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Efficiently transducing microwave signals into optical signals is one of the major demands in modem telecommunication. Electro-optical crystals hosting optical whispering gallery modes incorporated in a properly designed microwave cavity emerge as a promising candidate towards much more efficient microwave-to-light transducer [1, 2]. Here, we propose to use a ferroelectric crystal close to its paraelectric-ferroelectric...
Neutral atoms trapped inside an optical cavity provide an ideal platform for the implementation of quantum networks [1]. In such a network, nodes containing multiple atomic qubits are essential for the construction of a quantum repeater as they allow for entanglement swapping and thus the generation of entanglement between qubits over long distances. Here we will show the realisation of such a multi-qubit...
The study of the evolution of quantum states performed with photonic techniques, commonly requires the use of complex interferometric schemes [1]. Here we present a novel setup based on multipass bulk interference that allows to recreate and measure different kinds of quantum state evolutions, passing from sequential maps to quantum walks.
Optically active spins in solid-state are of interest for their potential use in a variety of future technologies. These range from quantum information processors to magnetic and electric field sensors at the nanoscale. Typically, dark paramagnetic spins in the solid-state host lattice cause quantum decoherence of the bright spin of interest. However, if these dark spins can be brought under control...
Quantum state engineering has seen important developments over the last decade. The use of hybrid protocols, combining the discrete and continuous variables of light, can achieve high detection efficiencies, making them a good candidate for the production of non-classical states. Schrödinger cat states (SCSs), superpositions of two coherent states |α〉 in phase opposition (ψcat) 〉 |α〉 ± |-α〉), constitute...
Complete control of individual atoms trapped in far-off resonance optical tweezers is vital for gaining a better understanding of the microscopic world. It will provide a platform with unprecedented flexibility for studying few-body physics, and might lead to new quantum technologies.
Hybridized nanostructures composed by metals and dielectrics, semiconductors or organics offer new opportunities achieving new functionalities in nonlinear optics, plasmonics, sensing [1-4]. In particular GaAs-AlGaAs-GaAs core-shell-supershell nanowires (NWs) fabricated by self-catalyzed growth on Si substrates were partially covered with gold, thus producing a symmetry breaking in the sample geometry...
Optical rectification of ultrashort laser pulses in electro-optic crystals is an established technique of terahertz generation. In this technique, the pump optical pulse produces a nonlinear polarization that moves with the group velocity of the optical pulse and acts as a source of terahertz radiation. The up-to-date generation schemes based on this principle utilize both the standard collinear phase...
The nonlinear light-matter interaction lies at the heart of controlling the electronic systems for the purpose of developing ultrafast optical switching and modulation devices [1], and attosecond laser technology [2]. In general, the interaction causes the formation of photon dressed state that is a quantum superposition state with energetically spaced sidebands and enables to generate the phase-locked...
Two-dimensional transition metal dichalcogenide (MX2) are receiving lot of attention in recent years due to their excellent electronic and optical properties which make them feasible for advanced photonics applications [1]. In particular Molybdenum-Disulfide (MoS2) has shown large exciton binding energy, strong spin-orbit interaction, and high carrier mobilities.
We study surface plasmons on hexagonal hole arrays in gold on actively-pumped semiconductor. The observed dispersion yields the angle-dependent scattering. Lasing occurs in a radially-polarized donut beam and a hexagonal mode with mixed radial/azimuthal polarization.
For memory applications and optical control of qubits ultrafast manipulation and high coupling efficiencies are desirable. Ultrafast coherent control can be achieved by the off-resonant Raman scheme [1]. There exist several colour centres with an optically accessible lambda-type energy structure which offer a level splitting large enough for broadband laser pulses.
In a biaxial biréfringent crystal there are two directions at which the refractive index surfaces intersect, leading to the phenomenon of conical refraction [1]. These conical intersections are analogs of Dirac points, and are generically present in non-chiral optical materials. One of the most interesting aspects of Dirac points is that they carry an associated topological charge. As such the propagation...
The Optical Frequency Comb (OFC) represents a cornerstone of precision metrology, because it provides a clockwork to down-convert hundreds of THz of optical frequency standards to the countable and traceable radio frequency (RF) domain. In particular, for a future redefinition of the Coordinated Universal Time by an optical atomic transition [1], it will be an essential ingredient. Nowadays, narrowband...
Fibers are considered as extraordinary tabletop laboratories to investigate optical turbulence and optical rogue waves (ORW). However ultrafast measurement of random optical power fluctuations is a challenging experimental task and the typical sub-picosecond timescale prevented-up to now-time-resolved observations of the awaited dynamics. We report the first single-shot recordings of ORW emerging...
Gold nanosponges are gold/air percolated nanoparticles with three dimensionally intertwined gold and air filaments of sub-20 nm diameter. The internal structure of the nanosponges, i.e. the size of the gold and air filaments can be tuned by varying the fabrication parameters [1]. Gold nanosponges exhibit multiple scattering resonances in the visible to NIR spectral range. Using dark field optical...
The advent of elastic optical networking, enabled by the adoption of the flexible channel grid and programmable/multi-flow transmission systems allows a dynamic management of optical networks. Multicarrier modulation (MCM), such as orthogonal frequency division multiplexing (OFDM), arises as a suitable technology for increasing flexibility and advanced functionalities, thanks to its super-/sub-wavelength...
Compared to the lithographic realization of nano-structures for microelectronics the demands of today's optical applications on the lithographic fabrication technologies are different. This relates to the lateral shape of the structures as well as to their three dimensional surface profile and, last but not least, the substrates on which the structure need to be realized. On the other hand, optical...
Nitrogen vacancy (NV) centres are a type of defect in diamond that exhibit a number of interesting properties. NV centres can be optically excited around 450–650 nm and emit fluorescence at around 550–800 nm [1]. The optical excitation also spin polarises the negatively charged NV centres, permitting optical detection of magnetic resonance [2]. This allows nanotesla scale sensitive magnetometry to...
Promising potential of several novel ternary crystals (TI4YXS3, Y=Sn, Pb; X=S, Te) for applications in infrared (IR) optoelectronics, LEDs (light emitting diodes) and photodetectors operating in the middle and far IR spectral ranges has been demonstrated in the present work. Besides, these materials can be used as thermoelectric materials [1], IR harmonic frequency triggers, modulators, optical memory...
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