Polarization-Sensitive Imaging Arrays

Two different monolithic imaging arrays have been developed that image polarization as well as intensity at near-millimeter wavelengths. One array is a row of linearly polarized bow-tie antennas that lean alternately left and right. This array has measured the polarization with a precision of 7 arc-minutes, and has demonstrated diffraction-limited resolution of a 20° step change in polarization. The other array is a row of circularly polarized equiangular spiral antennas, alternately spiraling clockwise and counterclockwise, that respond to left-handed and right-handed circular polarization.