PhD Defense by Anders Simonsen
Abstract: Transducing electrical signals to the optical domain has many applications because optical technology offers superior signal transmission and immunity to electromagnetic interference. Relevant applications include radio astronomy, navigation, classical and quantum communication, and Magnetic-Resonance Imaging (MRI). This thesis presents a method for such electro-optical transduction based on a mechanical element, and then focuses on implementing the transduction in MRI where it can solve challenges related to preamplifier electronics, cable loss, and radio-frequency noise. However, moving into an MRI scanner requires a robust and transportable experimental setup, while also demanding high sensitivity. It will be shown that resonant electro- and optomechanical transduction offer a suitable sensitivity for MRI and other sensing applications. Additionally, the fabrication of an integrated device will be described, a device that both simplifies and miniaturizes the full setup and enables electro-mechano-optical transduction in a commercial MRI scanner.