EXTREME-ULTRAVIOLET POLARIZATION AND FILTERING WITH GOLD TRANSMISSIONGRATINGS

The polarization and transmission characteristics of freestanding gold transmission gratings, with 200-nm periods, for extreme-ultraviolet ( EUV) radiation (l < 200 nm) have been measured. We find that EUV trans mission through the gratings is dominated by the waveguide characteris tics of the gratings and that polarization efficiencies of 90% for wav elengths of 121.6 nm are achievable. Both the EUV polarization and tra nsmission properties are in good agreement with a complete vector, num erical solution of Maxwell's equations. The fraction of open area to t otal area of the grating has been measured using a 10-keV proton beam and was found to be in good agreement with the microscopic slit and wi re dimensions that were obtained by scanning electron microscopy. The use of these gratings for particle measurements in the presence of int ense EUV radiation is briefly discussed.