Sachs, A. Morgan2021-09-302021-09-302021-09-302021-09-13http://hdl.handle.net/10012/17592In this work, we employ the Unruh-DeWitt (UDW) detector model to various ends. We present applications of this relativistic detector model to quantum optics, including decoherence in optical cavities and non-linear quantum optics. We also relate an array of UDW-like models to the usual UDW model, which has the immediate consequence of yielding a tool to probe the entanglement structure of the Fermionic field, as well as many others. We are also able to show that entanglement harvesting is robust under dispersive effects, paving the way for tabletop experiments of the protocol.enentanglementquantum field theoryUnruh-DeWitt detectorquantum informationrelativistic quantum informationquantum opticsnon-linear opticsanalog gravityQuantum entanglementQuantum field theoryQuantum computingRelativistic quantum theoryQuantum opticsDoctoral Thesis