Patent ID: 9634788
Date: 2017-04-25
CPC Classifications: H04B,H04J

Claim:
1. An apparatus, comprising: first and second segments of optical fiber, the first segment of optical fiber being in optical communication with the second segment of optical fiber; a first pump laser configured to supply first pump light having a first pump wavelength to a first segment of optical fiber, the first pump light imparting a first Raman gain at a first wavelength spectrally spaced from the first pump wavelength by a first Stokes shift, such that the first Raman gain imparts a second Raman gain at a second wavelength spectrally spaced from the first wavelength by a second Stokes shift, the second wavelength being a signal wavelength; a second pump laser configured to supply second pump light having a second pump wavelength to the first segment of optical fiber, the second pump light imparting a third Raman gain at the first pump wavelength and the second pump wavelength being spectrally spaced from the first pump wavelength by a third Stokes shift; a third pump laser configured to supply third pump light having the first pump wavelength to the second segment of optical fiber, the third pump light imparting a fourth Raman gain at the first wavelength, such that the fourth Raman gain imparts a fifth Raman gain at the signal wavelength; a fourth pump laser configured to supply fourth pump light having the second pump wavelength to the second segment of optical fiber, the fourth pump light imparting a sixth Raman gain at the first pump wavelength; a first node that receives a first client signal at a time t a second node configured to supply a second client signal at time t wherein the first and second pump lasers are spaced from one another along the first segment of optical fiber, such that only the first pump light is supplied at a first location along the first segment of optical fiber and only the second pump light is supplied at a second location, different than the first location, along the first segment of optical fiber, and the third and fourth pump lasers are spaced from one another along the second segment of optical fiber, such that only the third pump light is supplied at a first location along the second segment of optical fiber and only the fourth pump light is supplied at a second location along the second segment of optical fiber different than the first location along the second segment of optical fiber, each of the first and second pump lights counter-propagates in the first segment of optical fiber relative to an optical signal having the signal wavelength, each of the third and fourth lights counter-propagates in the second segment of optical fiber relative to the optical signal.