Patent ID: 7079310

Claim:
An optical amplifier for amplifying optical signals, said optical amplifier having an input facet and an output facet, said optical amplifier comprising: a gain medium defining an amplifier axis; and a plurality of gain clampers disposed along the amplifier axis to control the local carrier density distribution of the gain medium of the optical amplifier, each of said gain clampers being constructed by grating structures arranged in an in-axis form along the amplifier axis, and the gain clamping efficiencies of the grating structures declining from the input facet to the output facet, wherein the more the grating structures approach the output facet, the larger the magnitude of structure discontinuity of the grating structures is, and wherein the whole carrier density distribution of the optical amplifier is controlled by the gain clampers, the whole carrier density distribution of the optical amplifier declines from the input facet to the output facet, and the resulting local saturation photon density is larger than the local photon density of the amplified optical signal.