PR_27 Imaging Band-edge Localization in a Silicon Coupled Microring Waveguide (0925133-PO)

The band-edge localization of light in a coupled resonator optical waveguide (CROW) consisting of silicon microring resonators is studied theoretically and experimentally. Summary of a Project Outcomes report of research funded by the National Science Foundation under Project Number 0925133.

Static Metasurface Reflectors with Independent Magnitude and Phase Control using Coupled Resonator Configuration

<div>A static metasurface reflector based on a novel coupled resonator configuration is proposed to independently control</div><div>the reflection phase and magnitude of linearly polarized incident fields, and is demonstrated experimentally in the millimeter-wave Ka-band around 30 GHz. The proposed concept is illustrated using a unit cell design consisting of a rectangular ring coupled with a rectangular slot resonator backed by a grounded dielectric slab. By geometrically tuning various dimensions of the two resonators, a near-perfect amplitude-phase coverage is achieved at a fixed design frequency of 30 GHz. To demonstrate the flexible beam-forming capability of the proposed metasurface reflectors, illustrative examples of fixed beam steering with varying reflection magnitudes, and asymmetric dual-beam patterns with specified reflection magnitude, reflection angles and beam-widths, are successfully shown. Compared to the standard method based on polarization rotation and resistive loadings with discrete values, the proposed technique does not generate undesired cross-polarization field reflection, and provides a continuous magnitude tuning including full absorption, along with wide phase coverage.</div>

Static Metasurface Reflectors with Independent Magnitude and Phase Control using Coupled Resonator Configuration

<div>A static metasurface reflector based on a novel coupled resonator configuration is proposed to independently control</div><div>the reflection phase and magnitude of linearly polarized incident fields, and is demonstrated experimentally in the millimeter-wave Ka-band around 30 GHz. The proposed concept is illustrated using a unit cell design consisting of a rectangular ring coupled with a rectangular slot resonator backed by a grounded dielectric slab. By geometrically tuning various dimensions of the two resonators, a near-perfect amplitude-phase coverage is achieved at a fixed design frequency of 30 GHz. To demonstrate the flexible beam-forming capability of the proposed metasurface reflectors, illustrative examples of fixed beam steering with varying reflection magnitudes, and asymmetric dual-beam patterns with specified reflection magnitude, reflection angles and beam-widths, are successfully shown. Compared to the standard method based on polarization rotation and resistive loadings with discrete values, the proposed technique does not generate undesired cross-polarization field reflection, and provides a continuous magnitude tuning including full absorption, along with wide phase coverage.</div>

Scaling Properties of Silicon Microring CROWs (Project Report 0925399-Y3)

The research outcomes of this NSF-funded project include the realization of long silicon coupled-resonator optical waveguides and a study of their optical transmission and localization properties.