Packaging aspects of the LitebusTM paralleloptoelectronic module

摘要

The Litebus module is an optoelectronic transceiver and the keycomponent in a parallel fiber optic data link. The module is designed toextend computer-to-computer communications to data rates and linkdistances beyond those achievable in copper at comparable cost. Atransceiver configuration was selected to keep the module's size compact(45 mm×32 mm× 9.8 mm) and to facilitate the integration ofan IEC Class 1 laser safety strategy. The Litebus module consists ofvarious packaging components and both CMOS and optoelectronic dies. Itis designed to accept a single connector, having one receive and onetransmit section, that is mounted on the end of a dual 12 channel fiberoptic ribbon cable. Channel-to-channel spacing is 250 μm throughoutand standard multimode fiber is used. The transmitter consists of aVCSEL (Vertical Cavity Surface Emitting Laser) source having awavelength of 850 nm. The receiver consists of a transimpedanceamplifier with integrated Metal-Semiconductor-Metal (MSM) detector. Themodule's transmit and receive sections were designed to operate at datarates greater than 1.25 Gb/s (gigabits per second) per channel, yieldinga maximum aggregate data rate in excess of 15 Gb/s. In one mode ofoperation, byte-wide data is simultaneously transmitted from andreceived by the module at 1.25 GB/s (gigabytes per second), with thefour remaining channels on each side being assigned to user-definedoverhead functions. The maximum cable length is 400 m in asynchronousmode and 200 m in synchronous mode