DIFFRACTION GRATING AND METHOD OF ITS MANUFACTURE Russian patent published in 2004 - IPC

FIELD: optics.

SUBSTANCE: diffraction grating is intended for building diffraction images of non-point non-monochromatic light source. Diameter of sphere described around light source equals to D and located at distance x_s mm from surface of diffraction grating. Lines of diffraction grating are drawn in two mutually perpendicular directions. Limit of acceptable angle deviation between lines applied at different directions from 90 deg angle equals to 10 deg. Spatial frequency of lines at each direction does not exceed value f=2D/(λx_s), where λ=0,00038. Method of manufacturing diffraction grating is based on exposure two coherent light sources in light field and subsequent development. Distance between light sources and distance from straight line which connects light sources to surface of photographic plate is chosen in such a way to get spatial thickness of interference bands at the surface of plate not to exceed preset thickness of lines per 1 mm. Light sources are subject to exposure at equal exposition in two steps. Diffraction images are built at finite distance from diffraction grating in such a manner that images locate in knots of grating formed by rectangular cells.

EFFECT: improved precision.

5 cl, 2 dwg