Patent ID: 6631025
Filing Date: 2003-10-07
Classification: H01S,H04B

Abstract:
A multi-stage Raman amplifier apparatus, comprising:a first Raman amplifier configured to receive a signal of at least one wavelength traveling in an upstream direction in the first Raman amplifier; a first pump source coupled to the first Raman amplifier producing a first pump beam in a downstream direction that is counter-propagating relative to the signal; a second pump source coupled to the first Raman amplifier producing a second pump beam that travels in the upstream direction; a second Raman amplifier coupled to the first Raman amplifier, wherein one of the first Raman amplifier and the second Raman amplifier comprises a distributed Raman amplifier and the other of the first Raman amplifier and the second Raman amplifier comprises a discrete Raman amplifier; and a third pump source coupled to the second Raman amplifier producing a third pump beam traveling in the downstream direction.