Hybrid Analog-Digital Fiber Optic Network for Aircraft Communication and Control

Fiber optic networks are currently deployed throughout an aircraft to allow communication between the various systems on-board. Fibers offer the advantage of reduced weight, higher bandwidth and immunity to electromagnetic interference over traditional coaxial cabling. Typically, one network carries digital data from one on-board system to another, while another takes analog data for electronic warfare applications received from an external source and sends it to a central on-board system [1]. In order to reduce the complexity and maintenance of multiple fiber networks, it would be advantageous to use a single fiber network over which both types of signals could travel. Previous work has looked at combining both analog and digital signals over the same fiber [2, 3]. However these demonstrations required the analog signal to operate at a frequency beyond that of the digital data. In this paper we demonstrate a system to transmit both analog and digital signals within the same frequency bands over the same fiber network with minimal degradation of either signal due to interference from the other.