Novel Detection Scheme for Cryogenic Bolometers With High Sensitivity and Scalability

Cryogenic bolometers based on thin silicon nitride membranes show a very high sensitivity, which makes them ideal for ultrasensitive detector applications, particularly in the field of submillimeter-wave imaging. For that, transition-edge sensors (TESs) have been established as a viable approach toward developing multipixel sensor arrays. However, current multiplexer techniques as time- or code-division multiplexing do not scale well to multiplexing levels of several hundred detectors per channel. To achieve such a scalable readout solution, frequency-division multiplexing (FDM) would be an applicable way. For that, the temperature-sensing element of a bolometer has to be resonant or coupled to a resonance circuit, which changes its microwave behavior with the temperature of the absorber.