Recent progress in short-wavelength VCSEL-based optical interconnections

We report on recent progress in the design and application of vertical-cavity surface-emitting lasers (VCSELs) for optical interconnect applications in the 850 nm emission wavelength regime. Ongoing work toward parallel optical interconnect modules with channel data rates of 10 Gbit/s is reviewed and performance results of flip-chip integrated two-dimensional VCSEL arrays are presented. 10 Gbit/s speed as well as low thermal resistance of the lasers has been achieved. As a possible alternative to graded-index multimode fibers, we show 10 Gbit/s data transmission over 100 m length of a novel, entirely undoped multimode photonic crystal fiber. The use of VCSELs with output powers in the 10 mW range is demonstrated in a 16-channel free-space optical (FSO) module and VCSELs with even higher output power are shown to provide possible FSO connectivity up to data rates of 2.5 Gbit/s.