Heterodyne wavefront sensor
US6229616A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1999 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Apr 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical heterodyne wavefront sensor uses a radio frequency (RF) signal for measuring an optical wavefront having a state of phase that differs throughout its aperture. It comprises a lens, optical fiber and optical frequency shifter arrangement to develop a reference optical wavefront having substantially the same phase throughout and that is shifted in frequency by an amount corresponding to the RF. A beam combiner interferometrically combines the optical wavefront and the shifted reference optical wavefront into a heterodyne optical signal at the RF frequency, each subaperture of which has a phase that corresponds to the state of phase of a like subaperture of the optical wavefront. An array of lenses focuses the optical heterodyne signal into an array of photodetectors, each responsive to a subaperture and that produces an electrical signal at the optical beat frequency corresponding to the RF and having a phase corresponding to the state of phase of the corresponding subaperture of the optical wavefront. A plurality of circuit chains, each including a digital divider, responds to the RF signal and a corresponding one of the array of electrical signals and with an exclusive O…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.