Apparatus for redirecting radiation
US7176827B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2003 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Jul 7, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/89
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for redirecting radiation including a polarization dependent reflector and an optical component able to transform the polarisation of radiation as it passes through the component. Radiation having a first polarisation component impinging upon the reflector from a source is reflected towards a scene area. Radiation not having this polarisation component passes through the reflector. The radiation having the first polarisation is then transmitted towards a scene via the optical component. As the radiation passes via the optical component, reflects back from the scene and passes again via the optical component, the polarisation is changed to state where it can now pass through the polarisation dependent reflector. The apparatus allows a scene to be illuminated as if the illuminator were positioned at the viewpoint of an imaging system, and so aids uniform illumination of the scene. The apparatus is particularly suited to mm-wave systems, wherein the reflector may comprise a parallel wire grid polarizer, and the optical component may comprise a quarter-wave plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.