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Efficiently coupling single-photon emitters in the telecommunication C-band that are not deterministically positioned to photonic structures requires both spatial and spectral mapping. This study introduces the photoluminescence mapping of telecom C-band self-assembled quantum dots (QDs) by confocal laser scanning microscopy, a technique previously unexplored in this wavelength range which fulfills these two requirements. We consider the effects of distortions inherent to any imaging system but largely disregarded in prior works to derive accurate coordinates from photoluminescence maps. We obtain a position uncertainty below 11 nm for 10% of the QDs when assuming no distortions, highlighting the potential of the scanning approach. After distortion correction, we found that the previously determined positions are on average shifted by 428 nm from the corrected positions, demonstrating the necessity of this correction for accurate positioning. Then, through error propagation, the position uncertainty for 10% of the QDs increases to 110 nm., QC 20240812

In this paper, we review the research and development of the fractal superconducting nanowire single-photon detectors (SNSPDs), including our demonstrations of high-performance devices and systems with over 80% system detection efficiency, negligibly low residual polarization sensitivity, and low timing jitter. Using the fractal SNSPDs, we demonstrate full-Stokes polarimetric imaging LiDAR., Part of ISBN 9781510673687QC 20240719

Full-Stokes polarimetric imaging light detection and ranging (LiDAR) provides rich information about distance, materials, texture, surface orientations, and profiles of objects, and it is an important remote-sensing technology. One major challenge to reach a long distance is to efficiently collect and detect the echo photons, as for long-range LiDAR, echo photons may become sparse. Here, we demonstrate a full-Stokes polarimetric imaging LiDAR, working at the eye-safe, telecommunication wavelength of 1560 nm, that can reach a range of 4 km. The key enabling technology is a four-channel system with multimode-fiber-coupled, large-area fractal superconducting nanowire single-photon detectors. Furthermore, we also explore faster imaging (e.g., pixel-dwell time of 1 ms) of the objects at a shorter distance, approximately 1 km. Our demonstration has significantly extended the working range of full-Stokes polarimetric imaging LiDAR and represents an important step toward practical systems that may enable many applications in remote sensing and the detection and recognition of targets., QC 20240823

We report on an eight-channel fractal SNSPD system in the wavelength range of 940 nm with minimal polarization sensitivity. The best channel exhibits 96% system detection efficiency and 19 cps dark-count rate., QC 20240612Part of ISBN 978-195717132-6

Superconducting nanowire single photon detectors (SNSPDs) made with thin NbN films can reach high performances. While sputtering has been the deposition method of choice, here, we show that ammonia-molecular beam epitaxy (NH3-MBE) can produce pertinent epitaxial cubic NbN thin films on silicon substrates using an AlN buffer. Despite granular morphology and a high density of grain boundaries as well as the presence of rotational twins, Tc = 12.7 K for a 5.6 nm thick film and saturation of internal detection efficiency up to 850 nm are achieved. Morphology and stoichiometry as well as strain have a strong impact on the detector properties, highlighting the importance of a precise control of the growth parameters. These results pave the way for high fabrication yield of SNSPDs on large-scale silicon wafers using epitaxial NbN thin films grown by MBE., QC 20240201

The Quality Assurance project for stage III non-small cell lung cancer radiotherapy ProCaLung performed a multicentric two-step exercise evaluating mediastinal nodal Target Volume Definition and Delineation (TVD) variability and the opportunity for standardization. The TVD variability before and after providing detailed guidelines and the value of qualitative contour reviewing before applying quantitative measures were investigated. The case of a patient with stage III NSCLC and involved mediastinal lymph nodes was used as a basis for this study. Twenty-two radiation oncologists from nineteen centers in Belgium and Luxembourg participated in at least one of two phases of the project (before and after introduction of ProCaLung contouring guidelines). The resulting thirty-three mediastinal nodal GTV and CTV contours were then evaluated using a qualitative-before-quantitative (QBQ) approach. First, a qualitative analysis was performed, evaluating adherence to most recent guidelines. From this, a list of observed deviations was created and these were used to evaluate contour conformity. The second analysis was quantitative, using overlap and surface distance measures to compare contours within qualitative groups and between phases. A 'most robust' reference volume for these analyses was created using the STAPLE-algorithm and an averaging method. Five GTV and seven CTV qualitative groups were identified. Second step contours were more often in higher-conformity groups (p = 0.012 for GTV and p = 0.024 for CTV). Median Residual Mean Square Distances improved from 2.34 mm to 1.36 mm for GTV (p = 0.01) and from 4.53 mm to 1.58 mm for CTV (p < 0.0001). Median Dice coefficients increased from 0.81 to 0.84 for GTV (p = 0.07) and from 0.82 to 0.89 for CTV (p ≤ 0.001). Using HC-contours only to generate references translated in more robust quantitative evaluations. Variability of mediastinal nodal TVD was reduced after providing the ProCaLung consensus guidelines. A qualitative r

