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US 2012/0069327 A1Published application
Method for measuring optical characteristics of diffraction optical element and apparatus for measuring optical characteristics of diffraction optical element
AssigneePanasonic Corporation
InventorsTakamasa ANDO, Tsuguhiro Korenaga
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Abstract
A measurement method and an evaluating apparatus are provided which are capable of easily and accurately evaluating the light amount of a spot beam, the diffraction efficiency, and the intensity distribution in the optical axis direction by detecting even a weak diffracted beam in an arbitrary wavelength range converged by a diffraction optical element as an imaging lens.
Claims4
1-8. (canceled)
A method for measuring optical characteristics of a diffraction optical element, comprising:
- a filtering step of filtering light emitted from a white light source to obtain a beam in a specified wavelength range;
- a light entering step of allowing the beam in the specified wavelength range to enter an imaging lens composed of the diffraction optical element;
- a magnifying step of magnifying a spot beam as a result of convergence of the beam by the imaging lens;
- a projecting step of projecting the magnified spot beam on a photodetector having a plurality of pixels;
- a distance changing step of changing a distance between the photodetector and the imaging lens in a direction of an optical axis of the spot beam;
- a measuring step of measuring axial-direction intensity distribution in the optical axis direction by the photodetector;
- and
- an identifying step of identifying at least one of (a) each peak point of each-order spot beams and (b) relative scale of light amounts of each-order spot beams, based on the measured axial-direction intensity distribution.
5 more elements
Dependencies are inferred from the claim text.