High-Speed and Temperature-Stable, Oxide-Confined 980-nm VCSELs for Optical Interconnects

The development of ultrahigh bit rate and temperature-stable, oxide-confined vertical-cavity surface-emitting lasers (VCSELs) operating at bit rates of 40 Gb/s and beyond is a prerequisite for solving the communication bottleneck caused by metal interconnects. Our novel design for VCSELs emitting at 980 nm includes a new active region, a λ/2-thick microcavity, and a binary bottom Bragg mirror. Error-free operation up to 49 Gb/s is observed for VCSELs slightly cooled below room temperature. At 12.5 Gb/s, error-free transmission at temperatures up to 155°C is demonstrated, as is continuous wave operation up to 200°C. Single channel data rates of 40 Gb/s are achieved up to 75°C. In addition, energy-efficient operation at 35 Gb/s at a very low bias of only 4 mA is demonstrated at a low dissipated heat-to-bit rate ratio of 233 mW/(Tb/s).