We simulate the optical properties of polymer optical waveguides with different refractive index profiles in their cores as coupling components (edge couplers) between single-mode fiber and SiOx waveguides. In this paper, we focus on the single-mode operation of graded-index (GI) core polymer waveguides, for which we previously demonstrated low propagation loss under multimode operation. We design the optimum core structure (size and index contrast) for different refractive index profiles, and then demonstrate the unique optical properties of GI waveguides contributing to the low optical loss compared to the step-index counterparts, in particular, mode field diameter variation and taper angle tolerance.
View Article and Find Full Text PDFThe red panda (Ailurus fulgens) can be found in zoos around the world, and various behavioral restraint procedures are used as part of their health care. Wild animals that are kept in zoos, including red pandas, are known to have a longer life span than those in the wild. Therefore, the health management of aging animals is considered especially important for zoos that maintain many precious wild animals.
View Article and Find Full Text PDFStudy Objectives: Obstructive sleep apnea (OSA) can induce excessive sleepiness, causing work-related injuries and low productivity. Most individuals with OSA in the United Kingdom are undiagnosed, and thus, theoretically, workplace screening, might by identifying these individuals improve both their individual health and overall productivity. However, the prevalence of OSA in different workplaces is unclear.
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