Background and Objective: Quality of treatment planning and delivery in radiation oncology is crucial. To tackle inter-operator variability (IOV), peer review quality assurance (PRQA) has been increasingly implemented over the past decades and has become part of standard clinical practice, through recommendations in multiple national and regional guidelines. In the context of the ongoing peer review ProCaLung (PROject on the CAncer of the LUNG) initiative in Belgium, an assessment of current peer review practice in radiation oncology is proposed here. The main aims are to identify the frequency of changes, which aspects of treatment planning they occur in and what clinical impact good PRQA has. Additionally, current target delineation guidelines are reviewed to evaluate their suitability for standardized nodal volume peer reviewing in locally advanced non-small-cell lung cancer (NSCLC). Methods: A review of the published English literature was performed using the PubMed and Google Scholar databases within a specified timeframe (January 1, 2010–March 15, 2022). Publications must report the impact of peer review of one or multiple aspects of radiation oncology treatment planning. Current guidelines on peer review practice and treatment planning were obtained from the websites of respective societies. Key Content and Findings: Rates of changes recommended during peer review vary between 3.3% and 26%, with major changes occurring in 0.7% to 8.6% of cases. Changes occur across all elements of treatment planning, but those in target volume delineation (TVD) are most prevalent. No direct evidence proves the enhancement of clinical outcomes after peer review in routine practice. However, good quality control leads to better clinical outcomes in clinical trials, which could indicate that peer review is beneficial. The ESTRO-ACROP (The European Society for Radiation Oncology, The Advisory Committee for Radiation Oncology Practice) guidelines on target volume definition and de, SCOPUS: re.j, info:eu-repo/semantics/published

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. In this paper, we propose a method for how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecondrange magnetic-field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared with that in single ferromagnetic particles. Finally, we show how the excitation of spin waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20171122

We demonstrate that strongly-bound spin-vortex pairs exhibit pronounced stochastic behaviour. Such dynamics is due to collective magnetization states originating from purely dipolar interactions between the vortices. The resulting thermal noise exhibits telegraph-like behaviour, with random switching between different oscillation regimes observable at room temperature. The noise in the system is further studied by varying the external field and observing the related changes in the frequency of switching and the probability for different magnetic states and regimes. Monte Carlo simulations are used to replicate and explain the experimental observations., QC 20170206

Stacked spin-vortex pairs in magnetic multilayered nanopillars, with vertical separation between the vortices small compared to the vortex core size and pure magnetostatic coupling, exhibit spin dynamics absent in individual vortices. This dynamics is nonlinear and is due to the strong direct core-core coupling in the system, dominating energetically for small-signal excitation. We observe and explain the appearance of spin resonance modes, forbidden within linear dynamics, and discuss how they depend on the magnetic and morphological asymmetries in the samples., QC 20160520

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. Here we propose how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecond-range magnetic field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared to that in single ferromagnetic particles. Finally, we show how excitation of spin-waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20160524

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. Here we propose how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecond-range magnetic field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared to that in single ferromagnetic particles. Finally, we show how excitation of spin-waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20160524

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. Here we propose how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecond-range magnetic field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared to that in single ferromagnetic particles. Finally, we show how excitation of spin-waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20160524

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. Here we propose how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecond-range magnetic field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared to that in single ferromagnetic particles. Finally, we show how excitation of spin-waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20160524

Applications of magnetic memory devices greatly benefit from ultra-fast, low-power switching. Here we propose how this can be achieved efficiently in a nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane picosecond-range magnetic field pulses. Our detailed micromagnetic simulations, supported by analytical results, yield the parameter space where inertial switching and relaxation-free switching can be achieved in the system. We furthermore discuss the advantages of dynamic switching in synthetic antiferromagnets and, specifically, their relatively low-power switching as compared to that in single ferromagnetic particles. Finally, we show how excitation of spin-waves in the system can be used to significantly reduce the post-switching spin oscillations for practical device geometries., QC 20160524