Beam-steering devices such as optical phased arrays (OPAs) are key components in the applications of solid-state Lidar and wireless communication. The traditional single-layer OPA results in a significant energy loss due to substrate leakage caused by the downward coupling from the grating coupler structure. In this work, we have investigated a structure based on a multi-layer ${\rm Si}_{3}{\rm N}_{4}/{\rm SiO}_{2}$SiN/SiO platform that can form a 3D OPA to emit light from the edge of the device with high efficiency; a 2D converged out-coupling beam will be end-fired to the air. High efficiency and wide horizontal beam steering are demonstrated numerically, and the influence of vertical crosstalk, delay length, and number of waveguide layers are discussed, as well as the fabrication feasibility.
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http://dx.doi.org/10.1364/AO.382962 | DOI Listing |
J Am Soc Mass Spectrom
January 2025
Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.
Phased structures for lossless ion manipulation offer significant improvements over the scanning second gate method for coupling with ion trap mass analyzers. With an experimental run time of under 1 min for select conditions and an average run time of less than 4 min, this approach significantly reduces experimental time while enhancing the temporal duty cycle. The outlined SLIM system connects to an ion trap mass analyzer via a PCB stacked ring ion guide, which replaces the commercial ion optics and capillary inlet.
View Article and Find Full Text PDFUltrasonics
December 2024
School of Mechatronic & Automation Engineering, Shanghai University, Shanghai 200444, China; Key Laboratory of Silicate Cultural Relics Conservation (Shanghai University), Ministry of Education, China. Electronic address:
Fiber reinforced polymer composites (FRPs) are essential for various industrial fields, but wrinkles inside will greatly reduce their mechanical properties. Full-matrix capture (FMC) is a popular data structure for ultrasonic phased array imaging in composites. However, such structure may lead to data redundancy and noise interference.
View Article and Find Full Text PDFJCI Insight
December 2024
Department of Ophthalmology and Roger and Karalis Johnson Retina Center, University of Washington, Seattle, United States of America.
Background: Current clinical sequencing methods cannot effectively detect DNA methylation and allele-specific variation to provide parent-of-origin information from the proband alone. Parent-of-origin effects can lead to differential disease and the inability to assign this in de novo cases limits prognostication in the majority of affected individuals with retinoblastoma, a hereditary cancer with suspected parent-of-origin effects.
Methods: To directly assign parent-of-origin in retinoblastoma patients, genomic DNA was extracted from blood samples for sequencing using a programmable, targeted single-molecule long-read DNA genomic and epigenomic approach.
Heliyon
December 2024
Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh.
Bhasan Char has undergone noteworthy transformations in its geographical characteristics since its emergence in 2003. Driven by sediment transported by the Ganges-Brahmaputra-Meghna river system, the island has gradually transitioned from a stretched-out configuration to a more rounded shape primarily due to continuous accretion, while erosion has been minimal since 2012. Currently, the island is being prepared to accommodate over 1 million Forcefully Displaced Myanmar Nationals (FDMN) refugees.
View Article and Find Full Text PDFIn brain activity mapping with optogenetics, patterned illumination is crucial for targeted neural stimulation. However, due to optical scattering in brain tissue, light-emitting implants are needed to bring patterned illumination to deep brain regions. A promising solution is silicon neural probes with integrated nanophotonic circuits that form tailored beam patterns without lenses.
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