Abstract

Consumers of optical storage products strongly desire optical disk and tape drives with high data transfer rate for many applications including: multimedia, archival storage, software distribution and reconnaissance. In order to increase the data rate at which information is read from or written to optical storage media, parallel multi-channel systems have been proposed or demonstrated [1,2]. Our approach aims to increase data transfer rates by more than an order of magnitude through multi-channel drives having minimal effect on the hardware and on the cost of the product. The emergence of vertical-cavity surface-emitting laser arrays (Lase-Arrays™), [3,4] enables unique multi-channel configurations for high-data-rate parallel optical reading and writing of information. Lase-Arrays represent a new class of semiconductor laser diodes which, unlike conventional edge-emitting semiconductor laser diodes, are directly "printed" in ID and 2D arrays using standard III-V compound semiconductor circuit fabrication techniques. Fig. la shows a photograph of a portion of a 2x32 Lase-Array. Lase-Arrays emit light perpendicular to the plane of the wafer, as compared to edge-emitting laser diodes which emit light in the plane of the wafer. Also, unlike edge-emitters, Lase-Arrays have circularly-symmetric, aberration-free beams. Arrays of microlenses are straightforwardly integrated to Lase-Arrays (Fig. la) to enable optical mappings which are impossible with conventional macroscopic optics, for example, mapping an array of widely-spaced, low-fill-factor lasers to an array of closely-spaced, densely-packed spots. This mapping is ideal for multi-channel optical storage applications using either disks or tape as the storage medium.

© 1994 Optical Society of America