Polarization enhancing optical system for a high-resolution VUV spectroscopic facility at a synchrotron light source

A reflecting optical system designed as part of a new high-resolution VUV spectrometer facility at the SURF II light source at the National Bureau of Standards is described. The system employs three cylindrical mirrors to focus an image of the storage ring source on the entrance slit of a 6.65-m vacuum spectrometer located 10 m from the source point. Image properties and focusing techniques are demonstrated with ray-trace diagrams and visible light images. Reflectance values in the VUV are large and the mirrors are oriented so that the electric vector of horizontally polarized synchrotron radiation is always perpendicular to the plane of incidence. Depending on the wavelength and coating material chosen, large differences in the transmittance for the s and p polarization components of the light beam are possible, with polarization purities greater than 95 percent expected throughout the 500-2000 A range and values as high as 99 percent possible for wavelengths over 1000 A.