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Silvestri, F. (author), Feenstra, L.W. (author), Pettazzi, F. (author), Nijenhuis, J.R. (author), de Vreugd, J. (author), de Bruijn, D. (author), den Breeje, R. (author), Klop, W.A. (author), Ferrario, I. (author)High throughput optical satellite communication (SATCOM) systems need to rely on effective and robust technology to enable wavelength-division multiplexing (WDM) in a commercially viable way. The main challenge to implement WDM in optical feeder links deals with the multiplexing of high power channels. Currently the levels of power required for...conference paper 2022
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Silvestri, F. (author), Pettazzi, F. (author), Eschen, M. (author), Boschma, J.J. (author), Lutgerink, J.B. (author), Kramer, G.F.IJ. (author), Korevaar, W.C. (author), den Breeje, R. (author), Duque, C.M. (author), Doelman, N.J. (author)Optical satellite communication is growing fast and among various applications it requires higher throughput optical feeder links. Optical feeder links for satellite communication necessitate very high data throughput, up to 1 Terabit/s and beyond. Amongst several multiplexing strategies, dense wavelength division holds a key position to enable...conference paper 2020
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Gandini, E. (author), Silvestri, F. (author), Benini, A. (author), Gerini, G. (author), Martini, E. (author), Maci, S. (author), Vigano, M.C. (author), Toso, G. (author), Monni, S. (author)The design and experimental validation of a wide scanning dome antenna with reduced profile is presented. The antenna is based on the combination of a planar phased array with limited scanning capabilities and a dielectric lens which allows to broaden the field of view. The angular variation of the scan loss can be almost arbitrarily designed if...article 2020
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Stoevelaar, L.P. (author), Berzins, J. (author), Silvestri, F. (author), Fasold, S. (author), Zangeneh Kamali, K. (author), Knopf, H. (author), Eilenberger, F. (author), Setzpfandt, F. (author), Pertsch, T. (author), Bäumer, S.M.B. (author), Gerini, G. (author)We present a planar spectro-polarimeter based on Fabry-Pérot cavities with embedded polarization-sensitive high-index nanostructures. A 7 μm-thick spectro-polarimetric system for 3 spectral bands and 2 linear polarization states is experimentally demonstrated. Furthermore, an optimal design is theoretically proposed, estimating that a system...article 2020
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Nagarajan, A. (author), Siemons, M. (author), Stoevelaar, L.P. (author), Silvestri, F. (author), Achanta, V.G. (author), Bäumer, S.M.B. (author), Gerini, G. (author)In this paper, we discuss the setup of a confocal nanoscope in reflection using a super-oscillatory lens (SOL)which offers a sub-diffracted focal spot with an ultra-short depth of focus (≈100 nm). A tolerance of 20 nm defocussing in a 10 μm travel range is thus necessary, translating to an alignment requirement of the stage, with respect to the...conference paper 2019
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Human, J.D. (author), Petersson, H.I.M. (author), Ferrario, I. (author), den Breeje, R. (author), Klop, W.A. (author), Pettazzi, F. (author), Silvestri, F. (author), Gruber, J.M. (author), Saathof, R. (author), Moens, T.M.N. (author), Russchenberg, T. (author), de Lange, T.J. (author), Spierdijk, J.P.F. (author), Hazelebach, R.L.M. (author), Kuiper, S. (author), Scheffers, P.I. (author), Korevaar, C.W. (author)To overcome data rate limitations of RF communication links with satellites, TNO and Airbus Netherlands envision optical free-space communication feeder links for next generation high throughput satellites. This poster presents a feasibility assessment of such links and the technology needed by means of a link budget and a turbulence model of...other 2019
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de Lange, T.J. (author), de Man, H. (author), de Bruijn, D. (author), Hazelebach, R.L.M. (author), Rijnbeek, R.A. (author), Baeten, M.J.J. (author), Silvestri, F. (author), Human, J.D. (author), Witvoet, G. (author), Crowcombe, W.E. (author)LEOCAT is an optical head for intersatellite communication currently under development by TNO (ESA ARTES contract). The objective of LEOCAT is to develop a low recurring cost low SWAP (Size Weight and Power) optical head for the optical satellite communication constellation market. The aim of LEOCAT is to achieve a data-rate of 10Gbit/s over a...other 2019
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Stoevelaar, L.P. (author), Cernigoj, J. (author), Berzinš, J. (author), Silvestri, F. (author), Gerini, G. (author)In this paper, an all-dielectric metasurface for surface enhanced Raman spectroscopy (SERS) is presented. The proposed design constitutes of an array of silicon (Si) dimers on top of thin film of silicon nitride (SiN), deposited on a glass substrate. The coupling mechanism between the dimers is based on two orthogonal guided waves in the SiN...conference paper 2019
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Gandini, E. (author), Silvestri, F. (author), Benini, A. (author), Gerini, G. (author), Martini, E. (author), MacI, S. (author), Viganò, M.C. (author), Toso, G. (author), Monni, S. (author)A wide scanning dome antenna with reduced profile is presented in this contribution. The minimum height of the dielectric lens is derived from its geometrical configuration and imposed in the design. The antenna is analysed using in-house ray tracing and physical optics tools. Because of the presence of the lens, the phase distribution of the...conference paper 2019
