Packaging of fiber-coupled module for Josephson Junction Array voltage standards

This paper describes issues related to the packaging of a fiber coupled optoelectronic module intended as a current source for pulse-driven Josephson arrays, operating at cryogenic temperatures. The module consists of flip-chip bonded photodiodes on a silicon carrier with adhesively bonded optical fiber components in a compact package. Optical and thermomechanical simulations were performed, showing that the needed functionality can be achieved, with optical coupling efficiency above 90% for fiber-chip misalignments up to 40 mu m, and that the thermomechanical stresses can be reduced by controlling of the adhesive bonding process.