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Advances in long-wavelength single-mode VCSELs and packaging approaches for single-mode fiber applications

Within the past year there have been significant improvements in the performance of 1300-1550 nm vertical-cavity surface-emitting lasers (VCSELs), especially with desirable all-lattice matched structures. Perhaps the most promising of these is formed in a single epitaxial growth on InP substrates. Much like their shorter wavelength (850-980 nm) predecessors, grown with all-lattice matched materials on GaAs substrates, these devices promise to provide low-cost, highly manufacturable and reliable sources for fiber optic links, but now in the longer wavelength range, where longer distance, higher data rate transmission is possible. However, such devices still need to be packaged with single-mode fiber to fully realize this potential, and this greatly complicates the nature of the packaging problem, as compared to the earlier low-cost 850 nm gigabit Ethernet modules that used multimode fiber. In this paper we will first review the advances that have occurred with single-crystal VCSELs grown completely lattice matched from various III-V alloys on InP, and we will then explore possible techniques to provide low-cost, high-performance packaging to single-mode fiber.