Patent ID: 7477446
Filing Date: 2009-01-13
Classification: H01S,H04B

Abstract:
1. An amplification system employing Raman amplification with a plurality of first-order Raman pumps and at least one second-order Raman pump which amplifies the first-order Raman pumps, the first- and second-order Raman pumps counter-propagating to signal light in an optical fiber, the amplification system comprising: a plurality of light sources generating pump light of the first- and second-order pumps; and a modulator unit modulating the pump light of the first- and second-order pumps such that pump power of modulated pulses of the at least one second-order pump does not overlap with pump power of modulated pulses of the first-order pumps at a launching point of the pump light in the optical fiber, and such that pump power of modulated pulses of the at least one second-order pump overlaps with pump power of modulated pulses of the first-order pumps at a position distant from the launching point, by using a first timing for the pump light of the first-order pumps and a second timing relatively different from the first timing for the pump light of the at least one second-order pump to allow flattening lateral signal power distribution along the optical fiber.