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We report progress towards multimode (MM) fibre filters for suppressing the OH emission that hinders ground-based observation of the early Universe. Fibre Bragg gratings (FBGs) can filter these narrow spectral lines in single-mode (SM) fibres [1]. Implementing them in MM fibres well-matched to astronomical instruments requires transitions between the MM fibre and several SM fibres [2]. Such hand-crafted...
We propose and demonstrate experimentally a novel type of nonlinearity in metamaterials, which is induced by mechanical deformation of the structure. The nonlinearity arises from the introduction of an extra degree of freedom in the metamaterial, which allows for elastic displacement of the strongly interacting structural elements (see Fig. 1a). This type of nonlinearity relies on the counterplay...
The advent of intense few-cycle near infrared (NIR) laser pulses with stable and tunable carrier envelope phase (CEP) has enabled the control of electromagnetic fields with attosecond time precision [1]. Here we aim at exploiting these few-cycle NIR optical fields with well-defined CEP to generate and control the motion of charge carriers within heterogeneous nanoscaled solid state interfaces. We...
Focal ratio degradation is the decrease in focal ratio (or equivalently the increase of numerical aperture) of a beam of light that has been transported through a multimode optical fibre. Multimode fibres are frequently used in astronomical instruments such as multi-object and integral field spectrographs due to the poor coupling efficiency inherent to single mode fibre use. Focal ratio degradation...
The development of integrated optical (IO) circuits for mid-IR radiation (wavelengths from ∼3 to ∼30 µm) is of significant interest for applications in bio-sensing and astronomy [1]. With specific reference to astronomy, the mid-IR spectrum is of particular interest since this is the region where objects such as planets, at earth-like temperatures, can be probed. It is also the region where biomarkers...
Integrated photonic components have demonstrated outstanding performance in beam combination for infrared astronomical interferometry [1] thanks to their exceptional thermo-mechanical stability and small physical dimensions, suitable for cryogenic assemblies. Planar photonic circuits are currently used in existing devices combining up to 4-telescopes simultaneously on all possible baselines [2], thus...
The context of this work is the development of integrated optic beam combiners devoted to stellar interferometry [1]. In the run for exoplanet detection, the 2.5–5 µm observation window has been identified as an adequate band for planet search science [2]. Besides, for spatial applications, the use of compact and light optical beam combiners ensuring robustness and stability of the interferometric...
The next generation of major ground-based optical and near-infrared astronomical telescopes are planned to have aperture sizes from 25–42 meters in diameter, making them substantially larger than existing telescopes. This has a major impact on seeing limited spectroscopic instrumentation, as the size of the instrument grows in proportion to the telescope aperture for traditional designs and more importantly,...
PIONIER (Precision Integrated Optics Near-infrared Imaging ExpeRiment) is a visitor instrument [1] that performs the interferometric beam combination in the near infrared of the light delivered by the 4 main telescopes (8m) or auxiliary telescopes (1.8m) of the VLTI on the ESO Paranal site (Chile).
Astrophotonics is the application of photonic principles to astronomical instrumentation, in order to reduce cost, size, weight and complexity while increasing performance. In astrophotonics the “photonic lantern” (PL) [1–4] is a remarkable photonic device which efficiently couples light between a multimode (MM) optical fibre and a set of degenerate single modes (SMs) which are guided by the cores...
The field of plasmonics experiences an explosive growth with a number of developing applications in biosensing, particle manipulation and photonic circuitry. This development has motivated the emerging field of plasmon optics dealing with the manipulation and engineering of plasmon beams. Airy beams represent an important class of non-diffracting wavepackets [1] which evolution in space (or time)...
At the nanoscale, the optomechanical coupling increases thanks to a reduced optical/mechanical interaction volume and reduced mass of the mechanical oscillator [1,2]. In the context of nano-optomechanics, semiconductors like GaAs offer many assets. First their large refractive index allows confining optical energy in sub-wavelentgh sized high-Q cavities. Second, nanoscale mechanical oscillators are...
The control of low-entropy quantum states of a micro-oscillator could not only allow researchers to probe quantum phenomena—such as entanglement and decoherence—at an unprecedentedly large scale, but also enable their use as interfaces in hybrid quantum systems. Preparing and probing an oscillator in the conceptually simplest low-entropy state, its quantum ground state, has now become a major goal...
In the last several years, rapid advances have been made in the field of cavity optomechanics, in which the usually feeble radiation pressure force of light is used to manipulate (and precisely monitor) mechanical motion [1–3]. These advances have moved the field from the multi-km interferometer of a gravitational wave observatory, to the optical table top, and now all the way down to a silicon microchip...
While quantum concepts like superposition and entanglement are frequently being confirmed in the lab, these concepts seem to be in blatant contradiction to our everyday experience. There, objects are always in distinct states that can be verified without disturbing the system under investigation. Is there an essential difference between macroscopic and microscopic objects, and if there is, what brings...
The coupling of light and a mechanical resonator within an optomechanical setup can have significant effects on both the light field inside the cavity and the motion of the mechanical resonator. A prominent example is the cavity assisted side-band cooling of the mechanical motion, leading to low phonon occupation and thereby approaching the quantum regime [1,2]. However, while the preparation of highly...
In the longstanding endeavor to access the quantum nature of macroscopic mechanical motion, the experimental challenge is not only that of state preparation, but also one of measurement. The flourishing field of cavity optomechanics, in which an electromagnetic resonance couples parametrically to a mechanical oscillator, addresses both of these challenges—providing a nearly ideal architecture for...
Complex multichromophoric systems that display ultrafast excitation transfer between their constituents are of great fundamental interest in technologies such as organic photovoltaics. In this study we focus on diameter enriched single-wall carbon nanotubes (CNTs) networks with a majority being of the (6,5) chirality. It has been recently found that excitation of the first excitonic transition triggers...
A special type of surface wave was predicted by M. I. Dyakonov in 1988 [1]. Such waves exist under special conditions at the interface of transparent anisotropic materials, and hens they are lossless. This surface waves require at least one of the two media to be an anisotropic medium, either biaxial or positive uniaxial, and various configurations have been investigated [2]. Recently, we reported...
Laser-driven electron emission from ultrasharp metal tips has led to a number of interesting publications in recent years [1,2]. One of the fundamental motivations for these studies is to understand laser-matter interaction at a solid state system.
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