Optical Data Bus Technologies for Automotive Applications - Principles, Limits and New Trends for Vehicles and Airplanes

This paper deals with state of the art and next-decade technologies for optical data buses in automotive applications. Nowadays, optical data buses in vehicles are almost exclusively used in the infotainment domain, MOST (Media Oriented System Transport). In airplanes cosmic radiation raises new problems due to the future replacement of the metal skin by a carbon fiber one. Current data rates are in the order of 150 MBit/s. Therefore, the use of LEDs and polymer optical fibers (POF) has reached the uttermost limit of operation. For higher data rates, alternative solutions have to be found: The LED as transmitter has to be replaced by a vertical surface emitting laser (VCSEL), and plastic fiber (POF) will have to be substituted by polymer-cladded silica (PCS) fiber. The detector area of the well-known Silicon photo diodes can be reduced greatly due to smaller fiber size. As a consequence, data rates will be extended into the Gbit/s-region. This situation then enables us to use the system for sensor applications as well, including safety-relevant operations like drive by wire, break by wire and engine management, and may at last lead in the coming decades to autonomous driving.