Evaluation of Submillimeter/Terahertz Camera Performance With the Cryogenic Multi-Channel Read Out System

The purpose of our development is to realize the terahertz camera with superconducting tunnel junction detectors and cryogenic integrated circuits made of gallium-arsenide junction field-effect transistors (GaAs-JFET). This paper presents the first demonstration of such system. First, we have combined cryogenic charge integrating amplifiers made of GaAs-JFETs with the superconductor-insulator-superconductor (SIS) photon detectors at 0.5 K, and the detector current was successfully read out by the cryogenic amplifiers. Secondly, we have demonstrated an operation of a 32-channel multi-chip module all made of the GaAs-JFET circuits. The module has 32-channel detector input ports and two read out multiplexers for fast sampling. The power dissipation is about 350 μW . Using 910 kΩ resistors in place of detectors we measured output voltage noise of 3 mV_rms with a charge integration time of 1 ms,. From these results, we have proven the terahertz camera technologies using SIS photon detectors and cryogenic read out electronics with the noise equivalent power (NEP) of 3.8 × 10^-15 W/Hz^0.5 and 1 kHz frame rate.