Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"directional coupler"”.
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Methods for compact modeling of process variations in silicon photonics devices
… models are generated using these methods for the directional coupler and the Y-branch, two passive devices widely used in silicon photonics. The use of these models is demonstrated through corner and statistical variation analyses of a simple Mach-Zehnder interferometer photonic circuit composed …
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Human identification through wearable antenna characteristics
… wearable network is designed with a novel directional coupler to investigate properties of the human body through antenna characteristics. Machine learning techniques are applied to generate a biometric from antenna characteristics and identify a human through antenna-body interaction. This …
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Photonic Crystal Lorentz Force Magnetometer for Out-of-Plane Magnetic Field Sensing
… based on the concept of a photonic crystal directional coupler (PCDC) for magnetic field sensing perpendicular (out-of-plane) to the chip surface. Built on the Silicon-On-Insulator platform, a custom post-processing recipe was developed to fabricate the electrically controlled optomechanical …
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Adaptive Control of Waveguide Modes in Two-Mode Fibers
… are provided by all-fiber devices such as a directional fiber coupler or fiber Bragg gratings (FBGs). Using the coupling ratio of a directional coupler as feedback, we demonstrate adaptive control of LP modes at the two output ports of the directional coupler. With feedback determined by the …
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The split-cavity cross-coupled extrinsic fiber interferometer
… utilizes two EFPI sensor heads on a single directional coupler in a Split-cavity Cross-coupled Extrinsic Fiber Interferometer (SCEFI) arrangement. This sensor configuration eliminates the need for biasing the phase difference at the quadrature point. The spectrum analysis scheme, devised for …
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Coupled-waveguide Fabry-Perot resonator
… the attributes of both Fabry-Perot resonator and directional coupler. The coupled-mode theory of parallel waveguides is employed to analyze the proposed structure. Spectral characteristics are derived from the governing coupled-mode equations and related boundary conditions. Two geometries …
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Optical signal generation, stabilization, and manipulation in broadband silicon photonics
… with the sharpest roll-offs to date. Finally, directional coupler based solutions are studied to address wavelength selectivity for octave-wide signals, and propose designs for ultra-wideband couplers.
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Femtosecond laser fabrication of directional couplers and Mach-Zehnder interferometers
… index in glass, a variety of devices such as couplers, interferometers, gratings, 3D structures, active waveguides, and void structures have been successfully demonstrated. In contrast to conventional semiconductor-based fabrication processes, the femtosecond laser fabrication process utilizes …
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Single-band and Dual-band Beam Switching Systems and Offset-fed Beam Scanning Reflectarray
… the stacked patch antennas and a slotcoupled directional coupler is used for the circularly polarized operation. The research presented in this dissertation suggests useful techniques for a beam scanning microstrip reflectarray, phased array antenna, and wideband antenna designs in the modern …
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Chip-based photonic sensors for metrology and applications
… Mach-Zehnder interferometer, photonic crystal, directional coupler, grating, etc. In this thesis we focus on two types of photonic sensors, micro-ring resonator and high contrast grating membrane, including their fabrication, theoretical basis, experimental characterizations, and their …
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Reconfigurable Photonics based on Broadband Low-loss Optical Phase Change Materials
… for scalable photonic networks. A transient directional coupler is proposed and realized to facilitate wafer-scale photonic testing. Material cycling lifetime is also investigated by tracking the reflectance contrast between the amorphous and crystalline state on a single pixel over 1,000 …
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Advanced light manipulation and waveguiding in plasmonic nanostructured optical fibers.
… lengths, polarization splitters, and optical directional coupler (ODC) onto the optical fiber. This project first proof-of-concept demonstration on developing an ultra-compact plasmonic network on the tip of optical fiber for advanced optical communications applications. The final project …
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Nonlinear Photonics in Waveguides for Telecommunications
… as the active material. The design uses a simple directional coupler with coplanar electrodes and promises to have low cross-talk and high switching speed (on the order of nanoseconds). An initial design for a 1x2 switch is fabricated and tested, and future optimization processes are also …
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Optimization of silicon photonic devices for polarization diversity applications
… method, the power transfer from the input to the coupler section and at the output ports can be evaluated. When designing polarization rotators, it is necessary to calculate the modal hybridness of a mode. In this research, it is identified that when the symmetric waveguides are broken, the modal …
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A Novel Long-Range Passive UHF RFID System over Twisted-pair Cable
… simultaneous, finite isolation of the circulator/directional coupler and environmentally dependent reflection ratio of the antenna lead to serious leakage problems. Leakage can directly cause sensitivity degradation due to saturation of the RF components. A fast leakage suppression block is …