Fiber-optic automatic gain control systems and methods
US8774635B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2011 |
| Grant date | Jul 8, 2014 |
| Priority date | — |
| Expiry date | Nov 21, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/1121
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Methods and systems to control a gain applied to a free-space optical (FSO) signal to reduce time-varying intensity fluctuations. An optical pre-amplifier may provide a first, relatively moderate gain with low noise factor (NF). A second optical amplifier may provide a second gain. Amplification may include doped fiber amplification (DFA), such as erbium-doped fiber amplification (EDFA) and/or Raman amplification. A variable optical attenuator (VOA) may be controllable with a relatively fast response time to reduce the time-varying intensity fluctuations. The VOA may effectively control an overall system gain. The gain of the first and/or second optical amplifier may also be controllable to reduce the time-varying intensity fluctuations. Optical intensities may be detected at one or more locations to support one or more feed-forward and/or feedback control loops. A clamp may be applied when an optical power reaches a threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.