Date:Wednesday, November 5, 2025

Time: 9:00 AM to 11:00 AM

Location: CHTM, Room 103 

Committee:

Dr. Tara Drake, Department of Physics & Astronomy, UNM  
Dr. Victor Acosta, Department of Physics & Astronomy, UNM 
Dr. Tito Busani, Department of Electrical and Computer Engineering, UNM
Dr. Daniel Feezell, Department of Electrical and Computer Engineering, UNM 

Abstract:

Optical frequency combs serve as a ruler of light with equidistant frequency lines and have a multitude of applications from optical metrology to medical diagnostics. Initially, frequency combs were based on mode-locked lasers, which require elaborate optical setups in specialized laboratories, but with recent advancements in integrated photonics, frequency combs can now be created in chip-scale systems (microcombs) using Kerr nonlinearity in high-Q resonators. These miniaturized systems come with their own set of challenges, including heterogeneous integration of active and passive components, increased propagation losses, enhanced thermal effects, and the extension of microcombs to visible wavelengths. In this dissertation, I will focus on addressing some of the challenges in silicon nitride (SiN) resonators. The first part of this thesis focuses on the fabrication of low-loss, high-Q silicon nitride resonators and the impact of fabrication process parameters on the quality of devices. Then I present the design of SiN resonators near visible wavelengths to get octave spanning spectra with dual harmonic dispersive waves. The final part of this dissertation dives into how thermal effects complicate the dynamics of comb formation, models thermal fluctuations using a finite element method COMSOL simulation and compares simulation results to experimental measurements.

Biography: