An integrated CMOS (Complementary Metal-Oxide-Semiconductor)-compatibl
e optical detector for liquid-helium-temperature LHT (4.2K) operation
is presented. The optical detector, which responds to 0.768- and 1.1-m
u m wavelength light sources, is built in the n-well of a 0.7 mu m CMO
S integrated circuit technology. The optical detection is based on the
photogeneration of carriers in the frozen n-well that changes its out
put resistance at a ratio of 1.79 M Omega per mW of optical power. The
cryo-optical system has been tested with and without a built-in pream
plification, and has been proved to respond to 50 MHz-optical pulses.
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