Patent · US Expired

Method and apparatus for evaluating aberrations of optical element and method and apparatus for adjusting optical unit and lens

US6809829B1 · kind B1 · utility

55Cited by
1References
49Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 18, 2000
Grant dateOct 26, 2004
Priority date
Expiry dateMay 18, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01M11/0228
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A lens evaluation method includes diffracting light derived from a lens so that two diffracted rays of different orders (e.g., a 0th-order diffracted ray and a +1st-order diffracted ray) interfere with each other, thereby obtaining a shearing interference figure, and changing phases of the diffracted rays. The method also includes in the shearing interference figure, determining phases of light intensity changes at a plurality of measuring points on a measuring line which passes through a midpoint of a line segment interconnecting optical axes of the two diffracted rays, and determining characteristics (defocus amount, coma, astigmatism, spherical aberration and a higher-order aberration) of the lens based on the phases.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.