VLS Grating for X-Ray Optics as Fabricated by e-beam Nanolithography with Optically Confirmed Exponential Line-density Variation

We report the development of a large-area plane Varied Line-Space grating with line density varying exponentially along the grating surface roughly from 160 to 560 mm –1 . The grating was produced using e-beam lithography with original square-stamp beam profile and is intended for an innovative high-resolution single-component grazing-incidence monochromator, in which wavelength scanning is achieved simply by linear movement of the grating along its surface. For a grating width of 60 mm, the first-order operating spectral range is 9–20 nm. Optical measurements of the line density-vs-coordinate dependence reveal perfect match between the fabricated and intended by the design density dependences.