We investigate the use of low-threshold 980-nm vertical-cavity surface-emitting lasers for free-space optical interconnects. The vertical-cavity surface-emitting lasers and backilluminated detectors are monolithically integrated with microlenses on the back sides of the growth substrates to eliminate the necessity of external optics. With a channel pitch of 250 μm, an interconnect length between boards of the order of 5 to 10 mm with a ∓50-μm lateral alignment tolerance can be achieved without external relay optics. The complete link is modeled to predict the system’s efficiency and maximum bit rate. Data transmission at 500 Mbits/s per channel is demonstrated. The data rate was limited by parasitics, not the inherent bandwidth of the laser diodes.
© 1998 Optical Society of America
(140.3460) Lasers and laser optics : Lasers
(200.4650) Optics in computing : Optical interconnects
(220.3630) Optical design and fabrication : Lenses
(350.3950) Other areas of optics : Micro-optics
Eva M. Strzelecka, Duane A. Louderback, Brian J. Thibeault, Geoff B. Thompson, Kent Bertilsson, and Larry A. Coldren, "Parallel Free-Space Optical Interconnect Based on Arrays of Vertical-Cavity Lasers and Detectors with Monolithic Microlenses," Appl. Opt. 37, 2811-2821 (1998)