Photonic integration of divacancy color centers in silicon carbide and heterogeneous integration of lithium niobate on III-V/Si substrates

In this thesis, I present two independent projects carried out during my second year of the MS program. The first is titled "Photonic Integration of Divacancy Color Centers in Silicon Carbide", and the second focuses on the "Heterogeneous Integration of Lithium Niobate on III-V/Si Substrates". Chapter 1 covers the work on divacancy centers in silicon carbide (SiC), while Chapter 2 discusses the heterogeneous integration effort. In Chapter 1, I begin by laying out the motivation for using solid-state defects as promising candidates for quantum repeaters. An ideal quantum repeater requires a qubit that can interface with light and a robust quantum memory that’s well-coupled to it. Among the various systems explored, divacancy centers in SiC stand out due to their unique optical, electrical, and quantum properties. The bulk of this chapter focuses on unpacking each of these aspects. That said, most of the described work is based on divacancy centers in bulk SiC, and an understanding of how they perform in nanostructured environments is limited. Our short-term goal is to develop high-quality factor, low mode volume, and noise-resilient nanophotonic devices on a silicon carbide-on-insulator platform. This direction is motivated by the potential of photonic integrated color centers to make quantum communication more scalable and efficient. Towards the end of the chapter, I describe the fabrication progress we've made in the past few months toward this goal. Chapter 2 shifts focus to our efforts on integrating thin-film lithium niobate (TFLN) with III-V/Si substrates. TFLN on insulator (typically on silicon dioxide) is emerging as a versatile photonics platform, especially for data communication. Lithium niobate offers low-loss propagation, a high electro-optic coefficient, and supports efficient frequency comb generation - making it a strong candidate for modulators and comb sources. When combined with III-V gain materials, this platform opens up the possibility for compact, low-cost transceivers, with promising applications in commercial data centers.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Misra, Yuvraj

Contributors dc:contributor

• Anderson, Chris

• Quantum Photonics
• Color Centers
• Silicon Carbide
• Solid-state Defects
• Photonic Integrated Circuits
• Lithium Niobate
• Transceivers
• Co-packaged Optics

Statement dc:rights

• Copyright 2025 Yuvraj Misra

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129637

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129637