Searched for: subject%3A%22optical%22
(1 - 18 of 18)
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Hei, K. (author), Shi, Guang (author), Hänsel, A. (author), Deng, Z. (author), Latkowski, Sylwester (author), Van Den Berg, Steven A. (author), Bente, Erwin (author), Bhattacharya, N. (author)
The measurement of distance plays an integral part in many aspects of modern societies. In this paper an integrated mode-locked laser on a chip is used for distance measurement based on mode-resolved interferometry. The emission from the on-chip source with a repetition rate of 2.5 GHz and a spectral bandwidth of 3 nm is coupled into a...
journal article 2019
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Elkhuizen, W.S. (author), Dore-Callewaert, T.W.J. (author), Leonhardt, Emilien (author), Vandivere, Abbie (author), Song, Y. (author), Pont, S.C. (author), Geraedts, Jo M.P. (author), Dik, J. (author)
A seventeenth-century canvas painting is usually comprised of varnish and (translucent) paint layers on a substrate. A viewer’s perception of a work of art can be affected by changes in and damages to these layers. Crack formation in the multi-layered stratigraphy of the painting is visible in the surface topology. Furthermore, the impact of...
journal article 2019
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Mayer, F. (author), Tiruvadi Krishnan, S. (author), Schuhle, DT (author), Eliseeva, Svetlana V. (author), Petoud, Stephane (author), Toth, Eva (author), Djanashvili, K. (author)
Self-aggregating calix[4]arenes carrying four DOTA ligands on the upper rim for stable complexation of paramagnetic GdIII-ions have already been proposed as MRI probes. In this work, we investigate the luminescence properties of TbIII-DOTA-calix[4]arene-4OPr containing four propyl-groups and compare them with those of the analog substituted with...
journal article 2018
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Ghaderi, M. (author), Karimi Shahmarvandi, Ehsan (author), Wolffenbuttel, R.F. (author)
The design and fabrication of wideband mid-infrared metamaterial absorbers are presented. The emphasis is put on the shape-tolerant design for using masked UV (i-line) lithography and CMOS-compatible fabrication to enable on-chip co-integration with detector and readout circuits in a MEMS foundry while maintaining wafer throughput. The...
journal article 2018
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Yazdan Mehr, M. (author), van Driel, W.D. (author), De Buyl, Francois (author), Zhang, Kouchi (author)
Degradation mechanisms of silicone plates under harsh environment conditions are studied in this investigation. Environmental degradation of silicone free form, used as secondary optics in Light Emitting Diode LED lighting lamps and luminaires or any other applications requiring high quality optics being used, has negative implications for the...
journal article 2018
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Strauch, M. (author), Somers, P.A.A.M. (author), Bociort, F. (author), Urbach, Paul (author)
A technique to create aspheric surface shapes on commercially available electrowetting liquid lenses is demonstrated. Based on a previously published surface oscillation model a technique using a Hankel transform is proposed and tested experimentally. An alternating actuation voltage is applied to the liquid lens to stimulate surface...
journal article 2018
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Ayerden, N.P. (author), Mandon, Julien (author), Harren, Frans J.M. (author), Wolffenbuttel, R.F. (author)
Increasing demand for field instruments designed to measure gas composition has strongly promoted the development of robust, miniaturized and low-cost handheld absorption spectrometers in the mid-infrared. Efforts thus far have focused on miniaturizing individual components. However, the optical absorption path that the light beam travels...
journal article 2017
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Li, X. (author), Wei, L. (author), Poelma, René H. (author), Vollebregt, S. (author), Wei, J. (author), Urbach, Paul (author), Sarro, Pasqualina M (author), Zhang, Kouchi (author)
This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material combines the excellent optical absorption...
journal article 2016
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Copuroglu, O. (author)
Plane and crossed polarization are the two standard light modes in polarized light microscopy that are widely used to characterize crystalline and amorphous phases in cement-based materials. However, the use of the crossed polarized light mode has been found to be restrictive for studying birefringent phases quantitatively due to the extinction...
