High speed transmission over Multimode Fiber with direct modulated single-mode VCSEL

In current data centers, most of optical links are based on vertical-cavity surface-emitting lasers (VCSEL) operating at 850 nm over multimode optical fiber. The demand for increasing data rates implies a decrease of link reach length. For example, at current standards 25-Gbit/s-links are limited to 100 m. In this paper, we still demonstrate successful transmission at 25 Gbit/s over 1 km of multi-mode fiber by using an optimized VCSEL structure with a single primary mode. This indicates that the relative low cost VCSEL-technology is still capable to fulfill the future bandwidth requirements in data centers. Furthermore this new technology has the capability to be an option for the future in-house distribution networks or to connect the end-user within the last mile.