Ultrashort low-loss \u03a8 gates for linear optical logic on Si photonics platform

Shota Kita,Kenta Takata,Akihiko Shinya,Kengo Nozaki,Masaya Notomi

doi:10.1038/s42005-020-0298-2

Shota Kita, Kenta Takata + Show 3 more

Open Access

https://doi.org/10.1038/s42005-020-0298-2

Copy DOI

Abstract

Nonlinear optical gates are usually considered as fundamental building blocks for universal optical computation. However, the performance is severely limited by small optical nonlinearity, thereby bounding their operation speed, consumption energy, and device size. In this paper, we propose and experimentally demonstrate linear optical logic operations with ~3 μm-long Si wire “Ψ” gates consist of 3 × 1 optical combiners including auxiliary bias port, which maximizes the binary contrast of the output in telecom wavelength. We have demonstrated 20 Gbps Boolean “AND” operation with experimentally measured small signal loss (1.6 dB experimentally). A single Ψ gate can perform representative Boolean operations by changing the bias power and relative phases. We have also demonstrated wavelength-independent operation by seven wavelengths, which leads to wavelength-division multiplexed parallel computation. This ultrashort, highly-integrable, low-loss, and energy-efficient optical logic gates pave the way for ultralow latency optical pattern matching, recognition, and conversion.

Highlights

Nonlinear optical gates are usually considered as fundamental building blocks for universal optical computation
Most previous optical computation schemes rely on optical nonlinearity or an electro-optic effect that generally makes optical gates longer and energy-consuming[6]
We propose and demonstrate high-bit rate optical Boolean logic operations (AND, NOR, and XNOR) realized by ultrashort (~3 μm long) Si wire-based linear “Ψ“ gates implemented on a low-loss Si photonics circuit

Summary

Introduction

Nonlinear optical gates are usually considered as fundamental building blocks for universal optical computation. We have demonstrated wavelengthindependent operation by seven wavelengths, which leads to wavelength-division multiplexed parallel computation This ultrashort, highly-integrable, low-loss, and energy-efficient optical logic gates pave the way for ultralow latency optical pattern matching, recognition, and conversion. A simple beam splitter can perform various types of approximate Boolean logic gates as a result of optical interference Since these gates do not rely on optical nonlinearity, several advantages can be expected namely they can be extremely short, thereby leading to an ultrashort computation delay. We propose and demonstrate high-bit rate optical Boolean logic operations (AND, NOR, and XNOR) realized by ultrashort (~3 μm long) Si wire-based linear “Ψ“ gates implemented on a low-loss Si photonics circuit. Since the achieved Ψ gates are very short and integrated/combined with Si photonic circuits, our result reveals the potential of linear optic circuits for ultralow-latency computation

Methods

Results

Conclusion