Subwavelength Custom Wavefront Shaping by a Nonlinear Electro-optic Spatial Light Modulator

Holographic displays offer a method to completely reconstruct any desired wavefront and can thus lead to breakthrough innovation in beamforming, sensing, and information encryption. However, full control over a wavefront in the visible requires features of 100 nm or less. Here, we apply these stringent requirements in an all-encompassing device structure including light source, modulator, and driver electronics. To this end, we propose a continuous electro-optically modulated barium titanate slab waveguide employing a metamaterial cladding layer enabling electrodes to be in contact with the optically active layer. This prevents both the undesired scattering and the absorption that metallic electrodes would introduce. We elaborate the driving requirements of the proposed waveguide display including the optimal use of a nonlinear barium titanate crystal and electrical and optical simulations that show complete control over a waveguided mode, resulting in desired holographic imaging in far-field simulations

Non-linear electro-optic modelling of a Barium Titanate grating coupler

We provide insight into the driving mechanisms and requirements to create an electro-optic spatial light modulator based on a Barium Titanate waveguide and an optically transparent electrode cladding layer. We have developed a generic framework of electric field simulations and non-linear optics to create any desired modulation in an area of interest, applicable for liquid crystals, Pockels and Kerr cells. Targeting our device structure, we have evaluated several design parameters of the arbitrarily reprogrammable SLM, capable of optical beamforming and high-quality holograms.status: publishe

Exploiting Two-Step Processed Mixed 2D/3D Perovskites for Bright Green Light Emitting Diodes

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Mixed 2D/3D perovskite films with self-assembled quantum wells have significantly improved the performance of perovskite light emitting diodes (PeLEDs). In this work, such films are fabricated through a two-step interdiffusion method that is widely employed in processing of perovskite solar cells, however, remains rarely explored for PeLEDs. The effects of incorporating large-cation ligand, i.e., butylammonium bromide (BABr) into formamidinium lead bromide (FAPbBr 3 ) based perovskites, in terms of film composition, morphology, optoelectronic properties as well as device performance are thoroughly investigated in this method. By modulating BABr:PbBr 2 ratio in the precursor solution, the optimal device shows a maximum external quantum efficiency (EQE) of 7.36% at 147.7 mA cm −2 and a brightness of 37 720 Cd m −2 at 5 V. The performance is remarkably higher than a reference device without BABr that shows a maximum EQE of 2.53% and a brightness of 6190 Cd m −2 at 5 V. The versatility of this method is further extended to another large-cation ligand, 4-fluoro-benzylammonium bromide (F-BZABr), which leads to maximum EQE of 8.55%. This work indicates two-step processed mixed 2D/3D perovskites are promising for bright green PeLEDs.status: publishe

Reduced Efficiency Roll-Off and Improved Stability of Mixed 2D/3D Perovskite Light Emitting Diodes by Balancing Charge Injection

status: publishe

An exome-wide study of renal operational tolerance

BackgroundRenal operational tolerance is a rare and beneficial state of prolonged renal allograft function in the absence of immunosuppression. The underlying mechanisms are unknown. We hypothesized that tolerance might be driven by inherited protein coding genetic variants with large effect, at least in some patients.MethodsWe set up a European survey of over 218,000 renal transplant recipients and collected DNAs from 40 transplant recipients who maintained good allograft function without immunosuppression for at least 1 year. We performed an exome-wide association study comparing the distribution of moderate to high impact variants in 36 tolerant patients, selected for genetic homogeneity using principal component analysis, and 192 controls, using an optimal sequence-kernel association test adjusted for small samples.ResultsWe identified rare variants of HOMER2 (3/36, FDR 0.0387), IQCH (5/36, FDR 0.0362), and LCN2 (3/36, FDR 0.102) in 10 tolerant patients vs. 0 controls. One patient carried a variant in both HOMER2 and LCN2. Furthermore, the three genes showed an identical variant in two patients each. The three genes are expressed at the primary cilium, a key structure in immune responses.ConclusionRare protein coding variants are associated with operational tolerance in a sizable portion of patients. Our findings have important implications for a better understanding of immune tolerance in transplantation and other fields of medicine.ClinicalTrials.gov, identifier: NCT05124444

An exome-wide study of renal operational tolerance

Background Renal operational tolerance is a rare and beneficial state of prolonged renal allograft function in the absence of immunosuppression. The underlying mechanisms are unknown. We hypothesized that tolerance might be driven by inherited protein coding genetic variants with large effect, at least in some patients. Methods We set up a European survey of over 218,000 renal transplant recipients and collected DNAs from 40 transplant recipients who maintained good allograft function without immunosuppression for at least 1 year. We performed an exome-wide association study comparing the distribution of moderate to high impact variants in 36 tolerant patients, selected for genetic homogeneity using principal component analysis, and 192 controls, using an optimal sequence-kernel association test adjusted for small samples. Results We identified rare variants of HOMER2 (3/36, FDR 0.0387), IQCH (5/36, FDR 0.0362), and LCN2 (3/36, FDR 0.102) in 10 tolerant patients vs .0 controls. One patient carried a variant in both HOMER2 and LCN2 .Furthermore, the three genes showed an identical variant in two patients each. The three genes are expressed at the primary cilium, a key structure in immune responses. Conclusion Rare protein coding variants are associated with operational tolerance in a sizable portion of patients. Our findings have important implications for a better understanding of immune tolerance in transplantation and other fields of medicine. ClinicalTrials.gov ,identifier: NCT05124444.info:eu-repo/semantics/publishe

An exome-wide study of renal operational tolerance.

Renal operational tolerance is a rare and beneficial state of prolonged renal allograft function in the absence of immunosuppression. The underlying mechanisms are unknown. We hypothesized that tolerance might be driven by inherited protein coding genetic variants with large effect, at least in some patients. We set up a European survey of over 218,000 renal transplant recipients and collected DNAs from 40 transplant recipients who maintained good allograft function without immunosuppression for at least 1 year. We performed an exome-wide association study comparing the distribution of moderate to high impact variants in 36 tolerant patients, selected for genetic homogeneity using principal component analysis, and 192 controls, using an optimal sequence-kernel association test adjusted for small samples. We identified rare variants of (3/36, FDR 0.0387), (5/36, FDR 0.0362), and (3/36, FDR 0.102) in 10 tolerant patients . 0 controls. One patient carried a variant in both and . Furthermore, the three genes showed an identical variant in two patients each. The three genes are expressed at the primary cilium, a key structure in immune responses. Rare protein coding variants are associated with operational tolerance in a sizable portion of patients. Our findings have important implications for a better understanding of immune tolerance in transplantation and other fields of medicine.ClinicalTrials.gov, identifier: NCT05124444