D-shape Si3N4 waveguides are fabricated by dielectric lift-off process. We measure ultra-low loss for a 90nm-thick core of 2.42 dB/m at 1550 nm and a loaded Q-factor of 1.12x10(6) for a 0.8 mm radius resonator. (C) 20...
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ISBN:
(数字)9781943580767
ISBN:
(纸本)9781943580767
D-shape Si3N4 waveguides are fabricated by dielectric lift-off process. We measure ultra-low loss for a 90nm-thick core of 2.42 dB/m at 1550 nm and a loaded Q-factor of 1.12x10(6) for a 0.8 mm radius resonator. (C) 2020 The Author(s)
We observe stimulated Brillouin scattering (SBS) in AlGaAs-on-insulator integrated waveguides. A guided transverse acoustic mode has a 12.3 GHz Brillouin shift, and a full-width half-maximum of 25 MHz. (C) 2020 The Au...
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ISBN:
(数字)9781943580767
ISBN:
(纸本)9781943580767
We observe stimulated Brillouin scattering (SBS) in AlGaAs-on-insulator integrated waveguides. A guided transverse acoustic mode has a 12.3 GHz Brillouin shift, and a full-width half-maximum of 25 MHz. (C) 2020 The Author(s)
The main objectives of this dissertation include: (I) low-frequency homogenization of the wave equation in Rd with non-uniformly oscillating coefficients, (II) low-frequency solution of boundary value problem for 1D q...
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The main objectives of this dissertation include: (I) low-frequency homogenization of the wave equation in Rd with non-uniformly oscillating coefficients, (II) low-frequency solution of boundary value problem for 1D quasi-periodic waveguides, (III) solution of boundary value problem for 1D purely periodic waveguides at arbitrary frequency, as described below. Effective field equation. The focus of this work is dispersive, second-order effective model describing the low-frequency wave motion in heterogeneous (e.g. functionally- graded) media endowed with periodic microstructure. For this class of quasi-periodic medium variations, homogenization of the scalar wave equation in Rd, d ≥ 1 is pursued within the framework of multiple scales expansion. When either d = 1 or d = 2, this model problem bears direct relevance to the description of (anti-plane) shear waves in elastic solids. By adopting the lengthscale of microscopic medium fluctuations as the perturbation parameter, the germane low-frequency behavior is synthesized via a fourth- order differential equation (with smoothly varying coefficients) governing the mean wave motion in the medium, where the effect of microscopic heterogeneities is upscaled by way of the so-called cell functions. Effective boundary value problem. In an effort to demonstrate the relevance of the proposed analysis, presented in objective (I), toward solving boundary value problems (deemed to be the ultimate goal of most homogenization studies), effective boundary conditions are also developed, up to the second order of asymptotic approximation, applicable to one-dimensional (1D) shear wave motion in a macroscopically heterogeneous solid with periodic microstructure. The analysis is illustrated numerically in 1D by considering (i) low-frequency wave dispersion, (ii) mean-field homogenized description of the shear waves propagating in a finite domain, and (iii) full-field homogenized description thereof. In contrast to (i) where the overall wa
We consider the problem of imaging extended reflectors in three-dimensional acoustic waveguides using a planar array that is parallel to the waveguide's cross-section. Our data consist of the multiple-frequency ar...
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We consider the problem of imaging extended reflectors in three-dimensional acoustic waveguides using a planar array that is parallel to the waveguide's cross-section. Our data consist of the multiple-frequency array response matrix. To form an image, we back-propagate a projection of the data on the propagating modes in the waveguide. The projection operator is adequately defined for any array-aperture size and shape that cover fully or partially the waveguide cross-section. The properties of the imaging method are analyzed theoretically and its effectiveness is assessed by numerical experiments for scatterers and arrays of varying shape and size.
In waveguide theory calculating the energy flowing through the guide is often of prime interest and especially within elastodynamics the energy partition between the different transmission paths such as axial, torsion...
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The localized manipulation of acoustic fields in microfluidics is critical for the realization of high-performance operation in many biomedical applications. Herein, we demonstrate that our acoustofluidic waveguide (A...
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This work reports progress toward increased field of view from multi-order leaky mode devices. Specifically, we move from our previously published simulation toward physical instantiation including a glass-based test ...
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We investigate the dispersion of hybrid silicon-organic augmented low index guiding (ALIG) waveguides over a large spectral region. The GVD of the quasi-TM mode can be adjusted within either normal or anomalous regime...
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Mode hybridization in multimode waveguides is useful for polarization rotations and mode conversions. The effects of angled side walls on mode hybridization widths are numerically investigated in Z-cut and X-cut multi...
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We use two chip-scale waveguide platforms for self-referenced carrier-envelope offset frequency detection of a 10-GHz modelocked laser. A tunable beat note with a 33-dB signal-to-noise ratio is generated with only 18-...
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