Fibre-to-the-Chip: Development of Vertical Cavity Surface-Emitting Laser Arrays Designed for Integration with VLSI Circuits

Abstract

It is becoming evident to the builders of large digital routing and cross-connect systems that optical links provide the most efficient and scalable intra-system interconnect to the boards, shelves and bays of their equipment. There have been several research efforts around the world whose aim has been to develop what is called ‘Optoelectronic VLSI’ (OE-VLSI) technology, the intimate integration of photonic devices with VLSI electronics. Since the top-emitting devices had been fabricated as if they were to be flip-chip bonded, the fabrication sequence for the bottom-emitters was similar. This chapter describes a project whose purpose was to develop a fabrication platform that would reproducibly make high-efficiency VCSELs that easily integrate and operate with electronic circuitry and could, thus, provide fibre inter-connections directly to VLSI chips. To that end, a new design strategy was conceived, whereby VCSELs were processed with photolithographic precision and contained an intra-cavity contacted current guide and an independent optical beam guide.