Engineering and detection of light scattering directionalities in dewetted nanoresonators through dark-field scanning microscopy.

Dewetted, SiGe nanoparticles have been successfully exploited for light management in the visible and near-infrared, although their scattering properties have been so far only qualitatively studied. Here, we demonstrate that the Mie resonances sustained by a SiGe-based nanoantenna under tilted illumination, can generate radiation patterns in different directions. We introduce a novel dark-field microscopy setup that exploits the movement of the nanoantenna under the objective lens to spectrally isolate Mie resonances contribution to the total scattering cross-section during the same measurement. The knowledge of islands' aspect ratio is then benchmarked by 3D, anisotropic phase-field simulations and contributes to a correct interpretation of the experimental data.

Tailoring Third-Harmonic Diffraction Efficiency by Hybrid Modes in High-Q Metasurfaces.

Metasurfaces are versatile tools for manipulating light; however, they have received little attention as devices for the efficient control of nonlinearly diffracted light. Here, we demonstrate nonlinear wavefront control through third-harmonic generation (THG) beaming into diffraction orders with efficiency tuned by excitation of hybrid Mie-quasi-bound states in the continuum (BIC) modes in a silicon metasurface. Simultaneous excitation of the high-Q collective Mie-type modes and quasi-BIC modes leads to their hybridization and results in a local electric field redistribution. We probe the hybrid mode by measuring far-field patterns of THG and observe the strong switching between (0,-1) and (-1,0) THG diffraction orders from 1:6 for off-resonant excitation to 129:1 for the hybrid mode excitation, showing tremendous contrast in controlling the nonlinear diffraction patterns. Our results pave the way to the realization of metasurfaces for novel light sources, telecommunications, and quantum photonics.

Third-harmonic light polarization control in magnetically resonant silicon metasurfaces.

Nonlinear metasurfaces have become prominent tools for controlling and engineering light at the nanoscale. Usually, the polarization of the total generated third harmonic is studied. However, diffraction orders may present different polarizations. Here, we design an high quality factor silicon metasurface for third harmonic generation and perform back focal plane imaging of the diffraction orders, which present a rich variety of polarization states. Our results demonstrate the possibility of tailoring the polarization of the generated nonlinear diffraction orders paving the way to a higher degree of wavefront control.

Engineering of the spin on dopant process on silicon on insulator substrate.

We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via spin-on-dopant process (SOD). This method is used to provide an impurity source for semiconductor junction fabrication. The dopant is first spread into the substrate via SOD and then diffused by a rapid thermal annealing process. The dopant concentration and electron mobility were characterized at room and low temperature by four-probe and Hall bar electrical measurements. Time-of-flight-secondary ion mass spectroscopy was performed to estimate the diffusion profile of phosphorus for different annealing treatments. We find that a high phosphorous concentration (greater than 1020 atoms cm-3) with a limited diffusion of other chemical species and allowing to tune the electrical properties via annealing at high temperature for short time. The ease of implementation of the process, the low cost of the technique, the possibility to dope selectively and the uniform doping manufactured with statistical process control show that the methodology applied is very promising as an alternative to the conventional doping methods for the implementation of optoelectronic devices.

Effects of combined ACE inhibitor and angiotensin II antagonist treatment in human chronic nephropathies.

BACKGROUND: Proteinuria predicts renal disease progression, and its reduction by angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor antagonists (ARA) is renoprotective. METHODS: In this prospective, randomized, cross-over study of 24 patients with nondiabetic, chronic nephropathies, we compared the effects on proteinuria, renal hemodynamics, and glomerular permselectivity of 8 weeks with comparable blood pressure control achieved by benazepril (10 mg/day) and valsartan (80 mg/day) combined therapy with those achieved by benazepril (20 mg/day) or valsartan (160 mg/day) alone. RESULTS: Despite comparable changes in blood pressure and glomerular filtration rate (GFR), combined therapy decreased proteinuria more than benazepril (-56% vs. -45.9%, P=0.02) and valsartan (-41.5%, P=0.002). Changes in urinary protein to creatinine ratio followed the same trend. Filtration fraction and renal vascular resistances (RVR) decreased more with combined (-14.7%,-23.7%) or benazepril (-12.4%, -20.5%) than with valsartan (-2.7%, -12.5%, P < 0.05 vs. both). RVR changes, adjusted for GFR changes, were associated with those in proteinuria (P < 0.05). Changes in glomerular permeability were comparable and did not predict different changes in proteinuria in the three groups. CONCLUSION: At comparable blood pressure, combined ACEi and ARA decreased proteinuria better than ACEi and ARA. The greater antiproteinuric effect most likely depended on an ACEi-related hemodynamic effect, in addition to glomerular size selectivity amelioration. Long-term combined ACEi and ARA therapy may be more renoprotective than treatment with each agent alone.