Flip-chip bonded VCSELs with integrated microlenses for free-space optical interconnects

For massively parallel interconnects between data processors, or between memory elements and processors, free-space optical techniques have been proposed for some time. In recent years the use of large arrays of vertical-cavity surface-emitting-lasers (VCLEELs) and photodetectors flip-chip bonded to electronic processing or memory chips has gained acceptance as a very promising technique to accomplish the desired interconnects. The flip-chip bonding provides a simple way of incorporating 3-D electrical interconnects to the small contacts of densely arrayed VCSELs and detectors without adding undo capacitance to limit speed or produce crosstalk