High-Bitrate Photodetection in Ultraviolet-to-Visible for Optical Wireless Communication
AuthorsKang, Chun Hong
AdvisorsOoi, Boon S.
Embargo End Date2022-11-23
Permanent link to this recordhttp://hdl.handle.net/10754/673754
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Access RestrictionsAt the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation will become available to the public after the expiration of the embargo on 2022-11-23.
AbstractOptical wireless communication, taking advantage of the unlicensed ultraviolet-to visible wavelength region of the electromagnetic spectrum, had been coined as the next-generation wireless communication technology and holds promises to deliver a high-speed, reliable, and secured broadband experience. The push towards the optical-based medium is manifested by the demand for additional channel bandwidth to accommodate the rapid growth of the Internet-of-Things (IoT) and Internet-of-Underwater-Things (IoUT). Therefore, high-bitrate optoelectronics devices and components forming the transceiver units used in an optical wireless communication system require substantial progression to accelerate the development of this paradigm-shifting technology. In this dissertation, we demonstrated a plethora of optical detection platforms to circumvent the existing long-standing issues related to modulation bandwidth, wavelength-selectiveness, and solar-blind ultraviolet-C detection found in conventional planar silicon-based optical detectors. Herein, we presented the semipolar group-III-nitride-based micro-photodiodes for enabling up to Gbit/s optical detection in the ultraviolet-to-violet domain. The wavelength-selectiveness nature of the micro-photodiodes enabled a bitrate of up to 1.5 Gbit/s based on a power-saving on-off-keying modulation scheme. While it offers a high bitrate for the optical communication link, it restricts its detection size and angle-of-view due to the conventional resistance-capacitance and étendue limits. Therefore, we also explored using polymer-based scintillating fibers as a high-speed and near-omnidirectional optical detection platform to cater to various dynamic scenarios in optical wireless communication. The detection platform formed by the scintillating fibers enabled near-omnidirectional and large-area optical detection without sacrificing the modulation bandwidth. These investigations paved the way towards relieving the resistance-capacitance limit while addressing the pointing, acquisition, and tracking issue in underwater wireless optical communication. Subsequently, we also presented a novel wavelength-converting mechanism based on halide-perovskite nanocrystals and a conventional silicon-based platform. This demonstration addressed the lack of ultraviolet-C optical detectors in the existing market and enabled future solar-blind optical communication links. Finally, we also presented on halide-perovskite polymer-based scintillating fibers as the high-bitrate and near-omnidirectional optical detection platform. Our studies successfully addressed the existing inadequacy for high-bitrate photodetection. These works could play a significant role in progressing the technology forward, based on bottom-up material and devices innovation, to offer a reliable internet connection to the future highly interconnected society.
CitationKang, C. H. (2021). High-Bitrate Photodetection in Ultraviolet-to-Visible for Optical Wireless Communication. KAUST Research Repository. https://doi.org/10.25781/KAUST-3O4W9