Raman amplifier with gain control
AssigneeAlcatel
InventorsDominique Annie Mongardien, Dominique Bayart
Life of this patent
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Abstract
A two-stage Raman amplifier provides a gain control compensating for span loss variations and changing channel loading. A first amplifier stage (S1) has a first amplifying medium (F1) and a first pump light source (P1, P2, Pn), which is controlled and adjusted by a control unit (CU) to compensate for span loss variations. A second amplifier stage (S2) has a second amplifying medium (F2) and a second pump light source (P′1, P′2, P′n), which is controlled and adjusted by the control unit (CU) to balance changing channel loading.
Claims11
An optical amplifier comprising
- a first amplifier stage comprising a first gain medium and a first pump light source coupled to said first gain medium to launch a pump light signal therein for amplifying an optical signal traversing said first medium by stimulated Raman scattering;
- a second amplifier stage comprising a second gain medium and a second pump light source coupled to said second gain medium to launch a pump light signal therein for amplifying the optical signal traversing said second medium by stimulated Raman scattering;
- and
- a control unit for monitoring the optical signal and for adjusting a pump power of the first pump light source to varying input signal attenuation and for adjusting a pump power of the second pump light source to a changing number of wavelength channels in the optical signal.
A method of controlling the gain of a Raman amplifier, said method comprising the steps of
- launching a pump light signal into a first gain medium of a first amplifier stage of said Raman amplifier for amplifying an optical signal traversing said first medium by stimulated Raman scattering;
- launching a pump light signal into a second gain medium of a second amplifier stage of said Raman amplifier for amplifying the optical signal traversing said second medium by stimulated Raman scattering;
- monitoring the optical signal;
- adjusting a pump power of the first pump light source to varying input signal attenuation;
- and
- adjusting a pump power of the second pump light source to a changing number of wavelength channels in the optical signal.
Dependencies are inferred from the claim text.