  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.
