Horn Coupled Multichroic Polarimeters for the Atacama Cosmology   Telescope Polarization Experiment
  Multichroic polarization sensitive detectors enable increased sensitivity and spectral coverage for observations of the Cosmic Microwave Background (CMB). An array optimized for dual frequency detectors can provide 1.7 times gain in sensitivity compared to a single frequency array. We present the design and measurements of horn coupled multichroic polarimeters encompassing the 90 and 150 GHz frequency bands and discuss our plans to field an array of these detectors as part of the ACTPol project. 
Rahul Datta, Johannes Hubmayr, Charles Munson, Jason Austermann, James   Beall, Dan Becker, Hsiao-Mei Cho, Nils Halverson, G...
astro-ph.IM