Light intensity attenuator for optical transmission systems
US5642456A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1993 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Sep 14, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S385/902
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a variable attenuator for an optical transmission system having a disc-like masking plate with apertures (or image zones) formed in an arcuate control area at the periphery of the plate. Within each aperture, at least one opaque masking member is provided extending outward from the origin to the perimeter of the aperture and having a masking surface with an incremental masking area which continuously increases in magnitude with increasing radial length of the aperture. The perpendicular cross-section of each masking member with respect to the optical axis preferably forms a geometric shape having straight-line edges extending radially outward from the origin of the aperture. In the preferred embodiment, a plurality of masking members are utilized (as a pair or sets of pairs). The disc-like masking plate is inserted perpendicularly into the path of the light beam such that the optical axis of the light beam defines a movement axis about the periphery of the masking plate upon which the origin of each aperture is placed. In this manner, rotation of the masking plate around its center provides discrete levels of attenuation of the light beam as successiv…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.