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. 06, 2004
Filed:
Oct. 11, 2002
Daniel Ratoff, San Jose, CA (US);
Paul Nathan Freeman, Saratoga, CA (US);
JDS Uniphase Corporation, San Jose, CA (US);
Abstract
The present application relates to a doped fiber amplifier having an increased dynamic range, and particularly for laser pump sources and a method of pumping erbium doped fiber amplifiers over a greater dynamic range. In a multi-channel optical system, optical amplifiers must be able to provide gain over a larger range of signal powers, the dynamic range corresponding to the number of channels in the link. The present invention has found that the dynamic range of an EDFA can be significantly increased by using pulse width modulation to pulse pump current at or near the minimum current stability threshold, in order to produce lower power output. The duty cycle of the pulsed current is selected to achieve a time-averaged operating condition taking advantage of the relatively long relaxation time of the erbium. Thus the time averaged pump power can be reduced in a linear fashion well below the capability of a continuous wave system.