Engineering Illumination Through Multimode Fibers for Imaging and Metrology

Multimode fibers support the propagation of hundreds or thousands of optical modes, resulting in complex interference and highly scrambled output fields. While such complexity has traditionally been considered a limitation for imaging and precise light delivery, recent advances in photonics and computational optics have transformed multimode fibers into controllable optical systems for engineered illumination. In this thesis, the potential of multimode fibers as flexible tools for illumination control in imaging and optical metrology is explored. The central idea of this work is that illumination should not be treated as a fixed property of an optical system, but rather as a parameter that can be manipulated and designed depending on the application. In this study, several key challenges related to illumination engineering through multimode fibers are addressed. The work investigates how complex light propagation through multimode fibers can be controlled and exploited for imaging, computational reconstruction, and phase retrieval. Different approaches for generating, manipulating, and utilizing complex illumination fields are explored, demonstrating the potential of multimode fibers not only as passive waveguides, but also as active optical elements for advanced imaging and metrology applications.