Abstract

A Josephson sampler basically consists of a sampling gate and a sampling-pulse generator. As Fig. 1 shows, the sampling gate is a Josephson junction to which the signal, the sampling pulse and a dc bias are coupled either directly, as in the figure, or via control lines. The dc bias is adjusted such that the sum of the three inputs just reaches the threshold of the gate, the switching of which is detected by an external voltage dector. The dc bias is adjusted automatically with an external feedback loop. If the sampling pulse is moved along the signal by means of a variable time delay, then the dc bias current as a function of the delay will yield a replica of the signal.

© 1985 Optical Society of America