Optical amplifier and a method of light amplification
OwnerLijie QIAOinventor
Life of this patent
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Abstract
An optical amplifier has a pump and an “anti-pump” for reducing a variation of the amplifier gain with the input optical power. The wavelength of “anti-pump” light is longer than the wavelength of the optical signal being amplified, so that the optical signal serves as a pump for the “anti-pump” light, whereby an optical loss variation with the signal power at the signal wavelength is created, which reduces optical gain variation with the signal power. To compensate for gain loss due to the anti-pump light, two and three stages of amplification can be used.
Claims20
An optical amplifier for amplifying an optical signal having a signal wavelength and a signal power, the optical amplifier having an amplifier gain, the optical amplifier comprising:
- an optical medium doped with a rare earth element;
- an optical pump for pumping the optical medium with a pump light, whereby an optical gain at the signal wavelength is created in the optical medium, wherein the optical gain is dependent on the signal power;
- and
- an optical anti-pump for pumping the optical medium with an anti-pump light at an anti-pump wavelength longer than the signal wavelength, so as to create a dependence of an optical loss in the optical medium on the signal power, substantially compensating the dependence of the optical gain on the signal power and thereby lessening a variation of the amplifier gain with the signal power.
A method for lessening a gain compression in an optical amplifier for amplifying an optical signal having a signal wavelength and a signal power, the optical amplifier having a rare earth element doped optical medium and an optical pump for pumping the optical medium at a pump wavelength, for inducing an optical gain in the optical medium, wherein the optical gain exhibits a first variation with the signal power, the method comprising:
- pumping the optical medium at an anti-pump wavelength longer than the wavelength of the optical signal, for inducing a second variation of optical gain with the signal power, which is substantially complementary to the first variation, whereby the gain compression in the waveguide amplifier is lessened,
- wherein a pumping power level at the anti-pump wavelength is substantially independent of a transient change of the signal power.
Dependencies are inferred from the claim text.