journal article 2016
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Wu, Y. (author), de Graaf, M. (author), Menenti, M. (author)
This study is to evaluate the sensitivity of Aerosol Optical Depth (AOD <i style="box-sizing: inherit; line-height: inherit; max-height: 100000px; color: rgb(34, 34, 34); font-family: Arial; font-size: 13px; text-align: justify;">τ</i>) to aerosol vertical profile and type, using the Moderate Resolution Imaging Spectroradiometer (MODIS)...
journal article 2016
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Nemati, M. (author), Loozen, G.B. (author), Van der Wekken, N. (author), Van de Belt, G. (author), Urbach, H.P. (author), Bhattacharya, N. (author), Kenjeres, S. (author)
A preliminary comparative measurement between particle imaging velocimetry (PIV) and laser speckle contrast analysis (LASCA) to study pulsatile flow using ventricular assist device in a patient-specific carotid artery phantom is reported. These full-field optical techniques have both been used to study flow and extract complementary parameters....
journal article 2015
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Lee, M.J. (author), Sun, P. (author), Charbon, E. (author)
This paper reports on the first implementation of a single-photon avalanche diode (SPAD) in standard silicon on insulator (SOI) complementary metal-oxide-semiconductor (CMOS) technology. The SPAD is realized in a circular shape, and it is based on a P+/N-well junction along with a P-well guard-ring structure formed by lateral diffusion of two...
journal article 2015
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Boerkamp, M. (author), Van Leest, T. (author), Heldens, J. (author), Leinse, A. (author), Hoekman, M. (author), Heideman, R. (author), Caro, J. (author)
We present a new approach to the dual-beam geometry for on-chip optical trapping and Raman spectroscopy, using waveguides microfabricated in TripleX technology. Such waveguides are box shaped and consist of SiO2 and Si3N4, so as to provide a low index contrast with respect to the SiO2 claddings and low loss, while retaining the advantages of...
journal article 2014
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Nemati, M. (author), Presura, C.N. (author), Urbach, H.P. (author), Bhattacharya, N. (author)
Continuous health monitoring has become a major theme of our aging society. Portable devices play an important role here. Many optical portable devices are susceptible to motion induced artifacts. We have performed an experimental study for detection of fluid pulsation based on multi-exposure speckle images, in presence of motion induced...
journal article 2014
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Legrand, S. (author), Vanmeert, F. (author), Van der Snickt, G. (author), Alfeld, M. (author), De Nolf, W. (author), Dik, J. (author), Janssens, K. (author)
The development of advanced methods for non-destructive selective imaging of painted works of art at the macroscopic level based on radiation in the X-ray and infrared range of the electromagnetic spectrum are concisely reviewed. Such methods allow to either record depth-selective, element-selective or species-selective images of entire...
journal article 2014
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Mata Pavia, J. (author), Wolf, M. (author), Charbon, E. (author)
Single-photon avalanche diode (SPAD) imagers typically have a relatively low fil factor, i.e. a low proportion of the pixel’s surface is light sensitive, due to in-pixel circuitry. We present a microlens array fabricated on a 128x128 single-photon avalanche diode (SPAD) imager to enhance its sensitivity. The benefit and limitations of these...
journal article 2014
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Hulsken, B. (author), Vossen, D. (author), Stallinga, S. (author)
Array illuminators generating spots with high NA at high efficiency are presented. They are designed via application of high-NA scalar optics methods, and implemented as periodic binary phase structures. These array illuminators are used in a multi-spot scanning microscope for scanning large sample areas with a relatively high resolution.
journal article 2012
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Stallinga, S. (author)
A theory of optical trapping at low Numerical Aperture (NA) is presented. The theory offers an analytical description of the competition between the stabilizing gradient and destabilizing scattering force. The trade-off can be characterized by a single dimensionless trapping parameter, which increases with bead size to wavelength ratio ?/?, m,...
journal article 2011
Searched for: subject%3A%22optical%22
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