Optical cavities are highly sensitive platforms for atom–photon interactions and precision measurement, but scalability is limited by fabrication challenges in forming high-quality micro-optical surfaces. Here, we present the development of an iterative laser milling technique to advance fiber-based Fabry–Perot cavities, providing precise control of mirror geometries on ~50 µm radius scales while producing concave, spherical optical surfaces with large radii of curvature (1–2 mm) suitable for longer cavity lengths. This approach integrates phase-shifting optical profilometry, precision motion control, and CO₂ laser ablation to iteratively measure and refine surface profiles, achieving micro-mirrors with 1–3 nm root-mean-square surface error for high-finesse cavity operation. These capabilities support atom-chip platforms for confined atom interferometry through atom transport and coupling to integrated microcavity systems.  

 

The iterative framework further enables the fabrication of arbitrary surface geometries through algorithmic and analytical surface definitions, extending beyond spherical mirrors to application-specific photonic structures, including nontrivial surface profiles and spatially structured optical geometries, establishing a generalized platform for custom photonic interfaces. The versatility of this approach is demonstrated through the fabrication of microcavity arrays on bulk substrates, enabling scalable cavity architectures with improved passive stability and reduced environmental sensitivity.  

 

To address optical mode matching in these cavity systems, two complementary approaches are developed. First, gradient-index optical components are characterized and integrated to provide controlled beam shaping and efficient fiber-to-cavity coupling in modular architectures. Second, a fully integrated photonic approach is explored through ultrafast laser inscription, enabling the fabrication of waveguides and mode-matched three-dimensional aperiodic volume gratings within bulk substrates. These structures are designed using iterative phase-retrieval methods and simulations to achieve precise mode transformation and passive alignment between waveguide outputs and cavity modes, establishing a monolithic solution for scalable photonic integration. 

 

Together, these results establish a flexible fabrication platform for fiber-based and integrated optical cavities, advancing scalable architectures for cavity quantum electrodynamics and quantum sensing applications. 

 

Meagan (Parker) Plummer received her Bachelor of Science degree in Physics from Weber State University in 2017. As an undergraduate, she conducted research on NASA-funded high-altitude balloon payloads and contributed to work on thin films and perovskite solar cells. She was awarded the Dr. Gali Physics Scholarship and later joined the University of Utah as a research assistant, where she received the William G. Holt Fellowship and worked on nanostructured solar cells. She then gained industry experience assisting in managing operations and helping lead multi-company initiatives before returning to research in semiconductor materials, contributing to a 2020 publication on quasi-phase-matched infrared frequency conversion.  

She then joined the Universities Space Research Association (USRA) as a contractor supporting the Air Force Research Laboratory (AFRL), where she conducted cold atom research while pursuing her graduate studies in the Optical Science and Engineering program at the University of New Mexico. Her doctoral research advanced the development of integrated optical cavity systems for atom–photon interfaces, focusing on the design and fabrication of high-finesse optical cavities and embedded photonic structures for scalable quantum sensing. Her work established a laser-based microfabrication platform enabling precision control of optical surfaces and subsurface waveguide architectures, supporting the realization of compact, robust, and nondestructive quantum measurement systems.