Design and Analysis of Free-space Optical Communications Systems for Next Generation Short-range Wireless Networks

This dissertation focuses on indoor free-space optical communications systems for use in short range wireless networks. We propose that current radio frequency wireless links be augmented or replaced with optical frequency links due to overcrowding in the radio frequency spectrum. Optical frequencies contain hundreds of terahertz of unregulated bandwidth and offer a physical layer of protection due to the inherently line-of-sight nature of near infrared light. We first present a hybrid optical and radio frequency link based on inexpensive LEDs in which a downlink is established optically, while the uplink is routed through preexisting radio frequency channels. Second, an all optical dual channel laser-based communication system is implemented consisting of a medium bandwidth wide-angle optical femtocell and a high-speed line-of-sight optical attocell. This approach balances the diverse needs of end users by providing links optimized for both mobility and bandwidth. Lastly, we demonstrate a high-power vertical cavity surface emitting laser (VCSEL) array optical transmitter for use in optical femtocells. A complimentary design for a distributed current laser driver is also presented.

Major Advisor: Alan Wang
Committee: Thinh Nguyen
Committee: Arun Natarajan
Committee: Matthew Johnston
GCR: Yun-Shik Lee