Investigation of Side Wall Roughness Effect on Optical Losses in a Multimode Si<sub>3</sub>N<sub>4</sub> Waveguide Formed on a Quartz Substrate

This article presents the results of the study of the influence of the most significant parameters of the side wall roughness of an ultra-thin silicon nitride lightguide layer of multimode integrated optical waveguides with widths of 3 and 8 microns. The choice of the waveguide width was made due to...

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Bibliographic Details
Main Authors: Anastasia Yakuhina, Alexey Kadochkin, Vyacheslav Svetukhin, Dmitry Gorelov, Sergey Generalov, Vladimir Amelichev
Format: Article
Language:English
Published: MDPI AG 2020-11-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/7/4/104
Description
Summary:This article presents the results of the study of the influence of the most significant parameters of the side wall roughness of an ultra-thin silicon nitride lightguide layer of multimode integrated optical waveguides with widths of 3 and 8 microns. The choice of the waveguide width was made due to the need to provide multimode operation for telecommunication wavelengths, which is necessary to ensure high integration density. Scattering in waveguide structures was measured by optical frequency domain reflectometry (OFDR) of a backscattering reflectometer. The finite difference time domain method (FDTD) was used to study the effect of roughness parameters on optical losses in fabricated waveguides, the roughness parameters that most strongly affect optical scattering were determined, and methods of its significant reduction were specified. The prospects for implementing such structures on a quartz substrate are justified.
ISSN:2304-6732