R&D Towards Cryogenic Optical Links

A number of critical active and passive components of optical links have been tested at 77 K or lower temperatures, demonstrating potential development of optical links operating inside the liquid argon time projection chamber (LArTPC) detector cryostat. A ring oscillator, individual MOSFETs, and a high speed 16:1 serializer fabricated in a commercial 0.25-um silicon-on-sapphire CMOS technology continued to function from room temperature to 4.2 K, 15 K, and 77 K respectively. Three types of laser diodes lase from room temperature to 77 K. Optical fibers and optical connectors exhibited minute attenuation changes from room temperature to 77 K.