Patent ID: 11888281
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Optics (Instruments)
Classification: CPC H | IPC H

Claim 0:
1. A multimode optical amplifier that provides gain to a plurality of propagation modes of signal light, the multimode optical amplifier comprising:
a multiplexer that multiplexes the signal light and excitation light;
an amplifying fiber which has a core that propagates a predetermined plurality of propagation modes of the signal light and a predetermined plurality of propagation modes of the excitation light, and which provides an individual gain value for each of the predetermined propagation modes of the signal light;
a wavelength-flattening filter that maintains a constant gain value for a frequency for all predetermined propagation modes of the signal light; and
a mode-flattening filter that maintains the gain value at a constant value for a predetermined propagation mode of the signal light for all predetermined propagation modes of the signal light.