Advancing optical interconnects: Exploring low-loss 3D photonic waveguides, loop mirrors, and distributed Bragg reflectors

Photonic integrated circuits (PICs) are gaining traction in the areas of computing and datacom as ever-increasing demands for high-speed computation and data are pushing electrical interconnects to their limits. One promising method for fabricating high performance PICs is subsurface controllable refractive index via beam exposure (SCRIBE). The SCRIBE method leverages two-photon polymerization to write photonic devices within a porous substrate. SCRIBE can be used to fabricate dense, fully volumetric (3D) integrated photonic circuits. Further, SCRIBE has unique refractive index control that allows for the creation of gradient refractive index photonic devices. In this work, current SCRIBE fabrication will be described and compared to the original publications that developed the method. From there, a device theory chapter will present the device physics for the three devices of interest in this thesis: waveguides, loop mirrors, and distributed Bragg reflectors. These devices are fundamental building blocks for PICs that provide basic functionality, from light transport to highly reflective surfaces. These devices can also be used in the characterization of optical properties such as effective refractive index. We then explore device characterization, providing detailed information regarding the development of alignment tools and methods that have greatly improved the characterization of SCRIBE devices. Next, experimental results are discussed that have guided the path toward low-loss waveguides, loop mirrors, and distributed Bragg reflectors. Within this discussion, there is a focus on the high-level lessons of fabricating photonic devices with the SCRIBE method. Lastly, areas requiring further study and literature gaps are identified in the hopes that this work will continue far into the future.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Holley, Mason Lee

Contributors dc:contributor

• Goddard, Lynford L

• Direct Laser Writing
• Photonic Integrated Circuits
• Low-loss Waveguides
• Loop Mirror
• Distributed Bragg Reflector
• Optical Alignment
• Multimode Interferometer
• Sagnac Interferometer

Statement dc:rights

• Copyright 2023 Mason Lee Holley

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/121282

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F121282