Optical meta-waveguides for integrated photonics and beyond

AbstractThe growing maturity of nanofabrication has ushered massive sophisticated optical structures available on a photonic chip. The integration of subwavelength-structured metasurfaces and metamaterials on the canonical building block of optical waveguides is gradually reshaping the landscape of photonic integrated circuits, giving rise to numerous meta-waveguides with unprecedented strength in controlling guided electromagnetic waves. Here, we review recent advances in meta-structured waveguides that synergize various functional subwavelength photonic architectures with diverse waveguide platforms, such as dielectric or plasmonic waveguides and optical fibers. Foundational results and representative applications are comprehensively summarized. Brief physical models with explicit design tutorials, either physical intuition-based design methods or computer algorithms-based inverse designs, are cataloged as well. We highlight how meta-optics can infuse new degrees of freedom to waveguide-based devices and systems, by enhancing light-matter interaction strength to drastically boost device performance, or offering a versatile designer media for manipulating light in nanoscale to enable novel functionalities. We further discuss current challenges and outline emerging opportunities of this vibrant field for various applications in photonic integrated circuits, biomedical sensing, artificial intelligence and beyond.

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PLASMONIC RACETRACK RESONATOR FOR APPLICATION TO PHOTONIC INTEGRATED CIRCUITS AT SUB-WAVELENGTH

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863510005790 ◽

2010 ◽

Vol 19 (04) ◽

pp. 583-588 ◽

Cited By ~ 7

Author(s):

HIROYUKI OKAMOTO ◽

KENZO YAMAGUCHI ◽

MASANOBU HARAGUCHI ◽

TOSHIHIRO OKAMOTO

Keyword(s):

Integrated Circuits ◽

Finite Difference Time Domain ◽

Cavity Mode ◽

Ring Resonator ◽

Photonic Integrated Circuits ◽

Plasmonic Waveguides ◽

Order Of Magnitude ◽

Racetrack Resonator ◽

Difference Time ◽

Sub Wavelength

A racetrack resonator, several hundred nanometers in size and composed of plasmonic waveguides is presented. The wavelength spectrum of the plasmonic racetrack resonator has been numerically evaluated by using finite-difference time-domain method. As compared to the conventional plasmonic ring resonator, the output light intensity of the proposed plasmonic racetrack resonator is greater by almost one order of magnitude. The cavity mode of the plasmonic racetrack resonator has also been investigated.

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Graphene-based plasmonic waveguides for photonic integrated circuits

Optics Express ◽

10.1364/oe.19.024557 ◽

2011 ◽

Vol 19 (24) ◽

pp. 24557 ◽

Cited By ~ 100

Author(s):

Jin Tae Kim ◽

Sung-Yool Choi

Keyword(s):

Integrated Circuits ◽

Photonic Integrated Circuits ◽

Plasmonic Waveguides

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Tunable hollow optical waveguides for photonic integrated circuits

10.1117/12.572408 ◽

2004 ◽

Author(s):

Fumio Koyama

Keyword(s):

Integrated Circuits ◽

Optical Waveguides ◽

Photonic Integrated Circuits

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Liquid crystal tunable claddings for polymer integrated optical waveguides

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.209 ◽

2019 ◽

Vol 10 ◽

pp. 2163-2170 ◽

Cited By ~ 1

Author(s):

José Manuel Otón ◽

Manuel Caño-García ◽

Fernando Gordo ◽

Eva Otón ◽

Morten Andreas Geday ◽

...

Keyword(s):

Integrated Circuits ◽

Integrated Circuit ◽

Optical Waveguides ◽

Optical Switching ◽

Photonic Integrated Circuits ◽

Optical Signals ◽

Optical Functions ◽

Integrated Optical ◽

Integrated Optical Waveguides ◽

Variable Coupling

Optical waveguides in photonic integrated circuits are traditionally passive elements merely carrying optical signals from one point to another. These elements could contribute to the integrated circuit functionality if they were modulated either by variations of the core optical properties, or by using tunable claddings. In this work, the use of liquid crystals as electro-optically active claddings for driving integrated waveguides has been explored. Tunable waveguides have been modeled and fabricated using polymers. Optical functions such as variable coupling and optical switching have been demonstrated.

