Built in Test (BIT) Capability for Multi-Mode (MM) Fiber Data Networks

ABSTRACT:Fiber optic network connections onboard airborne platforms must operate in extreme environmental conditions. As a result, these fibers degrade over time leading to faults and reduced performance. A Built-In Test (BIT) capability for the fiber optic transceivers in the embedded systems is required to monitor the fiber optic health and provide diagnostics for rapid repair in the event of failure. Crossfield proposes a multi-protocol VPX Switch with embedded Optical Time Domain Reflectometer (eOTDR) with integrated BIT. The switch will provide a standards-based optical backplane, interconnecting VPX processor and data acquisition modules and sensor payloads at serial data rates up to 56 Gb/s, with a near term upgrade to 100 Gb/s. Crossfield proposes to use eOTDR technology developed at Sandia National Laboratories in the switch to perform BIT on each transmit channel. This methodology enables the VCSELs in a transmitter optical engine to operate as both an optical impulse generator and backscatter detector, the two key electro-optical functions required to implement an OTDR. Crossfield will implement the eOTDR functions in an integrated circuit, for integration into the transmitter optical engine along with the VCSELs and VCSEL drivers.BENEFIT:An embedded OTDR chip will provide a important fiber optic diagnostic tool at a small incremental cost to commercial transceivers. A smart transceiver with fiber optic BIT will enable IT professionals to rapidly diagnose failed optical links in commercial data centers.