Publications by authors named "T Hawkins"
Modern commercial erbium-doped fibers are limited in their doping concentrations due to the tendency of Er ions to cluster in silicate glasses. Clustering inevitably leads to ion quenching, one major obstacle preventing erbium-doped fibers (EDFs) from scaling to higher laser power near 15XX nm. Here, we present a new, to our knowledge, method for doping erbium into fibers through the use of Er:BaF nanoparticle (NP) precursors.
View Article and Find Full Text PDFArticle Synopsis
- Polycrystalline silicon-germanium (SiGe) core fibers have been developed as flexible platforms for advanced optoelectronic devices, showing promise for higher performance than traditional silicon fibers due to their enhanced nonlinear properties and adjustable composition.
- A specific type of SiGe core fiber was created using a molten core drawing method and improved with CO laser irradiation to ensure core uniformity, followed by a fiber tapering technique to optimize its transmission properties.
- The resulting SiGe fiber demonstrated low linear loss across a mid-infrared wavelength range and showed improved nonlinear performance, suggesting significant potential for future applications in nonlinear photonics, especially in the >2 µm wavelength region.
Article Synopsis
- - The Mercy Halo Ovarian Cancer Test (OC Test) is a new screening method that detects ovarian cancer by analyzing proteins found on tumor-associated extracellular vesicles in blood, aiming for both high sensitivity and specificity.
- - In a study involving 397 women, the OC Test showed impressive results: 97% specificity and sensitivity for high-grade serous carcinoma (HGSC), and it also identified 73.5% of non-HGSC ovarian cancer cases.
- - Compared to the conventional cancer antigen 125, the OC Test resulted in fewer false positives among patients with non-cancerous conditions, indicating its potential for effective ovarian cancer screening.
Nonisocyanate polyurethanes (NIPUs) show promise as more sustainable alternatives to conventional isocyanate-based polyurethanes (PUs). In this study, polyhydroxyurethane (PHU) and nonisocyanate polythiourethane (NIPTU) production and reprocessing models inform the results of a techno-economic analysis and a life cycle assessment. The profitability of selling PHU and NIPTU is rationalized by identifying significant production costs, indicating that raw materials drive the costs of PHU and NIPTU production and reprocessing.
View Article and Find Full Text PDFFor the first time, to our knowledge, an all-solid transverse Anderson localizing optical fiber laser is demonstrated. A combination of the molten core and stack-and-draw fiber fabrication techniques is used to produce a 112 µm core diameter fiber that is a random array of Yb-doped high index and passive low index regions. A localized channel first assists in the guidance of amplified spontaneous emission before stimulating laser action, which occurs in the same channel via mixed Anderson localization and step index wave-guiding.
View Article and Find Full Text PDF