Regensburg 2007 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 19: Symposium “Terahertz Detectors”
TT 19.6: Talk
Wednesday, March 28, 2007, 17:00–17:30, H20
FIR Detectors for Herschel and SOFIA — •Albrecht Poglitsch1, P. Agnese2, L. Barl1, N. Billot3, O. Boulade3, L. Duband4, U. Groezinger5, R. Hoenle1, and P. Merken6 — 1MPE, Garching, Germany — 2LETI, Grenoble, France — 3CEA, Saclay, France — 4CEA, Grenoble, France — 5MPIA, Heidelberg, Germany — 6IMEC, Leuven, Belgium
We report the development of new, large format detectors for the 50 - 200 micron wavelength range for use in cameras and spectrometers.
The lowest detector noise, needed for background-noise limted spectroscopy, is achieved with Ge:Ga photoconductor arrays. These arrays are based on individual Ge:Ga detectors contained in integrating cavities. In order to detect light at wavelengths >120 microns, uniaxial stress is applied to each detector crystal. In combination with their cryogenic readout circuits, these detectors reach effective quantum efficiencies of >30% under representative background conditions, or NEPs down into the 10^-18 W/sqrt(Hz) range.
For the higher background experienced in photometry we have developed 3-sides buttable bolometer arrays. They represent the first monolithic filled arrays of bolometers with a cold multiplexed readout. They have been optimised for both, high FIR absorption efficiency and minimum cross section to cosmic rays for operation in a space environment. The bolometers, working at a temperature of 300mK with a dedicated 3He cooler, have an NEP of ~10^-16 W/sqrt(Hz) and a post-detection bandwidth of 4 to 5 Hz.