Alignment and polarization sensitivity study for the Cassini composite infrared spectrometer (CIRS) far-infrared (FIR) interferometer

摘要

Abstract: The Composite InfraRed Spectrometer (CIRS) instrument flying on the Cassini spacecraft to Saturn is a cryogenic spectrometer with far-infrared (FIR) and mid-infrared channels. The CIRS FIR channel is a polarization interferometer that contains three polarizing grid components. These components are an input polarizer, a polarizing beamsplitter, and an output polarizer/analyzer. They consist of a 1.5 micron ($mu@m) thick mylar substrate with 2 $mu@m wide copper wires, with 2 $mu@m spacing (4 $mu@m pitch) photolithographically deposited on the substrate. This paper details the polarization sensitivity studies performed on the output polarizer/analyzer, and the alignment sensitivity studies performed on the input polarizer and beamsplitter components in the FIR interferometer.!10