<title>VCSEL devices and packaging</title>

Abstract

Over the last few years, Motorola has been applying a different kind of semiconductor laser technology to a family of datalink and discrete products. The laser technology is commonly referred to as Vertical Cavity Surface Emitting Lasers (VCSELs). This technology is now emerging from advanced development and research laboratories into the market place, and there is a number of introductory texts, inaddition to journal articles that describe the technology [1]. Motorola, has chosen the VCSEL technology to be the back-bone of it's optical program and has developed products such as the OPTOBUSTM datalink [1,2,3], which interconnects arrays of VCSELs inside a small, compact module via parallel fiber ribbon to receiver modules. As an extension to this technology, Motorola has designed new and novel ways to package the VCSELs. This paper will detail, inaddition to the packaging used in OPTOBUSTM, two approaches to discrete VCSEL packaging that are commercially competitive; the flip-chip and the angled angle TO-can. The essence of both these package designs is what is usually termed as 'auto-power control' (APC). This allows a feedback mechanism to feedback a signal to the laser, to control or change its output power level with respect to system conditions. Usually, this is accomplished by back facet monitor photodetectors in conventional edge emitting laser systems. As the VCSEL does not have facets, alternative solutions have to developed; the flip-chip and angled TO-can are shown to be good candidate.