Standards activities for the next generation of Ethernet, 10 Gigabit Ethernet, are underway. Vertical Cavity Surface Emitting Lasers (VCSELs) offer significant advantages for realizing cost-effective, high speed optical data links. The progress towards achieving 10 Gb/s VCSEL-based links is reviewed.
Optical cavity light-emitting diode structures with 'buried' mirrors, and their fabrication by lateral epitaxy are described. Single-crystal, high-quality epitaxial layers are formed over substrates coated with patterned, reflective masks using liquid-phase or vapor-phase epitaxial lateral overgrowth processes. The reflecting mask acts as a backside mirror and forms an optical cavity leading to enhanced external quantum efficiencies. An AlGaAs optical cavity LED incorporating a refractory metal 'buried' mirror is assessed: a greater than 3-fold increase in output optical power is measured compared to control devices with no buried mirror. Application of the epitaxial overgrowth techniques to LED structures utilizing electron-beam deposited dielectric/semiconductor 'buried' mirrors and to other semiconductor materials, such as InGaAsSb, SiC, and ZnSe is described.