High density interleaved VCSEL-RCPD arrays for optical information processing

Vertical-cavity surface-emitting lasers (VCSELs) are uniquely suited for massively parallel interconnects and scannerless imaging applications due to their small size, high efficiency and amiability to formation of high-density 2-dimensional arrays. We have successfully fabricated 4096 element arrays (64×64) containing alternating rows of selectively-oxidized 850 nm VCSELs and resonant-cavity photodetectors (RCPDs) on a 55 micron pitch monolithically integrated on semi-insulating GaAs substrates. We employ a matrix addressable architecture to reduce the input and output electrical connections to the array, where all the VCSELs (or RCPDs) in each row are connected by a common metal trace at the base of their mesas. The columns are connected by metal traces that bridge from mesa top to mesa top, connecting every other row (i.e., only VCSELs or only RCPDs). The design, fabrication and performance of these arrays is discussed.