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Nagarajan, A. (author), Stoevelaar, L.P. (author), Silvestri, F. (author), Siemons, M. (author), Achanta, V.G. (author), Bäumer, S.M.B. (author), Gerini, G. (author)A superoscillatory lens (SOL) is known to produce a sub-diffraction hotspot that is useful for high-resolution imaging. SOLs have not yet been directly used in a confocal reflection setup, as the SOL suffers from poor imaging properties. Additionally, the illuminating intensity distribution of the SOL still has high-intensity rings called...article 2019
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Berzins, J. (author), Silvestri, F. (author), Gerini, G. (author), Setzpfandt, F. (author), Pertsch, T. (author), Bäumer, S.M.B. (author)Digital imaging has been steadily improving over the past decades and we are moving towards a wide use of multi- and hyperspectral cameras. A key component of such imaging systems are color filter arrays, which define the spectrum of light detected by each camera pixel. Hence, it is essential to develop a variable, robust and scalable way for...conference paper 2018
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Speet, B.G. (author), Silvestri, F. (author), Gerini, G. (author), Mashaghi Tabari, S. (author), Sadeghian Marnani, H. (author)In this contribution, we present the application of an optical metasurface polarization rotator in an Atomic Force Microscopy (AFM) setup. In AFM, the laser beam used to measure the cantilever deflection is not entirely intercepted by the cantilever surface. Consequently, the remainder of the beam illuminates part of the surface under...conference paper 2018
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Černigoj, J. (author), Silvestri, F. (author), Stoevelaar, L.P. (author), Berzinš, J. (author), Gerini, G. (author)In this paper, we propose the use of high refractive index dimers for the realization of a surface enhanced Raman spectroscopy substrate, with an average enhancement factor comparable to plasmonic structures. The use of low loss dielectric materials is favorable to metallic ones, because of their lower light absorption and consequently a much...article 2018
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Silvestri, F. (author), Benini, A. (author), Gandini, E. (author), Gerini, G. (author), Martini, E. (author), Maci, S. (author), Vigano, M.C. (author), Geurts, M. (author), Toso, G. (author), Monni, S. (author)This paper presents design considerations for the development of wide-scanning antennas for on-craft satellite communications. A scanning coverage of 80° is required for this application over a 15% fractional bandwidth in Ka-band. A solution based on a phased array illuminating a passive superstrate is identified as the most promising. A fully...conference paper 2017
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Silvestri, F. (author), Gerini, G. (author), Gandini, E. (author), Monni, S. (author), Viganò, M.C. (author), Benini, A. (author), Martini, E. (author), Maci, S. (author), Toso, G. (author)Design considerations on a wide-scanning array antenna for on-craft satellite communications are presented in this paper. For this type of application, a scanning coverage of 80° over a 15% fractional bandwidth in Ka-band is required. A solution based on a passive superstrate illuminated by a phased array is recognized as the most encouraging....conference paper 2017
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Gandini, E. (author), Silvestri, F. (author), Benini, A. (author), Gerini, G. (author), Martini, E. (author), Maci, S. (author), Viganò, M.C. (author), Toso, G. (author), Monni, S. (author)In this contribution, a dielectric dome antenna design in Ka-band is presented. The dome antenna is based on the combination of a phased array and a dielectric lens. The goal of the combination of these structures is to enlarge the field of view of the antenna. In particular, the array is considered to be able to scan up to 60º and the lens is...conference paper 2017
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Silvestri, F. (author), Gerini, G. (author), Bäumer, S.M.B. (author)In the last years, much interest has grown around the concept of optical surfaces employing high contrast dielectric resonators. However, a systematic approach for the design of this optical surfaces under particular requirements has never been proposed. In this contribution, we describe this approach applied to the robust design of an array of...conference paper 2017
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Silvestri, F. (author), Gerini, G. (author), Bäumer, S.M.B. (author), van Zwet, E.J. (author)In this paper, we present a design strategy for single layer metasurface lenses based on dielectric resonators. This strategy is based on a robust optimization procedure for the resonator distribution in order to meet required performances (e.g. encircled energy, bandwidth, field of view, etc.). Possible deviations due to manufacturing errors are...article 2016
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Silvestri, F. (author), Bernal Arango, F. (author), Vendel, K.J.A. (author), Gerini, G. (author), Bäumer, S.M.B. (author), Koenderink, A.F. (author)This paper presents the use of optical antennas in metrology scenarios. Two design concepts are presented: dielectric nanoresonator arrays and plasmonic nanoantennas arrays. The first ones are able to focus an incident light beam at an arbitrary focal plane. The nanoantennas arrays can be employed for collecting the high-spatial frequencies of...conference paper 2016
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Silvestri, F. (author), Cifola, L. (author), Gerini, G. (author)In this paper, we present the full process of designing anisotropic metamaterial (MM) wide angle impedance matching (WAIM) layers. These layers are used to reduce the scan losses that occur in active phased arrays for large scanning angles. Numerical results are provided to show the improvement in performances that such layers can ensure. The...article 2016
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