We report continuous-wave (CW) blue semipolar (202¯1) III-nitride laser diodes (LDs) that incorporate limited area epitaxy (LAE) n-AlGaN bottom cladding with thin p-GaN and ZnO top cladding layers. LAE mitigates LD design limitations that arise from stress relaxation, while ZnO layers reduce epitaxial growth time and temperature. Numerical modeling indicates that ZnO reduces the internal loss and increases the differential efficiency of TCO clad LDs. Room temperature CW lasing was achieved at 445 nm for a ridge waveguide LD with a threshold current density of 10.4 kA/cm, a threshold voltage of 5.8 V, and a differential resistance of 1.1 Ω.
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http://dx.doi.org/10.1364/OE.26.012490 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Earth Sciences, Montana State University, Bozeman, MT 59717.
Climate-driven changes in high-elevation forest distribution and reductions in snow and ice cover have major implications for ecosystems and global water security. In the Greater Yellowstone Ecosystem of the Rocky Mountains (United States), recent melting of a high-elevation (3,091 m asl) ice patch exposed a mature stand of whitebark pine () trees, located ~180 m in elevation above modern treeline, that date to the mid-Holocene (c. 5,950 to 5,440 cal y BP).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045.
Climate change is increasing the frequency of large-scale, extreme environmental events and flattening environmental gradients. Whether such changes will cause spatially synchronous, large-scale population declines depends on mechanisms that limit metapopulation synchrony, thereby promoting rescue effects and stability. Using long-term data and empirical dynamic models, we quantified spatial heterogeneity in density dependence, spatial heterogeneity in environmental responses, and environmental gradients to assess their role in inhibiting synchrony across 36 marine fish and invertebrate species.
View Article and Find Full Text PDFJMIR Res Protoc
January 2025
College of Medicine and Public Health, Flinders University, Bedford Park, Australia.
Background: There is limited evidence of high-quality, accessible, culturally safe, and effective digital health interventions for Indigenous mothers and babies. Like any other intervention, the feasibility and efficacy of digital health interventions depend on how well they are co-designed with Indigenous communities and their adaptability to intracultural diversity.
Objective: This study aims to adapt an existing co-designed mobile health (mHealth) intervention app with health professionals and Aboriginal and/or Torres Strait Islander mothers living in South Australia.
Otol Neurotol
February 2025
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD.
Objective: The physician-scientist workforce is shrinking in the United States. Academic otologists/neurotologists face a diverse set of barriers to successful careers. We aimed to characterize the factors affecting contemporary otology/neurotology surgeon-scientists.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Geography and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa.
Successful innovation requires employees to have intellectual and technical capacity. This study explored the effects of capacity building through educational learning, organizational training, and coaching on agricultural innovation. A sample of 142 operational-level agriculture scientists working within a public sector agricultural research organisation in Zimbabwe.
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