Tyco Telecommunications (us) Inc.

Michael A Mills

Morten Nissov

Chinlon Lin

Alexei N Pilipetskii

Bo Pedersen

George T Harvey

Gregory M Wolter

Yanjie Chai

A hybrid Raman-EDFA provides gain equalization over the C-band and L-band. The hybrid Raman-EDFA includes a Raman section producing a Raman gain and an EDFA section producing an EDFA gain complementing the Raman gain. The EDFA section preferably includes a highly inverted, single-stage EDFA to produce the complementing EDFA gain shape. One embodiment of the EDFA section includes a high return loss termination located after the erbium fiber to receive unabsorbed pump power. Multiple hybrid Raman-EDFAs can be connected in an amplifier chain in a transmission system. The transmission system preferably provides a dispersion map including regular composite fiber spans followed by at least one compensating span of negative dispersion fibers. The Raman sections of the hybrid Raman-EDFAs are preferably coupled to negative dispersion fiber in the transmission system.

Hybrid Raman/erbium-doped fiber amplifier and transmission system with dispersion map

An apparatus for measuring the noise figure in optical amplifiers employed for large bandwidth applications such as dense wavelength division multiplexing systems. A booster amplifier coupled to a light source increases the average power associated with a plurality of optical channels. A periodic filter is coupled to the booster amplifier to reflect noise between each of the optical channels across the predetermined bandwidth. An amplifier under test is coupled to the periodic filter and the noise figure associated with the amplifier under test is measured.

Method and apparatus for measuring noise figure in optical amplifiers

A test apparatus includes a broadband noise source, a test station, and a spectrum analyzer. A method using the test apparatus to measure the spectral gain of an erbium doped fiber amplifier (EDFA) under test includes steps of providing an optical signal from a broadband noise source to an input of the EDFA under test, measuring a power at a test wavelength at an output of the EDFA under test, adjusting the test wavelength, and repeating the steps of measuring and adjusting for a predetermined number of times.

Method and apparatus to measure gain spectra of erbium doped fiber amplifier

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Freehold, NJ, United States of America

Michael A Mills