<div>The purpose of this thesis was to investigate the possibility of Optical Frequency Identification (OFID) technology being used as a communication pathway for devices in LiFi systems that serve to open alternative transmission paths for Internet-of-Things infrastructure. LiFi or light-fidelity, plays off the concept of wireless-fidelity, commonly known as WiFi, and follows the trend of moving to higher frequencies within the electromagnetic spectrum. LiFi lies within the visual light and infrared wavelength range, which can be referred to as the nanometer wave range. The developed optical communication testbed is a proof of concept showing that OFID technology, enabled by Gallium Arsenide solar cell emission, can communicate with Visual Light Communication (VLC) systems. The scope of the work entails the development of a testbed for a custom optical communications testbed for OFID linked to VLC communication by sending transmissions via powerline modulation. An optical receiver circuit was developed and tested, and integration and testing for powerline communication and LED luminaire were successful. Manchester encoded data was sent at 4800 bit rate optically from an infrared light source, received by the developed receivers and was decoded. Information was successfully transmitted over powerline from computer terminal to LED luminaire output at 2400, 3600, 4800, 7200, and 9600 bit rate. Integration of these communication links did not occur due to Purdue University closure of campus related activities from COVID-19.<br></div>

Modern fiber-optic networks leverage massive parallelization of communications channels in the spectral domain, as well as low-noise recovery of optical signals, to achieve high rates of information transfer. However, quantum information imposes additional constraints on optical transport networks – the no-cloning theorem forbids use of signal regeneration and many network protocols are premised on operations like Bell state measurements that prize spectral indistinguishability. Consequently, a key challenge for quantum networks is identifying a path to high-rate and high-fidelity quantum state transport.<div><br></div><div>To bridge this gap between the capabilities of classical and quantum networks, we developed techniques that harness spectral multiplexing of quantum channels, as well as that support frequency encoding. In relation to the former, we demonstrated reconfigurable connectivity over arbitrary subgraphs in a multi-user quantum network. In particular, through flexible provisioning of the pair source bandwidth, we adjusted the rate at which entanglement was distributed over any user-to-user link. To facilitate networking protocols compatible with both spectral multiplexing and frequency encoding, we synthesized a Bell state analyzer based on mixing outcomes that populate different spectral modes, in contrast to conventional approaches that are based on mixing outcomes that populate different spatial paths. This advance breaks the tradeoff between the fidelity of remote entanglement and the spectral distinguishability of photons participating in a joint measurement.<br></div><div><br></div><div>Finally, we take steps toward field deployment by developing photonic integrated circuits to migrate the aforementioned functionality to a chip-scale platform while also achieving the low loss transmission and high-fidelity operation needed for practical quantum networks.<br></div>