Micropolarizer array for infrared imaging polarimetry

The design and fabrication of a micropolarizer array for imaging polarimetr y is described for the 3-5-mu m-wavelength region. Each micropolarizer cons ists of a 475-nm-period Mo wire grid in a 16 mu m x 16 mu m aperture. Inter ference lithography is used to generate the small grating features through an etch mask layer. Arrays of 256 x 256 micropolarizers at three distinct a ngular orientations have been fabricated that permit the measurement of the first three Stokes vector components in each pixel of an imaging polarimet er. An imaging system composed of a micropolarizer array integrated directl y onto a focal plane array has been assembled, and initial testing has been performed. (C) 1999 Optical Society of America [S0740-3232(99)01905-5].