Passive fibre interfacing to optoelectronic devices using hybrid micropackaging

Low cost, passive alignment techniques are key to the widespread deployment of optoelectronic devices; assembly and packaging costs are currently dominated by the accurate positioning and fixing of the optical fibre in a critical alignment to the optoelectronic chip. GMMT Caswell are using microetched silicon components for chip carriers with V-grooves for passive fibre positioning and flip-chip solder bump technology for chip positioning and electrical interfacing. The extension of this technology from multimode fibre to the tighter tolerances required for monomode fibre is discussed below, for interfacing to discrete and array LEDs, detectors, lasers and optoelectronic integrated circuits (OEICs). The fabrication and performance of a compact hybrid transceiver multi-chip module for burst mode operation in optical backplane applications in avionics and datacomms is described. This unit employs a silicon baseplate to interface the laser (selected for wide operating temperature range) to a 50/125 μm output fibre, attaining a coupling efficiency of ~20%, which is comparable to that achieved by active alignment. The input fibre is terminated in a 45° mirror to direct light to the PIN detector mounted in a recess in the silicon baseplate. The module, measuring 15 mm by 25 mm and only 3 mm high, incorporates a laser driver integrated circuit and custom receiver chip for 500 Mbit/s operation over a polymer waveguide backplane