High Energy Irradiation Effects on Silicon Photonic Passive Devices

TL;DR

This study investigates how high-energy neutron and gamma-ray irradiation affect silicon photonic passive devices, revealing that SiO2 cladding enhances radiation tolerance and causes specific wavelength shifts in resonators and interferometers.

Contribution

It provides new insights into the radiation responses of silicon photonic devices, highlighting the protective role of SiO2 cladding under high-energy irradiation.

Findings

Blue wavelength shifts occur after neutron irradiation.

SiO2 cladding improves device radiation tolerance.

Neutron irradiation causes slight crystal symmetry changes.

Abstract

In this work, the radiation responses of silicon photonic passive devices built in silicon-on-insulator (SOI) technology are investigated through high energy neutron and 60Co gamma-ray irradiation. The wavelengths of both micro-ring resonators (MRRs) and Mach-Zehnder interferometers (MZIs) exhibit blue shifts after high-energy neutron irradiation to a fluence of 1*1012 n/cm2; the blue shift is smaller in MZI devices than in MRRs due to different waveguide widths. Devices with SiO2 upper cladding layer show strong tolerance to irradiation. Neutron irradiation leads to slight changes in the crystal symmetry in the Si cores of the optical devices and accelerated oxidization for devices without SiO2 cladding. A 2 um top cladding of SiO2 layer significantly improves the radiation tolerance of these passive photonic devices.