A division of focal plane (DoFP) micro grid polarizer array (MGPA) has been characterized. The MGPA under test is a commercial device available from Moxtek Inc. These wire grid style polarizers use aluminum lines fabricated on a glass substrate and have opaque regions surrounding individual pixels. Our approach to testing the MGPA has been to reimage them onto a detector by placing the MGPA at an intermediate focal plane. For the purposes of characterizing the MGPA, a high magnification reimaging optical system was assembled. The oversampled MGPA pixels were examined by using an adjustable analyzing polarizer. The effects of pixel throughput and cross talk are examined as a function of both wavelength and illumination f/#. A calibration procedure has been determined for the use of such devices. The MGPA array was also examined using a scanning electron microscope (SEM). From these SEM measurements, the pitch, fill factor, and aluminum thickness were measured. In preparation for attaching the MGPA directly to a CCD, an alignment tolerance analysis was completed. The results indicate that 0.5 μm alignment of MGPA pixel center to image sensor is required to get a system with significantly low crosstalk for useful polarization imaging.

Date Published: 8 June 2012
PDF: 9 pages
Proc. SPIE 8364, Polarization: Measurement, Analysis, and Remote Sensing X, 83640M (8 June 2012); doi: 10.1117/12.919301

Published in SPIE Proceedings Vol. 8364:
Polarization: Measurement, Analysis, and Remote Sensing X
David B. Chenault; Dennis H. Goldstein, Editor(s)