Large Bandwidth, Small Current Density, and Temperature Stable 980-nm VCSELs

A low-cost method to adjust the mirror reflectivity of vertical-cavity surface-emitting lasers (VCSELs) helps to optimize the cavity photon lifetime. The joint variation of photon lifetime and the oxide aperture diameter of our 980-nm VCSELs allows optimization procedures between the laser parameters. A new indicator helps to judge the optimum mirror reflectivity to enable increased bit rates in concert with reduced energy consumption, as well as temperature stability, and a smaller bias current density. Error-free back-to-back data transmission at 50 Gb/s over a wide temperature range from 25 °C to 75 °C for completely unchanged driving conditions is presented amongst other progress, including a 400-fJ/b data transmission energy efficiency at 50 Gb/s.