Cryogenic SiGe integrated circuits for superconducting nanowire single photon detector readout

Abstract

There is a growing interest in developing systems employing large arrays of SNSPDs. To make such instruments practical, it is desirable to perform signal processing before transporting the detector outputs to room temperature. We present a cryogenic eight-channel pixel combiner circuit designed to amplify, digitize, edge detect, and combine the output signals of an array of eight SNSPDs. The circuit has been fabricated and measurement results agree well with expectation. The paper will conclude with a summary of ongoing work and future directions.

A Wideband Cryogenic Readout Amplifier with Temperature-Insensitive Gain for SNSPD

“…In contrast, when an incident photon is absorbed by the SNSPD, the switch is opened, pushing the current into the parallel resistor R P . Accordingly, a pulse voltage signal, typically with several hundred microvolts amplitude, is generated [ 22 ], as shown in Figure 3 b. Normally, its rising time is around 200 ps, while its falling time ranges from 10 to 60 ns.…”