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High-efficiency broadband light coupling between optical fibers and photonic integrated circuits

Nanophotonics ◽

10.1515/nanoph-2018-0075 ◽

2018 ◽

Vol 7 (12) ◽

pp. 1845-1864 ◽

Cited By ~ 26

Author(s):

Gyeongho Son ◽

Seungjun Han ◽

Jongwoo Park ◽

Kyungmok Kwon ◽

Kyoungsik Yu

Keyword(s):

Integrated Circuits ◽

Optical Fibers ◽

Optical Switching ◽

High Efficiency ◽

Photonic Integrated Circuits ◽

Coupling Efficiency ◽

Optical Signal ◽

Coupling Methods ◽

Light Coupling ◽

Waveguide Coupling

AbstractEfficient light energy transfer between optical waveguides has been a critical issue in various areas of photonics and optoelectronics. Especially, the light coupling between optical fibers and integrated waveguide structures provides essential input-output interfaces for photonic integrated circuits (PICs) and plays a crucial role in reliable optical signal transport for a number of applications, such as optical interconnects, optical switching, and integrated quantum optics. Significant efforts have been made to improve light coupling properties, including coupling efficiency, bandwidth, polarization dependence, alignment tolerance, as well as packing density. In this review article, we survey three major light coupling methods between optical fibers and integrated waveguides: end-fire coupling, diffraction grating-based coupling, and adiabatic coupling. Although these waveguide coupling methods are different in terms of their operating principles and physical implementations, they have gradually adopted various nanophotonic structures and techniques to improve the light coupling properties as our understanding to the behavior of light and nano-fabrication technology advances. We compare the pros and cons of each light coupling method and provide an overview of the recent developments in waveguide coupling between optical fibers and integrated photonic circuits.

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Transverse and Quantum Localization of Light: A Review on Theory and Experiments

Frontiers in Physics ◽

10.3389/fphy.2021.715663 ◽

2021 ◽

Vol 9 ◽

Author(s):

Taira Giordani ◽

Walter Schirmacher ◽

Giancarlo Ruocco ◽

Marco Leonetti

Keyword(s):

Optical Fibers ◽

Electromagnetic Waves ◽

Degrees Of Freedom ◽

Quantum Communication ◽

Single Photon ◽

Localization Length ◽

Single Mode ◽

Localized States ◽

Direct Laser ◽

Quantum Localization

Anderson localization is an interference effect yielding a drastic reduction of diffusion—including complete hindrance—of wave packets such as sound, electromagnetic waves, and particle wave functions in the presence of strong disorder. In optics, this effect has been observed and demonstrated unquestionably only in dimensionally reduced systems. In particular, transverse localization (TL) occurs in optical fibers, which are disordered orthogonal to and translationally invariant along the propagation direction. The resonant and tube-shaped localized states act as micro-fiber-like single-mode transmission channels. Since the proposal of the first TL models in the early eighties, the fabrication technology and experimental probing techniques took giant steps forwards: TL has been observed in photo-refractive crystals, in plastic optical fibers, and also in glassy platforms, while employing direct laser writing is now possible to tailor and “design” disorder. This review covers all these aspects that are today making TL closer to applications such as quantum communication or image transport. We first discuss nonlinear optical phenomena in the TL regime, enabling steering of optical communication channels. We further report on an experiment testing the traditional, approximate way of introducing disorder into Maxwell’s equations for the description of TL. We find that it does not agree with our findings for the average localization length. We present a new theory, which does not involve an approximation and which agrees with our findings. Finally, we report on some quantum aspects, showing how a single-photon state can be localized in some of its inner degrees of freedom and how quantum phenomena can be employed to secure a quantum communication channel.

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