Combined shearing interferometer and Hartmann wavefront sensor
US4518854A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 17, 1982 |
| Grant date | May 21, 1985 |
| Priority date | — |
| Expiry date | Jun 17, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/0215
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensitive wavefront sensor combining attributes of both a Hartmann type of wavefront sensor and an AC shearing interferometer type of wavefront sensor. An incident wavefront, the slope of which is to be detected, is focussed to first and second focal points at which first and second diffraction gratings are positioned to shear and modulate the wavefront, which then diverges therefrom. The diffraction patterns of the first and second gratings are positioned substantially orthogonal to each other to shear the wavefront in two directions to produce two dimensional wavefront slope data for the AC shearing interferometer portion of the wavefront sensor. First and second dividing optical systems are positioned in the two diverging wavefronts to divide the sheared wavefront into an array of subapertures and also to focus the wavefront in each subaperture to a focal point. A quadrant detector is provided for each subaperture to detect the position of the focal point therein, which provides a first indication, in the manner of a Hartmann wavefront sensor, of the local wavefront slope in each subaperture. The total radiation in each subaperture, as modulated by the diffraction grating, is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.