Review of devices, packaging, and materials for cryogenic optoelectronics

Abstract

In this article, developments and techniques related to optical-fiber-coupled devices operating at cryogenic temperatures are reviewed. These devices include superconducting electronics and photodetectors. Superconducting circuits have a number of suitable characteristics in terms of speed and efficiency, lower power consumption, and traceability to fundamental quantum properties. Thus, applications are found in a number of technologies, such as communication and metrology. Often, the devices are coupled by an optical fiber link to an external source. A suitable design of the optical coupling at cryogenic temperatures entails considerations of electromagnetic behavior, geometry, components, material choices, and customized packaging schemes. Minimizing thermomechanical stresses and deformation is a challenge due to the extreme temperature span, from room temperature to below 10 K. Due to the thermomechanical properties at low temperatures, with high contraction and brittleness of some materials, careful design and testing is dictated for the method of mechanical attachment and alignment techniques to avoid failure. Solutions for the efficient, robust optical coupling remain a challenge for some of these devices.