RESUMEN
Recent advances in silicon photonic components operating in the thulium-doped fiber amplifier (TDFA) wavelength regime around 2-µm have shown that these wavelengths hold great promise for on-chip photonic systems. Here we present our work on characterizing a Mach-Zehnder interferometer coupled silicon photonic ring resonator operating in the TDFA window for optical time delay applications. We describe the optical transmission and variable time delay properties of the resonator, including a detailed characterization and comparison of the directional coupler and Mach-Zehnder interferometer base components at both 1930 and 1550 nm wavelengths. The results show tuning of a ring from a 190-ps peak time delay at a resonant extinction ratio of 5.1-dB to a 560-ps peak time delay at an extinction ratio of 11.0-dB, in good agreement with optical models of the device. These results demonstrate significant promise towards the future application of TDFA band devices in optical time delay systems.
RESUMEN
PURPOSE/OBJECTIVE: The goals of the present study were (a) to document the prevalence of anxiety-related disorders and anxiety symptoms at 4, 8, and 12 months postinjury in individuals with mild traumatic brain injury (mTBI) while considering preinjury history of anxiety disorders and (b) to verify whether the presence of anxiety in the first months after mTBI was associated with more symptoms present 1 year after the injury. Research Method/Design: One hundred and twenty participants hospitalized after an accident and having sustained mTBI were assessed at 4, 8, and 12 months postaccident with the Mini-International Neuropsychiatric Interview, the Hospital Anxiety and Depression Scale, and questionnaires assessing fatigue, irritability, perceived stress, cognitive difficulties, depression, insomnia, and pain. RESULTS: At 4 months, 23.8% of participants presented with at least one anxiety-related disorder compared with 15.2% at 8 months and 11.2% at 12 months. Overall, 32.5% presented with at least one anxiety disorder over the first 12 months post-mTBI. Participants with a history of anxiety (20.5%) were significantly more anxious after their accident. Individuals who were anxious 4 months after the accident presented with more symptoms in different areas 12 months postinjury compared with nonanxious individuals. CONCLUSIONS/IMPLICATIONS: The present results highlight that anxiety should be evaluated and managed carefully as it appears to be a key factor in the persistence of other mTBI-related symptoms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
