Optical characterization of the BICEP array 150 and 220/270GHz CMB polarimeters in the 2026 season
BICEP Array (BA) is the current-generation instrument in the BICEP series of small-aperture, on-axis refracting telescopes at the South Pole, designed to constrain the tensor-to-scalar ratio $r$ through degree-scale measurements of B-mode polarization in the cosmic microwave background (CMB). As BA pushes to deeper sen...