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:
Jun. 18, 2002
Filed:
Mar. 06, 2000
Frank Shum, Sunnyvale, CA (US);
Ditech Corporation, Mountain View, CA (US);
Abstract
An apparatus and method are provided for amplifying a signal having several multiplexed channels of different wavelengths. In one embodiment, an amplifier is provided having a doped fiber coupled to an input , a pump coupled to the doped fiber to provide an output to amplify the signal therein and a control system for controlling the pump. The control system has a detector for measuring power of the signal and a controller for adjusting power to the pump based on predetermined criteria and the measured signal power. The pump power is adjusted as a linear function of the signal power by including within the predetermined criteria a multiplier by which the signal power is multiplied, and an offset that is added to the product of the multiplier and the signal power to ensure that the power applied to the pump is non-zero even for zero signal power. Preferably, the controller can automatically adjust pump power to provide equal and constant gain to each channel even when channels are added or removed. More preferably, the controller can provide a transient response of less than 200&mgr;s when channels are added or removed.