Diffractive optical element having periodically repeating phase mask and system for reducing perceived speckle
US8152307B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2009 |
| Grant date | Apr 10, 2012 |
| Priority date | — |
| Expiry date | Dec 31, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/2053
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A optical apparatus (201) for use in an laser imaging system (200) is provided. The optical apparatus (201) includes one or more optical elements (215) that are configured to create an intermediate image plane (217) in the laser imaging system (200). A diffractive optical element (216) is then disposed at the intermediate image plane (217) to reduce speckle. The diffractive optical element (216) includes a periodically repeating phase mask (218) that can be configured in accordance with steps, vortex functions, Hermite-Gaussian functions, and so forth. Smooth grey-level phase transitional surface (337) can be placed between elements (333,334) to improve brightness and image quality. The periodically repeating phase mask (218) makes manufacture simple by reducing alignment sensitivity, and can be used to make applicable safety standards easier to meet as well.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.