In this paper, we present dispersion engineering in vertically coupled III-nitride (GaN/AlN/GaN) waveguides for short (blue) wavelengths. Peak anomalous dispersion approximate to 1:83 x 10(5) ps/nm - km is achieved by...
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ISBN:
(纸本)9781943580910
In this paper, we present dispersion engineering in vertically coupled III-nitride (GaN/AlN/GaN) waveguides for short (blue) wavelengths. Peak anomalous dispersion approximate to 1:83 x 10(5) ps/nm - km is achieved by tuning the geometric parameters and thereby coupling strength of the waveguides. (c) 2021TheAuthor(s)
Chip-integrated waveguides for gas sensing have inadequate evanescent field interaction. A thin-film mesoporous waveguide has enhanced sensitivity through gas interaction with the field inside the waveguide-core, demo...
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ISBN:
(纸本)9781665418768
Chip-integrated waveguides for gas sensing have inadequate evanescent field interaction. A thin-film mesoporous waveguide has enhanced sensitivity through gas interaction with the field inside the waveguide-core, demonstrated through spectroscopic detection of acetylene at 1520 nm.
Group III-V materials on sapphire substrate opens a new avenue for photonics integrated circuits. GaAs/AlGaAs straight waveguides on sapphire substrate were numerically studied. The propagation loss, single-mode, and ...
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ISBN:
(纸本)9781957171258
Group III-V materials on sapphire substrate opens a new avenue for photonics integrated circuits. GaAs/AlGaAs straight waveguides on sapphire substrate were numerically studied. The propagation loss, single-mode, and multi-mode operation conditions were reported.
In this work we investigate optical properties of a new type of micro structured waveguide called helical Bragg waveguide. The resonant coupling between OAM modes of the waveguide has been studied theoretically and ex...
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ISBN:
(纸本)9781665418768
In this work we investigate optical properties of a new type of micro structured waveguide called helical Bragg waveguide. The resonant coupling between OAM modes of the waveguide has been studied theoretically and experimentally.
The process of writing Silicon waveguides using ultrashort lasers is investigated. After addressing the nonlinear propagation of the writing pulse analytically and numerically, we characterize the index profile of the...
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ISBN:
(纸本)9781665418768
The process of writing Silicon waveguides using ultrashort lasers is investigated. After addressing the nonlinear propagation of the writing pulse analytically and numerically, we characterize the index profile of the written waveguides using transversally-shifted inputs.
We analytically derived an explicit condition for high-contrast plasmonic modulation and switchable routing in coupled graphene waveguides consisting of two coupled gated graphene sheets sandwiching a gyrotropic mediu...
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We analytically derived an explicit condition for high-contrast plasmonic modulation and switchable routing in coupled graphene waveguides consisting of two coupled gated graphene sheets sandwiching a gyrotropic medium. The analytical condition intuitively predicts that by manipulating the graphene chemical potential and the gyration of the in-between medium we can combine robustness of the plasmonic routing to the deviation of design and material parameters due to imperfect fabrication and harsh environment with the extreme high contrast. Also, it predicts broadband tunability of the high-contrast plasmonic routing. The intuitive analytical condition reveals that the high contrast is achievable at a resonance gyration due to a magnetic resonance of nonreciprocal directional coupling. The magnetic resonance of nonreciprocity breaks a currently held preconception that the stronger magnetic field induces the stronger magnetically induced nonreciprocity. Numerical simulations demonstrate the robustness of the magnetic resonance of nonreciprocity and its tunability over a one-octave spanning spectral range. In practice, the chemical potential and the gyration can be manipulated by controlling the gate voltage of the graphene and the external magnetic field, respectively. Our findings would provide a robust and broadband tunable tool for high-contrast plasmonic modulator and switchable router and for probing of ultrafast magnetization dynamics.
We present a comprehensive study surface plasmon polariton (SPP) propagation on planar metallic waveguides under a dressing field. We perform a set of analytical calculations of the periodic time-dependent Schröd...
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We present a comprehensive study surface plasmon polariton (SPP) propagation on planar metallic waveguides under a dressing field. We perform a set of analytical calculations of the periodic time-dependent Schrödinger equation to study the interaction of an intense electromagnetic field with a metallic system. We model the strong light coupling to the metallic system using a nonperturbative procedure. In this paper, we show that, by introducing Floquet theory into the dressed metal, the behavior of the Floquet states are similar to the phase-modulated signals in the communication system. This will reveal a new perspective on the underlying science in an intricate, dressed quantum system. Furthermore, we examine the impurity scattering effects on charge transport in disordered plasmonic metals using the generalized Floquet-Fermi golden rule and provide a novel approach to diminish the losses in plasmonic materials using the dressing field. To gauge the effectiveness of our results, we introduce a figure of merit to compare the performance of plasmonic metals, subjective to a dressing field. The calculated dressed SPP characteristics suggest that high-efficiency SPP propagation can be achieved in practice. Our findings open up new directions for state-of-the-art nanoplasmonic devices.
Guidance of classical waves is key to many technologies, but high-efficiency, omnidirectional performance is difficult to achieve. Here, an ultrathin, broadband elastic metagrating is proposed for suppression of paras...
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Guidance of classical waves is key to many technologies, but high-efficiency, omnidirectional performance is difficult to achieve. Here, an ultrathin, broadband elastic metagrating is proposed for suppression of parasitic diffraction and guiding waves along an arbitrary path. Guiding classical waves has inspired a wealth of nontrivial physics and significant applications. To date, a robust and compact way to guide energy flux traveling along an arbitrary, prescheduled trajectory in a uniform medium is still a fundamental challenge. Here we propose and experimentally realize a generic framework of ultrathin waveguides for omnidirectional wave trapping and efficient routing. The metagrating-based waveguide can totally suppress all high-order parasitic diffractions to route guided elastic waves without leakage. The proposed waveguide protype works in a broad frequency range under a full-angle radiated source. An analytical slab-waveguide model is presented to predict and tailor the diffracted patterns. Compared with existing methods based on topological edge states or defected metamaterials, our meta-waveguide strategy exhibits absolute advantages in compact size, robust performance, and easy fabrication, which may provide a design paradigm for vibration and noise control, energy harvesting, microfluidics, wave steering in acoustics and other waves.
Optical waveguides usually exploit modulation of the dynamic phase, i.e., transverse gradient in the refractive index, to guide light. Recently, a novel type of optical waveguides based upon the Pancharatnam-Berry pha...
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ISBN:
(纸本)9798350345995
Optical waveguides usually exploit modulation of the dynamic phase, i.e., transverse gradient in the refractive index, to guide light. Recently, a novel type of optical waveguides based upon the Pancharatnam-Berry phase (PBP) has been introduced [1]. The PBP is a type of geometric phase which is determined by the path traced by the polarization on the Poincaré sphere. For example, PBP gained by a circularly polarized (CP) beam after crossing a half-wave plate (HWP) is twice the rotation angle of the crystal, the sign being dictated by the photon helicity [2]. Hence, an inhomogeneous rotation in the transverse plane induces a transverse phase gradient. However, the PBP does not accumulate in propagation if the structure is uniform along the longitudinal (propagation) direction. A net accumulation, and thus localization, is achieved when the anisotropic material is periodically perturbed along the propagation direction. The optimum is indeed attained when the longitudinal modulation is synchronized with the natural rotation of the polarization [1], [3].
It is estimated that 5%–14% of cancer patients will develop symptomatic metastatic epidural spinal cord compression (ie, spinal metastasis) during the course of their disease, which can lead to devastating complicati...
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