Optical fiber mode separation systems
US4381137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1981 |
| Grant date | Apr 26, 1983 |
| Priority date | — |
| Expiry date | Mar 5, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
When a multimode optical fiber is deformed in accordance with an input signal to be sensed, light from lower order core modes is coupled to higher order core modes. A lens assembly is provided which separates the light in the higher order core modes from the light remaining in the lower order core modes. A spatial filter in the lens assembly enables the lens or lenses therein to couple the separated modes to two different output fibers with high efficiency and low coupling loss. The two signals in the output fibers are processed so that the common components which constitute noise are cancelled, while the signal components are additively combined and appear at the system's output so as to provide a highly sensitive, low noise fiber optic sensor system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.