Development of SQUID Amplifier and AC-biased Bolometer for Detection of Sub-mm Radiation
Jari S Penttilä, Antti Virtanen, M. R. Nevala, Kimmo M. Kinnunen, Arttu R. Luukanen, Juha Hassel, M. Kiviranta, P. Helistö, Ilari J. Maasilta, Heikki Seppä
SRON is developing the Frequency Domain Multiplexing (FDM) read-out and the ultra low NEP TES bolometers array for the infra-red spectrometer SAFARI on board of the Japanese space mission SPICA. The FDM prototype of the instrument requires critical and complex optimizations. For single pixel characterization under AC bias we are developing a simple FDM system working in the frequency range from 1 to 5 MHz, based on the open loop read-out of a linearized two-stage SQUID amplifier and high Q lithographic LC resonators. We describe the details of the experimental set-up required to achieve low power loading (<1 fW) and low noise ( NEP∼10−19W/Hz ) in the TES bolometers. We conclude the paper by comparing the performance of a 4×10−19W/Hz TES bolometer measured under DC and AC bias.