Nonduplicate Polarization-Diversity 32 × 32 Silicon Photonics Switch Based on a SiN/Si Double-Layer Platform

Keijiro Suzuki,Miyoshi Seki,Shu Namiki,Hitoshi Kawashima,Satoshi Suda,Kazuhiro Ikeda,Ryotaro Konoike,Koji Yamada,Shigeru Saitoh,Minoru Ohtsuka,Nobuyuki Yokoyama,Hiroyuki Matsuura

doi:10.1109/jlt.2019.2934763

Keijiro Suzuki, Miyoshi Seki + Show 10 more

Open Access

https://doi.org/10.1109/jlt.2019.2934763

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Abstract

We fabricate and characterize a polarization-diversity 32 × 32 silicon photonics switch by newly introducing SiN overpass waveguides onto our nonduplicate polarization-diversity path-independent insertion-loss switch. The SiN overpass waveguides are used to simplify the optical paths with a uniform path length between the edge couplers and the switch matrix and significantly reduce the number of waveguide intersections. The switch chip is fabricated using a 300-mm silicon-on-insulator wafer pilot line. The fabricated switch comprises more than 7,600 components, making this the largest ever complementary-metal-oxide-semiconductor-based silicon photonics circuit. The switch chip is electrically and optically packaged and evaluated for a sampled port connection with 32 paths, with an average on-chip loss of ∼35 dB and an average polarization-dependent loss of 3.2 dB where 75% of the measured paths exhibit a loss of less than 3 dB. The differential group delay is measured to be 1.7 ps. The performance can be further improved by optimizing the device design.

Highlights

A STRICTLY nonblocking multiport optical switch will be a key enabler for handling a large amount of data flow in telecom and datacom applications with low electric power consumption [1]
Some packaging technologies developed for electronic devices are available for large-scale silicon photonics switches with a high pin count
We proposed a novel “nonduplicate” polarization-diversity circuit based on the path-independent insertion loss (PILOSS) topology [8]

Summary

INTRODUCTION

A STRICTLY nonblocking multiport optical switch will be a key enabler for handling a large amount of data flow in telecom and datacom applications with low electric power consumption [1]. Some packaging technologies developed for electronic devices are available for large-scale silicon photonics switches with a high pin count. In a polarization-diversity scheme, two identical switch matrices are generally required to handle two orthogonally polarized components This becomes a problem, for high-radix switches, such as 32 × 32 ports, because the area and numbers of control pins and circuits required for the switch are twice those required for a single switch matrix. We previously demonstrated a nonduplicate polarization-insensitive 8 × 8 switch [8] This diversity scheme has one drawback: excessive intersections on a particular path (7N – 4 intersections for an N × N switch) due to the embedded access waveguides in the switch matrix. The switch chip is designed and fabricated, and its polarization characteristics are evaluated

SWITCH STRUCTURE AND FABRICATED DEVICE

SiN Devices

Crosstalk

CONCLUSION