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Analog coupled oscillator based weighted Ising machine

October 15, 2019
  |
Journal Article
Author:
Jeffrey B. Chou
…
Published in:
Sci. Rep., Vol. 9, No. 1, 15 October 2019, 14786.
Topic:
computing
R&D area:
R&D group:

Summary

We report on an analog computing system with coupled non-linear oscillators which is capable of solving complex combinatorial optimization problems using the weighted Ising model. The circuit is composed of a fully-connected 4-node LC oscillator network with low-cost electronic components and compatible with traditional integrated circuit technologies. We present the theoretical modeling, experimental characterization, and statistical analysis our system, demonstrating single-run ground state accuracies of 98% on randomized MAX-CUT problem sets with binary weights and 84% with 5-bit weight resolutions. Solutions are obtained within 5 oscillator cycles, and the time-to-solution has been demonstrated to scale directly with oscillator frequency. We present scaling analysis which suggests that large coupled oscillator networks may be used to solve computationally intensive problems faster and more efficiently than conventional algorithms. The proof-of-concept system presented here provides the foundation for realizing such larger scale systems using existing hardware technologies and could pave the way towards an entirely novel computing paradigm.
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Summary

We report on an analog computing system with coupled non-linear oscillators which is capable of solving complex combinatorial optimization problems using the weighted Ising model. The circuit is composed of a fully-connected 4-node LC oscillator network with low-cost electronic components and compatible with traditional integrated circuit technologies. We present the...

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Analog coupled oscillator based weighted Ising machine

Broadband transparent optical phase change materials

May 14, 2017
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Conference Paper
Author:
Yifei Zhang
…
Published in:
CLEO: Conf. on Lasers and Electro-Optics, 14-19 May 2017.
Topic:
optics
R&D area:
R&D group:

Summary

We report a new group of optical phase change materials Ge-Sb-Se-Te (GSST) with low loss from telecom bands to LWIR. We further demonstrated GSST-integratedSiN photonics with significantly improved switching performance over conventional GST alloys.
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Summary

We report a new group of optical phase change materials Ge-Sb-Se-Te (GSST) with low loss from telecom bands to LWIR. We further demonstrated GSST-integratedSiN photonics with significantly improved switching performance over conventional GST alloys.

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Broadband transparent optical phase change materials

Large enhancement of third-order nonlinear effects with a resonant all-dielectric metasurface

November 1, 2016
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Journal Article
Author:
Samad Jafar-Zanjani
…
Published in:
AIP Adv., Vol. 6, No. 11, 1 November 2016, 115213.
Topic:
advanced materials
R&D area:
R&D group:

Summary

A novel low-profile nonlinear metasurface, consisting of a single-layer of all-dielectric material, is proposed and numerically investigated by a nonlinear full-wave finite-difference time-domain (FDTD) method. The proposed metasurface is transparent for low, and opaque for high values of incident light intensity. The metasurface design is broadly applicable to enhancement of intrinsic nonlinearities of any material with a sufficiently high refractive index contrast. We illustrate the ability of this design to enhance intrinsic nonlinear absorption of a transition metal oxide, vanadium pentoxide (V2O5), with resonant metasurface elements. The complex third-order nonlinear susceptibility (x^(3)) for V2O5, representing both nonlinear refraction and absorption is considered in FDTD simulations. Our design achieves high initial transparency (>90%) for low incident light intensity. An order of magnitude decrease in the required input light intensity threshold for nonlinear response of the metasurface is observed in comparison with an unpatterend film. The proposed all-dielectric metasurface in this work is ultrathin and easy to fabricate. We envision a number of applications of this design for thin film coatings that offer protection against high-power laser radiation.
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Summary

A novel low-profile nonlinear metasurface, consisting of a single-layer of all-dielectric material, is proposed and numerically investigated by a nonlinear full-wave finite-difference time-domain (FDTD) method. The proposed metasurface is transparent for low, and opaque for high values of incident light intensity. The metasurface design is broadly applicable to enhancement of...

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Large enhancement of third-order nonlinear effects with a resonant all-dielectric metasurface

Electrically switchable diffractive waveplates with metasurface aligned liquid crystals

October 17, 2016
  |
Journal Article
Author:
Jeffrey B. Chou
…
Published in:
Opt. Express, Vol. 24, No. 21, 17 October 2016, 24265-24273.
Topic:
lithography
R&D area:
R&D group:

Summary

Diffractive waveplates and equivalent metasurfaces provide a promising path for applications in thin film beam steering, tunable lenses, and polarization filters. However, fixed metasurfaces alone are unable to be tuned electronically. By combining metasurfaces with tunable liquid crystals, we experimentally demonstrate a single layer device capable of electrically switching a diffractive waveplate design at a measured peak diffraction efficiency of 35%, and a minimum switching voltage of 10V. Furthermore, the nano-scale metasurface aligned liquid crystals are largely independent of variations in wavelength and temperature. We also present a computational analysis of the efficiency limits of liquid crystal based diffractive waveplates, and compare this analysis to experimental measurements.
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Summary

Diffractive waveplates and equivalent metasurfaces provide a promising path for applications in thin film beam steering, tunable lenses, and polarization filters. However, fixed metasurfaces alone are unable to be tuned electronically. By combining metasurfaces with tunable liquid crystals, we experimentally demonstrate a single layer device capable of electrically switching a...

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Electrically switchable diffractive waveplates with metasurface aligned liquid crystals
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