Dense Polarization-Keyed Fiber Optic Communication System

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

Full Exploitation of Polarization Modulation for Increasing Data Speed in an Integrated Fiber Optic Communication System Optical fibers form the workhorse of the telecommunications industry today. Their information carrying capacity has risen spectacularly. Even so, demand for higher capacity will continue at an increasingly rapid rate due to the rise of cloud computing, distributed data centers, and the Internet of Things (IoT). The objective of this proposal is to address such a need by fully exploiting the polarization property of light for information transmission that can significantly surpass the capability of the technologies employed in current optical fiber communication systems. The outcomes of the research are expected to give a significant boost to the channel capacity in a single fiber without the need of fiber infrastructure upgrade, hence pushing the capacity limit of existing optical fiber networks. The proposed work is compatible with current and future fiber-optic technologies, making it readily deployable and future-proof. Aside from technology advancement, the project offers undergraduate and graduate students the opportunity to gain practical as well as state-of-the-art technology experiences that are indispensable for the telecommunication industry. The proposal will help train students and equip them with the knowledge of technology and its commercialization leading to creation of new businesses. In turn, this will increase the competitive edge of the United States. Polarization of light has been used in optical communications for carrying or switching information. Current applications mostly focus on utilizing the two independent polarization channels to double the data transmission capacity of a single-mode optical fiber. The goal of this research is to significantly increase the capacity by exploiting the very large number of possible states of polarization (SOPs) to encode information. This is accomplished by maximizing the number of distinguishable SOPs with the use of optimal quantum receivers for SOP estimation and a machine-learning-based optimal polarization modulation format in an integrated fiber optic communication system. The research will explore this capacity in single-mode fibers through theory as well as experimental results. Research tasks will include the design of optimal polarization receivers for the optical communication link, the combination of polarization shift keying (POLSK) with phase-shift keying (PSK) and quadrature amplitude modulation (QAM), deep neural network-based optimizations for the polarization modulation format, and an experimental testbed incorporating the optimal modulation and detection for the entire optical link composed of the transmitter, channel and receiver. Specifically, the optimal polarization modulation format obtained by machine learning over the integrated transmitter-channel-receiver architecture will give new insights to system optimization that incorporates data-driven information on the optical link impairments. This is in contrast to the conventional approach to optimizing the components of the communication system individually at the expense of optimality of the composite system. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.