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High power VCSEL (Vertical-Cavity Surface-Emitting Lasers) as light sources for free space optical communications have been developed. These VCSEL devices have 4, 9, or 16 simultaneously driven spots-similar to a single spot VCSEL and have a single cone-shaped Far Field Pattern (FFP) under high optical output power operations at 10, 20 and 40mW. Since the multi spots are driven simultaneously, these devices have a high optical output power even if the optical output power from each spot is small. As a result, the Mean Time To Failure (MTTF) obtained from a 4 spot multi-mode 850nm VCSEL array is well over 1,000,000 hrs at 70°C under a 10mW operation.The VCSEL arrays also show a wide-open 2.5Gbps eye diagram at standard driving conditions-more than sufficient for optical free space communications such as optical wireless HDTV transmission systems. The simultaneously driven 9 and 16 spot multi-mode 850nm VCSEL arrays also show similar wide-open 2.5Gbps eye diagrams under standard driving conditions.Simultaneously driven multi spot VCSEL arrays are useful as light sources for Free Space Optics (FSO) because of their high speed modulation and high reliability under high optical output power operation.

The authors have shown complete polarization control of a 12×8-bit matrix-addressed oxide-confined vertical-cavity surface-emitting laser (VCSEL) array, which has an unstrained active region emitting at 780 nm. By using a combination of an elliptical-shaped post structure fabricated on misoriented substrate and upper p-side metal lines elongated in the substrate off-direction, we observed complete polarization pinning in an index-guide type array device. All of the VCSELs in this array lased in a fundamental transverse mode and linearly polarized along the <01-1> direction.

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