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Vertical-cavity surface-emitting lasers (VCSELs) are valued for their high coupling efficiency, directionality, and low cost. Broad-area (BA)-VCSEL, in particular, offers the possibility of a customizable degree of spatial coherence and high output power for low-speckle imaging, illumination, communication, and augmented reality technologies. However, new designs of BA-VCSEL for scalable fabrication need to be developed. In this study, we present an annular cavity method for engineering optical characteristics and spatial coherence of VCSELs by altering the transverse shape of their cavities. Our experimental and simulation results reveal that annular VCSELs, with a doughnut shape, exhibit higher optical power density and lower threshold current due to more efficient utilization of gain medium compared to conventional BA-VCSELs. Notably, the annular VCSEL with a 20-µm radius central hole achieves a maximum optical power density of 1.09 kW/cm with a significant increase in external quantum efficiency (21.9%), outperforming the conventional BA-VCSEL (0.596 kW/cm and 16.1%). Spatial coherence analysis indicates that the designed annular VCSEL produces speckle patterns with lower intensity variations, enabling a higher number of mutually incoherent modes. The annular cavity design effectively achieves both low spatial coherence and Q-factor spoiling.
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http://dx.doi.org/10.1364/OE.545235 | DOI Listing |
Brain Topogr
September 2025
School of Biomedical Sciences, University of New South Wales (UNSW), Wallace Wurth Building, Kensington, NSW, 2052, Australia.
Different levels of reduced consciousness characterise human sleep stages at the behavioural level. On electroencephalography (EEG), the identification of sleep stages predominantly relies on localised oscillatory power within distinct frequency bands. Several theoretical frameworks converge on the central significance of long-range information sharing in maintaining consciousness, which experimentally manifests as high functional connectivity (FC) between distant brain regions.
View Article and Find Full Text PDFProc Int Conf Image Proc
September 2025
University of California, Irvine.
Spatial transcriptomics enables the study of gene expression within the spatial context of tissues, offering valuable insights into tissue organization and function. However, technical limitations can result in large missing regions of data, which hinder accurate downstream analyses and biological interpretation. To address these challenges, we propose (ffusion model for patial transcriptomics data mpletion), a framework with three key features.
View Article and Find Full Text PDFFoundation models have recently emerged as powerful feature extractors in computational pathology, yet they typically omit mechanisms for leveraging the global spatial structure of tissues and the local contextual relationships among diagnostically relevant regions - key elements for understanding the tumor microenvironment. Multiple instance learning (MIL) remains an essential next step following foundation model, designing a framework to aggregate patch-level features into slide-level predictions. We present EAGLE-Net, a structure-preserving, attention-guided MIL architecture designed to augment prediction and interpretability.
View Article and Find Full Text PDFACS Nano
September 2025
School of Physics and Astronomy, Monash University, Clayton, VIC 3800, Australia.
Strong electron-hole interactions in a semimetal or narrow-gap semiconductor may drive a ground state of condensed excitons. Monolayer WTe has been proposed as a host material for such an exciton condensate, but the order parameter─the key signature of a macroscopic quantum-coherent condensate─has not been observed. Here, we use Fourier-transform scanning tunneling spectroscopy (FT-STS) to study quasiparticle interference (QPI) and periodic modulations of the local density of states (LDOS) in monolayer WTe.
View Article and Find Full Text PDFTransl Vis Sci Technol
September 2025
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China.
Purpose: To investigate the spatial relationship between choroidal vortex veins (VVs), choroidal watershed zones (CWZs), and polypoidal lesion distribution in different subtypes of polypoidal choroidal vasculopathy (PCV) categorized by choroidal vascular hyperpermeability (CVH) status.
Methods: This retrospective study analyzed 58 treatment-naïve PCV eyes using widefield imaging to map dominant VVs, CWZs, and lesion locations. Eyes were stratified into CVH (n = 32) and non-CVH (n = 26) groups.