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Nanophotonics focuses on the control of light and the interaction with matter by the aid of intricate nanostructures. Typically, a photonic nanostructure is carefully designed for a specific application and any imperfections may reduce its performance, i.e., a thorough investigation of the role of unavoidable fabrication imperfections is essential for any application. However, another approach to...
Semiconductor quantum dots have improved their optical performance dramatically in recent years, and today a clear pathway is laid out for constructing a deterministic and coherent photon-emitter interface by embedding quantum dots in photonic nanostructures [1]. Such an interface can be employed as an on-demand single-photon source for quantum-information applications, but more generally enables...
We present recent progress on the development of nano-opto-electromechanical systems (NOEMS) for solid-state quantum photonics and discuss the application of optical switching networks for de-multiplexing single photons generated by semiconductor quantum dots.
We present theory and measurements for systematically disordered slow-light photonic crystal waveguides and find a pronounced disorder-induced blueshift and broadening of the photon density of states.
Photonic-crystal waveguides are excellent model systems to investigate band-gap related phenomena in condensed matter physics. An example is the effect of disorder on the band edge. Even for state-of-the-art systems, the smallest effects of disorder are enhanced in the so-called slow-light regime, eventually leading to Anderson localization and, hence, breakdown of the transport of light. We employ...
A very smooth lasing transition in photonic crystal nanocavities with embedded quantum dots is observed and compared to the theory. Decay rate measurements reveal that only a few quantum dots are feeding the cavity.
All-solid-state cavity quantum electrodynamics (CQED) systems based on quantum dots (QDs) in nanophotonic cavities provide a promising platform for practical implementations of quantum information protocols. The ability to enter the coherent-coupling regime was demonstrated by recording detuning-dependent emission spectra [1] proving that the QD-cavity coupling is so strong that there is ‘memory’...
Disorder in photonic-crystal slab waveguides can cause localization of light [1, 2]. Sapienza et al. observed that the interaction of localized light with embedded quantum dots is so strong that it yields a considerable Purcell enhancement of the emission rate [3]. This coupling between emitters and these “random cavities” warrants a more detailed investigation.
Wave propagation through multiple scattering media has been an active research field since the discovery of Anderson localization [1]. This interest has amongst other resulted in the discovery of classical wave phenomena such as enhanced coherent back scattering [2] and universal conductance fluctuations [3]. Only recently focus has reached the combination of quantum optics and multiple scattering,...
Semiconductor cavity quantum electrodynamical (CQED) devices are believed to be important components for future quantum information technologies. Being composed of a single quantum dot (QD) embedded in a cavity, semiconductor CQED systems resemble atomic CQED systems. However, recent experiments [1] have demonstrated that the physics of such all-solid-state systems is much richer than their atomic...
Photonic crystal nanolasers have attracted great interest both for fundamental research and applications in the past decade. In photonic crystal cavities, the leakage to optical modes is strongly reduced, which increases the spontaneous emission coupling factor, β. This is a crucial parameter for the threshold characteristics of lasers. With increasing β, the well-known step-like threshold behavior...
Optical cavity cooling of mechanical resonators has recently become a research frontier where cooling of the vibrational motion of the resonators has been realized via photo-thermal force [1] and subsequently via radiation pressure [2–4]. One of the ultimate goals is reaching the vibrational ground state allowing quantum mechanical states of vibration - and the field offers a potential for hybrid...
We have measured the variation of the spontaneous emission rate with polarization for self-assembled single quantum dots in two-dimensional photonic crystal membranes, and obtained a maximum anisotropy factor of 6 between the decay rates of the two nondegenerate bright states.
Control over spontaneous emission of quantum dots is important for many applications, especially as light sources in photonic materials and nanostructures. Colloidal CdSe quantum dots have recently generated enormous interest because of the tunability of their emission energy with particle diameter over the entire visible range. The strength of the interaction of a quantum dot with the light field...
In this contribution we present an experiment demonstrating the generation of non-classical SPPs by exciting them with a squeezed optical light field generated using a bow-tie shaped optical parametric oscillator operating below threshold. Free space optics and end-fire coupling are used for the excitation of long-range SPPs (LR-SPPs) on gold stripes embedded in lossless transparent polymer BCB.
This work investigates the influence of dark excitons on the radiative dynamics of semiconductor quantum dots (QDs). Dark excitons have total angular momentum of 2 and contribute to the fine structure of the exciton ground state. As opposed to bright excitons that have total angular momentum 1, dark excitons cannot recombine directly via electric dipole transitions. However, slow recombination does...
In applications like quantum cryptography and quantum computation, it is desirable to obtain single photon sources which can produce a train of single photons on demand at a high repetition rate, especially at or near room temperature. Such single-photon sources can be realized by tailoring the photonic environment of the quantum emitter. The photonic environment determines the local density of states,...
Since it was realized that efficient quantum computing can be performed using single photons and standard linear optics elements, immense international research activity has been aimed at developing semiconductor quantum dot (QD) single-photon sources (SPS). In order to optimise the design of SPS for high efficiency as well as increase the understanding of the physics, advanced and accurate models...
We present time-resolved spontaneous emission measurements of a single quantum dot that is temperature tuned around the band edge of a photonic crystal waveguide. 85% efficient coupling to the slow-light waveguide mode is obtained.
The behavior of two coupled photonic crystal membrane cavities with quantum dots separated by different number of holes is investigated. The measured spectral splitting with increased coupling is verified by 3D calculations and discussed.
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