Design and Fabrication of Two-Dimensional Superconducting Bolometer Arrays

Large format, two dimensional arrays of close-packed bolometers will enable submillimeter cameras and spectrometers to obtain images and spectra orders of magnitude faster than present instruments. The South Pole Imaging Fabry-Perot Interferometer (SPIFI) for the AST/RO observatory and the Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory will employ a large-format, two-dimensional, close-packed bolometer arrays. Both these instruments are imaging Fabry-Perot spectrometers operating at wavelengths between 100mum and 700mum. The array format is 16x32 pixels, using a 32-element multiplexer developed in part for this purpose. The low backgrounds achieved in spectroscopy require very sensitive detectors with NEPs of order 5.10(-18) WNHz. Superconducting detectors can be close-packed using the Pop-Up Detector (PUD) format, and SQUID multiplexers operating at the detector bas temperature can be intimately coupled to them. We have fabricated and assembled an engineering model array of close-packed bolometers with a multiplexed readout that features a very compact, modular approach for large format arrays.