Packaging and reliability of photonic components for subscriber network systems

The packaging of photonic components employing planar lightwave circuits (PLCs, optical waveguides on a silicon substrate) and UV-curable epoxy adhesives for use in optical subscriber network systems is described. UV curable adhesives with high humidity durability and small gravity change under high temperature conditions have been developed for assembling PLC components and I/O fibers. Reliability test results on two types of photonic integrated components-an optical coupler module and wavelength-division multiplexing (WDM) optical transmitter/receiver module-are described. The modules exhibit good stability during high humidity stress tests at 70°C and 90% relative humidity or 2500-cycle temperature cycle tests between -20°C and 80°C. The dark current of the photodiode in the assembled WDM optical module showed no significant increase and was well suppressed under 1 nA during 1000 h of test, showing that the use of adhesives does not reduce the long-term reliability of active components