Method of measuring refractive indices of lens and sample liquid
US5151752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1991 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | May 28, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/0342
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of measuring a refractive index distribution of a lens is disclosed which comprises, immersing a glass sample and a lens under test within a matching fluid whose refractive index differs slightly from that of the glass to be tested, the glass sample having a refractive index and a shape which are both known and the lens to be tested having an unknown refractive index but a known shape, allowing coherent light to pass through the glass sample and the lens under test; superposing the transmitted light wave on a reference light wave to generate interference fringes, outputting the intensity distribution of interference fringes that are generated by the light wave that has passed through the glass sample, determining the refractive index of the matching fluid on the basis of the resulting output, outputting the intensity distribution of interference fringes that are generated by the light wave that has passed through the lens under test; separating from the resulting output the defocus term and aberration terms in the polynomial which expresses the produced interference fringes; determining the average refractive index of the lens under test from the separated defocus term and…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.