High data rates and immunity from electromagnetic interference are bringing fiberoptic communications into the automobile, via the so-called MOST (Media Oriented Systems Transport) bus; the result will be intravehicle communications networks to handle everything from on-board computing to DVD signals (see www.laserfocusworld.com/articles/250384). Polymer optical fibers paired with light-emitting diodes (LEDs) are usually chosen, but these fibers are limited to temperatures below 85°C, bending radii above 25 mm, and medium data rates.
Multicore glass optical fibers developed by Schott (Mainz, Germany) are designed to push past these restrictions, allowing the use of fiber for active safety applications in the engine compartment, such as tying together cameras or radar systems that are installed in the bumper for precrash analysis of traffic. The fibers have hot-fused end surfaces, single-fiber diameters of 53 µm, and withstand 125°C, bend to a 5-mm radius, and transmit at 1 Gbit/s, allowing real-time transmission without data compression. The multicore fibers are paired with near-IR vertical-cavity surface-emitting lasers, which can be modulated at much higher rates than LEDs, but whose wavelengths are not transmitted well by polymer fibers. Contact Kate Pepler at [email protected].