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van der Sijs, T.A. (author), El Gawhary, O. (author), Urbach, Paul (author)We present the realization of a vectorial perturbation method based on the Born series applied to strong electromagnetic scattering problems. We present the general theoretical formalism and show a semianalytical implementation for scattering by diffraction gratings. We are particularly interested in the strong scattering regime, where the Born...journal article 2024
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Zhu, Z. (author), Zhang, Yu Quan (author), Adam, A.J.L. (author), Min, Changjun (author), Urbach, Paul (author), Yuan, Xiaocong (author)Stable optical trapping of gold nanoparticles is essential and desirable because of its wide applications in nanotechnology. While several factors have been proposed to affect optical trapping stability, the sample's volume fraction during optical trapping has often been neglected. To address this, by utilizing the effective medium theory, we...journal article 2023
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Schlatt, Vincent (author), Guggenberger, Tobias (author), Schmid, J. (author), Urbach, Nils (author)Blockchain-based systems become increasingly attractive targets for cybercrime due to the rising amount of value transacted in respective systems. However, a comprehensive overview of existing attack vectors and a directive discussion of resulting research opportunities are missing. Employing a structured literature review, we extract and...journal article 2023
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Heemels, A.N.M. (author), Adam, A.J.L. (author), Urbach, Paul (author)When redistributing the light emitted by a source into a prescribed irradiance distribution, it is not guaranteed that, given the source and optical constraints, the desired irradiance distribution can be achieved.We analyze the problem by assuming an optical black box that is shift-invariant, meaning that a change in source position does not...journal article 2023
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Zhu, Z. (author), Zhang, Y. (author), Zhang, Shuoshuo (author), Adam, A.J.L. (author), Min, Changjun (author), Urbach, Paul (author), Yuan, Xiaocong (author)Nonlinear responses of nanoparticles induce enlightening phenomena in optical tweezers. With the gradual increase in optical intensity, effects from saturable absorption (SA) and reverse SA (RSA) arise in sequence and thereby modulate the nonlinear properties of materials. In current nonlinear optical traps, however, the underlying physical...journal article 2023
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Dwyer, Bo L. (author), Rodgers, Lila V.H. (author), Urbach, Elana K. (author), Bluvstein, Dolev (author), Sangtawesin, Sorawis (author), Zhou, Hengyun (author), Nassab, Yahia (author), Fitzpatrick, Mattias (author), Dobrovitski, V.V. (author)Understanding the dynamics of a quantum bit's environment is essential for the realization of practical systems for quantum information processing and metrology. We use single nitrogen-vacancy (NV) centers in diamond to study the dynamics of a disordered spin ensemble at the diamond surface. Specifically, we reduce the density of "dark...journal article 2022
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Chang, J. (author), Los, Johannes W.N. (author), Gourgues, Ronan (author), Steinhauer, Stephan (author), Dorenbos, S.N. (author), Pereira, S.F. (author), Urbach, Paul (author), Zwiller, Val (author), Esmaeil Zadeh, I.Z. (author)Shortly after their inception, superconducting nanowire single-photon detectors (SNSPDs) became the leading quantum light detection technology. With the capability of detecting single-photons with near-unity efficiency, high time resolution, low dark count rate, and fast recovery time, SNSPDs outperform conventional single-photon detection...journal article 2022
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Chang, J. (author), Los, J. W.N. (author), Tenorio Pearl, J.O. (author), Noordzij, N. (author), Gourgues, R.B.M. (author), Guardiani, A. (author), Zichi, J. R. (author), Pereira, S.F. (author), Urbach, Paul (author), Zwiller, V. (author), Dorenbos, S.N. (author), Esmaeil Zadeh, I.Z. (author)Single photon detectors are indispensable tools in optics, from fundamental measurements to quantum information processing. The ability of superconducting nanowire single photon detectors (SNSPDs) to detect single photons with unprecedented efficiency, short dead time, and high time resolution over a large frequency range enabled major...journal article 2021
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- Shao, Y. (author), Urbach, Paul (author) journal article 2021
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Grillo Peternella, F. (author), Harmsma, Peter (author), Horsten, R.C. (author), Zuidwijk, T. (author), Urbach, Paul (author), Adam, A.J.L. (author)A new method for fast, high resolution interrogation of an array of photonic sensors is proposed. The technique is based on the integrated Fourier transform (FT) interrogator previously introduced by the authors. Compared to other interferometric interrogators, the FT-interrogator is very compact and has an unprecedented tolerance to...journal article 2021
