Second-Order Fiber Raman Amplifier

The second-order fiber Raman amplifier builds upon the first-order amplifier by incorporating pump lasers in the 1340–1360 nm band. These pumps provide Raman gain to the first-order Raman laser at 14xx nm, effectively reducing system noise. It is ideally suited for optical signal amplification in ultra-long-haul unrepeatered transmission systems. This second-order amplifier must be used together with a first-order fiber Raman amplifier.