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The unavoidable trade-off between resolution and depth of focus (DOF) limits traditional optical imaging. High numerical apertures (NA) enable to increase the resolution, but the associated large angular uncertainty results in a limited range of depths that can be put in sharp focus.
It is commonly understood that, to cast light into a state with sub-Poissonian statistics, a strong optical nonlinearity is needed. The most common examples are resonance fluorescence of a two-level system, or a Kerr medium where the Kerr energy per photon U is much larger than the optical linewidth κ. In both cases, a single-photon nonlinearity is realized, whereby the presence of a single photon...
In aperiodically poled quasi-phase-matching (QPM) crystals, parametric down-conversion (PDC) can generate very broadband pulsed squeezed light. This is because each part of the crystal will generate squeezed light at a different frequency [1]. But the emission will be thus inhomogeneously broadened, and one requires special measures to eliminate the chirp accompanying the pulses. This can be done...
Semiconductor microcavities can be engineered to produce strong coupling between photons and quantum well excitons leading to the formation of new eigenstates called polaritons. Due to their peculiar dispersion, enabling non-equilibrium Bose-Einstein condensation [1], and their straightforward experimental accessibility, microcavity polaritons have gained considerable interest in recent years. Polariton...
The use of optical frequency combs (FC) for high precision measurements is limited by fluctuations of the comb structure [1]. The FC fluctuations can be modelled as uncoupled noise modes associated with a few global parameters namely power, central wavelength, carrier-envelope offset (CEO) phase, repetition rate, dispersion [2, 3]. However, the correlations between phase and amplitude noises, which...
Manipulation of perovskite crystallinity in order to obtain the desired optoelectronic properties is a critical issue. Perovskite structural characterization has been carried out applying several tools, which usually interrogate bulky portions of the material, averaging out over the inhomogeneities at the sub-micron scale [1]. Preliminary results obtained through photoluminescence microscopy across...
Parametric downconversion (PDC) allows the generation of highly coherent, spectrally pure single photons for quantum photonics. In a typical heralded PDC source, the signal photon emerges in a spectrally mixed state due to strong (anti)correlation in the joint spectrum of PDC photon pairs.
There is always a special interest in trying to predict transitions, crisis, social revolutions, catastrophic events like the end of the world and, nowadays judging by the number of spam messages coming from clairvoyants, we strongly believe that the interest in predicting events of every type is growing fast. Almost always catastrophic events are produced when a bifurcation occurs in a dynamical...
Kerr frequency combs in passive resonators have attracted considerable interest during the last decade as a complementary approach to comb formation based on mode-locked lasers. Most of previous works have focused on monochromatic CW-pumping either with or without parametric seeding [1-3]. Here, we report on an extensive study of a dual pumping configuration in a passive nonlinear fiber ring cavity...
Quantum optics experiments require ultimate control over the propagation of light in linear optical networks to realize programmable photon correlations [1]. Integrated optics provides a robust and low-loss platform for implementing such linear optical networks. However, to achieve ultimate control on the quantum state of light, it is necessary to program the network [2]. Tuning the network for controlled...
Fibered sources of photon pairs can be easily integrated into future quantum communication networks. However, in silica-core fibres, the broadband spectrum of spontaneous Raman scattering strongly contributes to uncorrelated noise photons degrading the quality of the source. To overcome the problem of the silica Raman scattering, a new architecture was recently proposed, with hollow-core photonic...
Squeezed states of light are referred to as non-classical field states and are known to be characterized by strong correlations between photons both in the spectral and spatial domain. For these reasons they are very perspective for many important and interesting practical applications in modern quantum optics including storage and transfer of quantum information. From this point of view multiphoton...
Ghost imaging (GI) exploits the intensity correlations of light to reconstruct an object. A “ghost image” is obtained by correlating the total transmitted or reflected intensity of an illuminated object with the intensity of a highly-correlated reference beam which itself doesn't interact with the object. Intriguingly, the spatial resolution of the image is provided by the non-interacting reference...
High peak power lasers are of great importance for a wide number of applications like material processing, remote sensing and etc. The most impressive, and still record, result has been demonstrated with using of photonics crystal fibers (PCFs), where amplification to more than 1 MW peak power directly from amplifier was demonstrated [1, 2]. However such fiber are difficult in production, handling...
The emergence of long range phase coherence among random nonlinear waves is a fascinating effect that characterizes many fundamental phenomena. For instance, the condensation of classical waves [1,2] is an important example of self-organization process that generates lot of interest as a classical analogue of quantum Bose-Einstein condensation. Wave condensation is known to be characterized by the...
Quantum memories are very important in quantum communication and information as they provide a quantum interface between photons, used for long distance communication, and matter, in which stationary qubits can be stored. Moreover they are fundamental building blocks in quantum repeaters. Rare-earth doped crystals (REDC) are promising candidates for the implementation of quantum memories because of...
The physical principle of nonlocality is of particular interest both for fundamental tests of quantum theory via Bell inequality violations and for many quantum information processing applications like quantum key distribution (QKD). Over the last decades, corresponding studies have been performed mostly on the basis of two-dimensional quantum states (qubits). In order to gain a deeper insight into...
Light propagates inside an ideal and infinite photonic crystal when the Bloch condition is satisfied and any allowed light wave is decomposed in a basis of propagating Bloch waves [1]. In real photonic crystals, light propagation is modified due to unavoidable fabrication-induced structural imperfections in size, positions, and permittivity of the building blocks, as well as the finite size of the...
Spatially entangled photon states are used in experiments addressing fundamental properties of quantum mechanics as well as practical applications [1]. Thereby, the use of these states demands for time-saving detection mechanisms, capable of measuring coincidences between spatially separated photons with high spatial and temporal resolution. In this work, we demonstrate coincidence detection of spatially...
Pure and deterministic single-photon sources, obtained by coupling a semiconductor quantum dot (QD) to a photonic crystal (PhC) cavity, constitute a key component for quantum photonic integrated circuits (QPICs) [1]. These sources are commonly excited by a laser pump, which involves some practical limitations in scaling the number of integrated cavity-emitter nodes and is hardly compatible with on-chip...
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