27 April 1988 FIRAS Wire Grid Characterization Techniques
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Characterization techniques used to verify the quality and spectral performance of the large free standing wire grid polarizing beamsplitters and input/output polarizers used in the Far Infrared Absolute Spectrophotometer (FIRAS) are presented. The clear aperture of these grids is lined with 20.8 micron diameter gold coated tungsten wire, spaced 33 microns apart. The grid characteristics measured throughout fabrication and space flight qualification are the center to center wire spacing and wire plane flatness. Ideally, the wire grids should produce coherent wavefronts with equal reflectance and transmittance properties. When the spacing is inconsistent, these wavefront intensities are unequal, thus decreasing the efficiency of the grids and reducing the output signal of the FIRAS. The magnitude of the output interferogram is also reduced by incoherence in the interfering wave fronts caused by uneven flatness.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Richard D. Barney, Richard D. Barney, Thomas J. Magner, Thomas J. Magner, "FIRAS Wire Grid Characterization Techniques", Proc. SPIE 0973, Cryogenic Optical Systems and Instruments III, (27 April 1988); doi: 10.1117/12.948357; https://doi.org/10.1117/12.948357

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