Patent ID: 7420736
Filing Date: 2008-09-02
Classification: G01J,G02B,Y10S

Abstract:
1. A method of determining a set of grating parameters for the production of a diffraction grating for a vacuum-ultraviolet spectrometer whereby the parameters are the small radius and the large radius of a toroidal grating substrate (ρ and R), the two distances (r c and r d ) of two holographic illumination points from the grating center, the angular positions (γ and δ) of the holographic illumination points to grating normals and the laser wavelength ((λ L ) for the holographic illumination and whereby the method comprises the following steps: a) establishing the wavelength range to be observed, b) determining the height and width of the detector of the spectrometer, c) determining the starting parameters for the following spectrometer parameters: j) determining the laser wavelength λ k) determining the greater radius of curvature R of the grating substrate, l) iteratively determining the smaller radius of curvature ρ of the grating substrate, the line density G at the center point of the grating and the wavelength at the detector center point, m) determining the position of the detector and the angle at which the light of the first order from the grating falls upon the detector, n) of the remaining four variables including the distances (r o) determining the minimum of the magnitude Δλ iteratively as a function of the three remaining variables (spacings r