US 6,904,241 B2 · Power balanced optical add multiplexer and power balancing methods therefore

Abstract

To improve a power balance of an optical add multiplexer, an add amplifier is optically coupled to an add path of an optical add module. A through loss associated with a signal passing through the add module, and an add loss associated with a signal travelling an add path of the add module are known or otherwise calibrated values. An input power measurement of the signal input to the add module is used in conjunction with the through loss, add loss, and number of added channels to determine an add path amplification value. The gain of the add amplifier is controlled according to add path amplification value so that the power level of added channel(s) substantially matches the power level of the WDM signal output from the add multiplexer. Furthermore, the gain profile of the add amplifier preferably matches a gain profile of a signal input to the add module. In this way, the power level and gain profile of the added channel(s) can be controlled to match the power level and gain profile of the signal passing through the add module. These same techniques may also be applied to an optical add/drop multiplexer that not dropping any channels but is adding at least one channel.

Claims19

Dependent claims

An optical communications apparatus for power balancing a wavelength division multiplexed (WDM) signal output from an add module adding at least one channel to a signal input thereto, comprising:

a gain element optically coupled to the add module and to an add channel port receiving the added at least one channel;
said gain element imparting optical gain to the added at least one channel;
a controller operatively coupled to said gain element, said controller receiving an input power measurement of the signal input to the add module;
and
an optical amplifier supplying said signal input to said add module, said controller determining an add path amplification value based on the input power measurement, a through loss associated with a signal passing through the add module, and an add loss associated with a signal traveling an add path of the add module, said controller controlling said gain element according to the add path amplification value, wherein said gain element and said optical amplifier have substantially matching gain profiles such that a portion of a gain profile of said optical amplifier corresponding to a spectrum associated with said added at least one channel substantially matches a portion of a gain profile of said gain element corresponding to said spectrum.

2 more elements

A method of power balancing a wavelength division multiplexed (WDM) signal output from an add module adding at least one channel to a signal input thereto, comprising:

inputting the signal to the add module via an optical amplifier;
receiving an input power measurement of the signal input to the add module;
determining an add path amplification value based on the input power measurement, a through loss associated with the signal input to the add module and passing though an optical amplifier, and an add loss associated with said added at least one channel traveling an add path of the add module;
and
controlling an add path amplification of the add path according to the add path amplification value, wherein a gain element and said optical amplifier have substantially matching gain profiles such that a spectral portion of a gain profile of said optical amplifier corresponding to a spectrum associated with said added at least one channel substantially matches a portion of a gain profile of said gain element corresponding to said spectrum.

2 more elements

Dependencies are inferred from the claim text.

Power balanced optical add multiplexer and power balancing methods therefore

Life of this patent

Power balanced optical add multiplexer and power balancing methods therefore

Life of this patent

Abstract

Claims19