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van Berkel, S.L. (author), Alonso Del Pino, M. (author), Jung-Kubiak, Cecile (author), Chattopadhyay, Goutam (author)
The development of a low focal number and low-mass lens antenna is presented that enables terahertz spectroscopy applications on ultracompact platforms. The antenna operates efficiently over a 20% fractional bandwidth, from 450 to 550 GHz, with a gain of 50 dBi at 500 GHz. The antenna consists of a hyperbolic silicon lens that is placed in a...
journal article 2023
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Kirchhof, Jan N. (author), Yu, Yuefeng (author), Yagodkin, Denis (author), Stetzuhn, Nele (author), de Araújo, Daniel B. (author), Kanellopulos, Kostas (author), Mañas Valero, S. (author), Coronado, Eugenio (author), van der Zant, H.S.J. (author)
Nanomechanical spectroscopy (NMS) is a recently developed approach to determine optical absorption spectra of nanoscale materials via mechanical measurements. It is based on measuring changes in the resonance frequency of a membrane resonator vs. the photon energy of incoming light. This method is a direct measurement of absorption, which has...
journal article 2023
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Mohammadi, Mohsen Doust (author), Bhaskaran, Renjith (author), Abdullah, Hewa Y. (author), Abdallah, Hassan H. (author), Biskos, G. (author), Bhowmick, Somnath (author)
We have investigated the potential energy curves (PECs) of the LiN heteronuclear diatomic molecule, including its ionic species LiN<sup>+</sup> and LiN<sup>−</sup>, using explicitly correlated multi-reference configuration interaction (MRCI-F12) calculations in conjunction with the correlation consistent quintuple-𝜁 basis set. The effect of core...
journal article 2023
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Yasin, Saima (author), Shakeel, A. (author), Ahmad, Muqarrab (author), Ahmad, Aqeel (author), Iqbal, Tanveer (author)
Polyether ether ketone (PEEK) is a semi-crystalline thermoplastic polymer having excellent mechanical and thermal properties. Exposure of this polymer to aliphatic and aromatic solvents can lead to degradation or swelling of the polymeric material. The present work described the plasticization and stability analysis of semi-crystalline PEEK...
journal article 2019
document
Bessas, D. (author), Brück, E.H. (author)
The assembly of a Lock-In digital Amplifier (LIdA) from widely accessible ready-made modules is presented. This equipment, which does not require any advanced knowledge of electronics or programming, may introduce the experimenter to resonant techniques by registering mechanical resonances. The freely available control program allows for...
journal article 2017
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Endo, A. (author), Yates, S.J.C. (author), Bueno, J. (author), Thoen, D.J. (author), Murugesan, V. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author), Van der Werf, P.P. (author), Baselmans, J.J.A. (author)
We show the first experimental results which prove that superconducting NbTiN coplanar–waveguide resonators can achieve a loaded Q factor in excess of 800 in the 350 GHz band. These resonators can be used as narrow band pass filters for on-chip filter bank spectrometers for astronomy. Moreover, the low-loss coplanar waveguide technology provides...
journal article 2016
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Endo, A. (author)
Since the birth of astrophysics, astronomers have been using free-space optics to analyze light falling on Earth. In the future however, thanks to the advances in photonics and nanoscience/nanotechnology, much of the manipulation of light might be carried out using not optics but confined waveguides, or circuits, on a chip. This new generation...
journal article 2015
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Ayerden, N.P. (author), Ghaderi, M. (author), De Graaf, G. (author), Wolffenbuttel, R.F. (author)
A set-up for optical gas composition measurement based on absorption spectroscopy is composed of a white light source, a gas cell and a spectrometer. The Fabry-Perot optical filter is suitable for miniaturization of this system, as it is composed of only two reflectors with a transparent layer in-between. Varying the width of this optical...
journal article 2014
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Broeken, J. (author), Rieger, B. (author), Stallinga, S. (author)
We propose a method for simultaneously measuring the position and emission color of single fluorescent emitters based on the use of a large pitch diffraction grating in the emission light path. The grating produces satellite spots adjacent to the main spot; the relative distance between the spots is a measure for the emission wavelength. We...
journal article 2014
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Jansen, K. (author), Wu, M. (author), Van der Steen, A.F.W. (author), Van Soest, G. (author)
Spectroscopic intravascular photoacoustic imaging (sIVPA) has shown promise to detect and distinguish lipids in atherosclerotic plaques. sIVPA generally utilizes one of the two high absorption bands in the lipid absorption spectrum at 1.2 ?m and 1.7 ?m. Specific absorption signatures of various lipid compounds within the bands in either...
