BERLIN -- VI Systems GmbH and the Department of Electrical and Computer Engineering at the University of Illinois, USA demonstrated jointly at the Photonics West Conference a novel Single Mode Photonic Crystal VCSEL (vertical cavity surface emitting laser). The photonic crystal (PC) VCSEL is manufactured from a proprietary VI System’s wafer which was processed at the University of Illinois at Urbana-Champaign with a defined photolithographic pattern of holes in the top mirror. This process results in a single mode emission of the VCSEL at 850nm wavelength.PC VCSEL operating at low current density of 5.4 kA / cm2 enables -3dB bandwidth of 18GHz. Error free optical data transmission at 25 Gbit/s over 1-km OM4 multimode fiber has been realized at 1 km distances at very low received power of only 70 µW at the Department of Solid State Physics at the Technical University of Berlin, Germany, with a high speed photoreceiver module from VI Systems GmbH.Single-mode VCSELs extend the reach over multimode fiber by eliminating the impact of chromatic dispersion of glass at 850 nm wavelength, which is particularly important for ultrahigh transmission bit rates within the next generation of datacom and computercom standards. VI Systems GmbH