A four-laser array based on sampled Bragg grating distributed feedback (DFB) lasers in which each sampled period contains four phase-shift sections is proposed, fabricated, and experimentally demonstrated. The wavelength spacing between adjacent lasers is accurately controlled to 0.8 nm ± 0.026 nm and the lasers have single mode suppression ratios larger than 50 dB. Using an integrated semiconductor optical amplifier, the output power can reach 33 mW and the optical linewidth of the DFB lasers can be as narrow as 64 kHz. This laser array uses a ridge waveguide with sidewall gratings and needs only one metalorganic vapor-phase epitaxy (MOVPE) step and one III-V material etching process, simplifying the whole device fabrication process, and meeting the requirements of dense wavelength division multiplexing systems.
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http://dx.doi.org/10.1364/OL.475909 | DOI Listing |
Nat Commun
January 2025
The Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, PR China.
Obstructive sleep apnea is a globally prevalent concern with significant health impacts, especially when coupled with comorbidities. Accurate detection and localization of airway obstructions are crucial for effective diagnosis and treatment, which remains a challenge for traditional sleep monitoring methods. Here, we report a catheter-based flexible pressure sensor array that continuously monitors soft tissue pressure in the upper airway and facilitates at the millimeter level.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Jieyang 515200, China.
Optical physical unclonable functions (PUFs) are gaining attention as a robust security solution for identification in the expanding Internet of Things (IoT). To enhance the security and functionality of PUFs, integrating multiple optical responses─such as fluorescence and structural color─into a single system is essential. These diverse optical properties enable multilevel authentication, where different layers of security can be verified under varying light conditions, greatly reducing the risk of counterfeiting.
View Article and Find Full Text PDFBr J Dermatol
December 2024
Department of Dermatology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Background: The tumour microenvironment significantly influences the clinical response of patients to therapeutic immune checkpoint inhibition (ICI), but a comprehensive understanding of the underlying immune-regulatory proteome is still lacking.
Objectives: To decipher targetable biologic processes that determine tumour-infiltrating lymphocytes (TiLs) as a cellular equivalent of clinical response to ICI.
Methods: We mapped the spatial distribution of proteins in TiL-enriched vs.
Nat Commun
December 2024
Department of Chemical Engineering, Electrochemical Innovation Lab, University College London, London, UK.
High-temperature proton exchange membrane fuel cells (HT-PEMFCs) offer solutions to challenges intrinsic to low-temperature PEMFCs, such as complex water management, fuel inflexibility, and thermal integration. However, they are hindered by phosphoric acid (PA) leaching and catalyst migration, which destabilize the critical three-phase interface within the membrane electrode assembly (MEA). This study presents an innovative approach to enhance HT-PEMFC performance through membrane modification using picosecond laser scribing, which optimises the three-phase interface by forming a graphene-like structure that mitigates PA leaching.
View Article and Find Full Text PDFNat Commun
December 2024
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we develop a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma.
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