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Ji, W. (author), Cai, Tong (author), Xi, Z. (author), Urbach, Paul (author)Achromatic devices have wide application prospects in radar and imaging fields. However, chromatic aberration and limited bandwidth restrict their development. Moreover, broadband and highly efficient achromatic devices working in transmission mode are still difficult to realize. In this paper, broadband highly efficient achromatic...journal article 2021
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Wei, X. (author), Urbach, Paul (author), van der Walle, Peter (author), Coene, W.M.J.M. (author)We present a parameter retrieval method which incorporates prior knowledge about the object into ptychography. The proposed method is applied to two applications: (1) parameter retrieval of small particles from Fourier ptychographic dark field measurements; (2) parameter retrieval of a rectangular structure with real-space ptychography. The...journal article 2021
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Dou, X. (author), Pereira, S.F. (author), Min, Changjun (author), Zhang, Yuquan (author), Meng, P. (author), Urbach, Paul (author), Yuan, Xiaocong (author)The sidewall angle (SWA) of a nanostructure exerts influence on the performance of the nanostructure and plays an important role in processing nano-structural chips. It is still a great challenge to determine steep SWAs from far field measurements especially when the SWAs are close to 90°. Here, we propose a far-field detection system to...journal article 2021
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van der Sijs, T.A. (author), El Gawhary, O. (author), Urbach, Paul (author)Electromagnetic scattering is the main phenomenon behind all optical measurement methods where one aims to retrieve the shape or physical properties of an unknown object by measuring how it scatters an incident optical field. Such an inverse problem is often approached by solving, several times, the corresponding direct scattering problem and...journal article 2020
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Tang, Y. (author), Ha, S. (author), Begou, Thomas (author), Lumeau, Julien (author), Urbach, Paul (author), Dekker, N.H. (author), Adam, A.J.L. (author)The ability to apply force and torque directly to micro- and nanoscale particles in optical traps has a wide range of applications. While full control of both force and torque in three dimensions has been realized using top-down fabrication of rod-shaped particles composed of birefringent crystalline materials, widespread usage of such...journal article 2020
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Meng, P. (author), Pham, Hong Liên (author), Pereira, S.F. (author), Urbach, Paul (author)Lateral resolution enhancement is demonstrated in a confocal imaging system with amplitude-modulated radially polarized (RP) light at the wavelength Annular pupil fields and optimized amplitude distribution functions can be realized with a spatial light modulator. By comparing images obtained with full and amplitude modulated apertures of RP...journal article 2020
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Man, Z. (author), Xi, Z. (author), Yuan, Xiaocong (author), Burge, R. E. (author), Urbach, Paul (author)Carrying orbital angular momentum per photon, the optical vortex has elicited widespread interest. Here, we demonstrate that dual coaxial longitudinal polarization vortices can appear upon a nonparaxial propagation of a tightly focused Pancharatnam-Berry tailored Laguerre-Gaussian beam. Most importantly, it is capable of accessing arbitrary...journal article 2020
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Ansuinelli, P. (author), Coene, W.M.J.M. (author), Urbach, Paul (author)The development of actinic mask metrology tools represents one of the major challenges to be addressed on the roadmap of extreme ultra violet (EUV) lithography. Technological advancements in EUV lithography result in the possibility to print increasingly fine and highly resolved structures on a silicon wafer, however the presence of fine–scale...journal article 2020
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Kolenov, D. (author), Urbach, Paul (author), Pereira, S.F. (author)We demonstrate the far field detection of low-contrast nanoparticles on surfaces using a technique that is based on evanescent-wave amplification due to a thin dielectric layer that is deposited on the substrate. This research builds upon earlier results where scattering enhancement of 200 nm polystyrene (PSL) particles on top of a glass...journal article 2020
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Meng, P. (author), Pereira, S.F. (author), Dou, X. (author), Urbach, Paul (author)Improving the image quality of small particles is a classic problem and especially challenging when the distance between particles are below the optical diffraction limit. We propose a imaging system illuminated with radially polarized light combined with a suitable substrate that contains a thin dielectric layer to demonstrate that the...journal article 2020