The Wide-field Infrared Survey Explorer (WISE) beamsplitter assembly

The design, fabrication and testing of the BeamSplitter Assembly (BSA) of the Wide-field Infrared Survey Explorer (WISE) instrument are discussed in the paper. The BSA splits the WISE telescope optical output beam into 4 spectral wavelength bands: 2.8-3.8, 4.1-5.2, 7.5-16.5, and 20-26 μm. The BSA also provides focus adjustments to focus the WISE instrument prior to launch. The methods used to focus WISE are also discussed in this paper. Funding for and management of the WISE program were provided by the NASA Jet Propulsion Laboratory.