Hans-Peter Huber

Optical data buses for automotive applications

Optical data links and bus systems are becoming increasingly attractive for automobiles. In 1998, a first optical data bus system, based on polymer optical fibers and visible light-emitting diodes was introduced in Mercedes-Benz cars to interconnect information and entertainment devices within the passenger compartment. Since 2002, media-oriented system transport (MOST) is the standard for an optical infotainment data bus system in the automotive industry. However, with increasing demands on network flexibility, robustness, safety-relevant functions, and data rate, the currently used technologies reach their limit. A new physical layer, based on 200-/spl mu/m polymer-cladded silica fibers and infrared-emitting vertical-cavity surface-emitting lasers, is a promising solution. This paper provides an overview about the state-of-the-art physical layer of standard MOST data bus systems, shows its limitations, and presents new optical-physical-layer concepts for next-generation data bus systems in cars.

10 Gb/s data transmission with TO-packaged multimode GaAs VCSELs over 1 m long polymer waveguides for optical backplane applications

Abstract TO-packaged GaAs vertical-cavity surface-emitting lasers (VCSELs) are being investigated for high-bit-rate data transmission over 103 cm of a 250×200 μm 2 core size polymer-based optical waveguide to be employed in optical backplanes. The bit-error rates for 5 and 10 Gb/s transmission over the waveguides incorporating 45° deflection mirrors are better than 10−12. For the first time, the measured bandwidth-length-product for a polymer-based optical backplane exceeds 10 GHz × m .

Polymer waveguides for 100-cm (40) optical backplanes

Optical backplanes are attractive components for systems with high data rates between subsystems and a large number of interconnects. An optical backplane which uses multimode polymer waveguides was originally developed for avionic applications but can be used in telecom switching systems as well. For transmission distances in the range of 100cm and data rates up to 10Gbps, the modal dispersion can be negelected. The waveguides are fabricated on large substrates (aluminum, FR4 and others) by a direct writing technique. Splitters and couplers can be fabricated with the same technique. The waveguides have a low loss (0.04dB/cm) and high temperature stability (up to 250°C) and are used with 840nm vertical cavity lasers. The waveguide cross section can be chosen between approx. 250μm x 250μm and 50μm x 50μm. We have successfully transmitted up to 10Gbit/s over multimode polymer waveguides with lengths of 100cm. A free space, expanded beam coupling is used for the board-backplane transition, resulting in high alignment tolerances. The overall insertion loss for a backplane connection is typically between 2 and 8 dB, depending on waveguide length, radius of curvature, number of waveguide crossings etc. A typical transceiver power budget of 15-20dB allows the integration of star couplers with up to 16 ports. Several test systems with different interconnection schemes have been realized and tested. Tests include mechanical stability (vibration), thermal stability (cycles, shocks and accelerated aging) and gamma irradiation as well as optical power levels, signal integrity and bit error rates.

Planar star couplers for 200 /spl mu/m multimode PCS fibers

We have investigated the design and the fabrication of planar transmissive and reflective star couplers for 200 /spl mu/ polymer clad silica (PCS) fibres. We propose the design of potential low-cost planar optical star couplers and demonstrate prototypes with good optical performance.