journal article 2014
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Jansen, K. (author), Van der Steen, A.F.W. (author), Wu, M. (author), Van Beusekom, H.M.M. (author), Springeling, G. (author), Li, X. (author), Zhou, Q. (author), Shung, K.K. (author), De Kleijn, D.P.V. (author), Van Soest, G. (author)
The natural history of atherosclerosis is marked by changes in the lipid biochemistry in the diseased arterial wall. As lesions become more vulnerable, different cholesterol species accumulate in the plaque. Understanding unstable atherosclerosis as a pharmacological and interventional therapeutic target requires chemically specific imaging of...
journal article 2014
document
Ramakrishnan, G. (author), Kumar, N. (author), Planken, P.C.M. (author), Tanaka, D. (author), Kajikawa, K. (author)
Emission of terahertz radiation is observed when surface plasmons are excited on a thin film of gold, in the Kretschmann geometry. When a hemicyanine-terminated alkanethiol self-assembled monolayer of thickness 1.2 nm is deposited on the gold film, stronger terahertz emission is observed. Our experimental results confirm that enhanced terahertz...
journal article 2012
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Blacksberg, J. (author), Maruyama, Y. (author), Charbon, E. (author), Rossman, G.R. (author)
We incorporate newly developed solid-state detector technology into time-resolved laser Raman spectroscopy, demonstrating the ability to distinguish spectra from Raman and fluorescence processes. As a proof of concept, we show fluorescence rejection on highly fluorescent mineral samples willemite and spodumene using a 128 × 128 single-photon...
journal article 2011
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Ramakrishnan, G. (author), Planken, P.C.M. (author)
Emission of pulses of electromagnetic radiation in the terahertz range is observed when ultrathin gold films on glass are illuminated with femtosecond near-IR laser pulses. A distinct maximum is observed in the emitted terahertz amplitude from films of average thickness just above the percolation threshold. Our measurements suggest that the...
journal article 2011
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Budhysutanto, W.N. (author), Van Den Bruele, F.J. (author), Rossenaar, B.D. (author), Van Agterveld, D. (author), Van Enckevort, W.J.P. (author), Kramer, H.J.M. (author)
Donut-like crystals of Mg–Al layered double hydroxides (LDH) are synthesized using a hydrothermal method with microwave heating. This morphology provides enlargement of the specific surface area of the {h k 0} faces, needed for adsorption application. The growth mechanism for donut-shaped crystals is proposed on the basis of AFM and STEM–EDX...
journal article 2010
document
Ramakrishnan, G. (author), Chakkittakandy, R. (author), Planken, P.C.M. (author)
Generation of subpicosecond terahertz pulses is observed when graphite surfaces are illuminated with femtosecond near-infrared laser pulses. The nonlinear optical generation of THz pulses from graphite is unexpected since, in principle, the material possesses a centre of inversion symmetry. Experiments with highly oriented pyrolytic graphite...
journal article 2009
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Adam, A.J.L. (author), Planken, P.C.M. (author), Meloni, S. (author), Dik, J. (author)
We show terahertz reflection images of hidden paint layers in a painting on canvas and compare the results with X-ray Radiography and Infrared Reflectography. Our terahertz measurements show strong reflections from both the canvas/paint interface and from the raw umber/lead white interface, indicating sufficient refractive-index contrast. Our...
journal article 2009
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Adam, A.J.L. (author), Brok, J.M. (author), Seo, M.A. (author), Ahn, K.J. (author), Kim, D.S. (author), Kang, J.H. (author), Park, Q.H. (author), Nagel, M. (author), Planken, P.C.M. (author)
An erratum is presented to correct an error in the discussion section of [Opt. Express. 16, 7407-7417 (2008)] and to add a relevant reference on earlier work.
journal article 2008
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Chakkittakandy, R. (author), Corver, J.A.W.M. (author), Planken, P.C.M. (author)
We describe a simple terahertz (THz) time domain spectrometer with a bandwidth extending up to 7.5 THz. We show that by keeping the generation and detection crystals close to each other a high signal-to-noise ratio (SNR) can be achieved without using lock-in detection and dry nitrogen flushing. The observed spectra show very good agreement with...
journal article 2008
document
Adam, A.J.L. (author), Brok, J.M. (author), Seo, M.A. (author), Ahn, K.J. (author), Kim, D.S. (author), Kang, J.H. (author), Park, Q.H. (author), Nagel, M. (author), Planken, P.C.M. (author)
Using terahertz-light excitation, we have measured with sub-wavelength spatial, and sub-cycle temporal resolution the time- and frequency-dependent electric-field and surface-charge density in the vicinity of small metallic holes. In addition to a singularity like concentration of the electric field near the hole edges, we observe, that holes...
journal article 2008
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