The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 08, 2014
Filed:
Jun. 30, 2011
Juan C. Juarez, Windsor Mill, MD (US);
David W. Young, Clarksville, MD (US);
Joseph E. Sluz, Ellicott City, MD (US);
Juan C. Juarez, Windsor Mill, MD (US);
David W. Young, Clarksville, MD (US);
Joseph E. Sluz, Ellicott City, MD (US);
The Johns Hopkins University, Baltimore, MD (US);
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.