Events Calendar

ECE PhD Prospectus Defense: Chris Schwarze

Title: Directionally-unbiased linear-optical scatterers for integrated quantum photonics applications

Presenter: Chris Schwarze

Advisor: Professor Alexander Sergienko

Chair: Professor Roberto Paiella

Committee: Professor Alexander Sergienko, Professor Michelle Sander, Professor Roberto Paiella, Professor David Simon, Stonehill College

Abstract: Traditional linear-optical scattering devices such as beam-splitters, phase-shifters, ring resonators, and meshes of Mach-Zehnder interferometers are designed to transfer all light between distinct input and output field modes. These so-called feed-forward or directionally-biased devices comprise the principal components of many important optical systems, including interferometers, on-chip photonic meshes, imaging systems, and optical communication systems. Being feed-forward, these components are typically designed to minimize back-reflections. However, a novel class of directionally-unbiased linear optical scatterers distinguished by their strong back-reflections has been recently considered. Through these back-reflections and increased dimensionality, these unbiased optical multiports have taken a key role in the design of novel systems for enhanced higher-dimensional interferometry. These devices also exhibit interesting two-photon quantum interference effects, enabling routing of entangled optical states. In this prospectus, we outline the latest progress in the fabrication of an on-chip unbiased four-port, a particularly symmetric device known as the Grover coin. We will discuss recently proposed applications of this device, such as a generalized Michelson interferometer that exhibits super-resolution phase sensitivity as well as a phase-only analogue which has been experimentally investigated. An algorithm for computing the output scattering state of an arbitrary scattering graph is illustrated, which can be used to design and understand high-dimensional optical scattering devices. Later, we will integrate optical phase shifters with the Grover coin. After a complete characterization of the device, we will utilize it for demonstrating new schemes in super-resolution sensing and quantum networking.