PhD Thesis Defense

Zoom link: https://caltech.zoom.us/j/85483016478

Fundamental physical laws dictate the performance bounds of all technologies. Over the last century, advances in nanotechnology and integrated circuits have driven the performance of communications, sensing, and computing toward these bounds. As scaling continues, classical limits are increasingly constraining further improvements. The advent of quantum technologies opens paths to overcoming some of these constraints and to building technologies that operate at the fundamental physical limits. This thesis develops a unified framework for these limits and demonstrates large-scale integrated photonic-electronic systems that approach them. In communications, quantum coherent transceivers are introduced and demonstrated that transmit and receive non-classical light to surpass the Shannon limit and approach the Holevo limit. In sensing, quantum phased arrays—coherent antenna arrays that transmit or receive quantum fields over free space—are introduced and demonstrated with up to 32 elements for squeezed light imaging, beamforming and beamsteering, overcoming the standard quantum limit to approach the Heisenberg limit and enabling protocols for free-space quantum sensing, quantum communications, and quantum information processing. In computing, large-scale crosstalk-corrected thermo-optic phase shifter arrays and a 256-element programmable photonic mesh are demonstrated, addressing the scaling challenges of integrated photonic-electronic processors. For each system, I present the underlying theory, design, experiments, and applications, and outline a vision for how these technologies can be practically deployed in the future.