We present an improved version of a linear low-noise optical coupler having
differential input and capable of driving a twisted cable to long distance
s, avoiding ground loops and electromagnetic interference. Owing to device
optimization, this circuit version is able to be fast. Its frequency bandwi
dth is about 900 kHz, more than ten times larger than our previous implemen
tation. The optical coupler presented is therefore suitable to be used with
most of the applications with cryogenic detectors. (C) 2000 Elsevier Scien
ce B.V. All rights reserved.