in quantum optical experiments.

cond-mat.other↗