Patent ID: 8773752

Claim:
Optical Raman fiber amplifier wherein pump light in an optical fiber amplifies a light signal which corresponds to a Stokes Line of a Raman process, comprising a pump laser having a power of more than 10 Watt generating the pump light; an amplification fiber having a total length of less than 300 m, wherein at least one section thereof has a ratio of Raman gain coefficient g R to Brillouin g B gain coefficient of g R /g B larger than 0.001 at the fiber operating temperature and a vacuum wavelength of 1064 nm; and wherein the Raman gain coefficient is mathematically described as ⅆ I s ⅆ z = g R ⁢ I s ⁢ I p - α s ⁢ I s , where z is distance along the fiber, I S denotes the signal intensity, I p the pump intensity, g R the Raman gain coefficient, and α s denotes linear light attenuation, and the Brillouin gain coefficient is mathematically described as ⅆ I s ⅆ z = - g B ⁢ I s ⁢ I p - α s ⁢ I s , where g B is the Brillouin gain coefficient and the first minus sign indicates power loss.