Harmonically matched diffraction grating pair
US7609392B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2007 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Aug 18, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/45
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and device realize shallow gratings-based planar beam splitter/combiner. Non-trivial phase shifts between different ports of resulting interferometers are used to acquire full-field phase measurements. The non-trivial phase shifts between different ports of the planar beam splitter/combiner can be adjusted by simply shearing one grating with respect to the second grating. The two shallow diffraction gratings are harmonically-related and can be recorded on a single substrate for compact interferometric based schemes. During the recording process, the two gratings are aligned such that the grating planes and the grating vectors are parallel to that of each other. The relative phase of the recording beams controls the shearing between the recorded harmonically-related shallow phase gratings. The relative shearing of the two gratings defines the non-trivial phase shift between different ports of the compact planar beam splitter/combiner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.