These devices utilize the principle of stimulated Raman scattering to amplify optical signals. Typically, the Raman gain medium comprises optical fibers, bulk crystals, waveguides in photonic integrated circuits, or cells filled with gas or liquid. Raman amplification / ˈrɑːmən / is a way of increasing the signal strength in an optical fiber. The basic principles for SRS are as follows: If weak signal light and strong pump light are transmitted along a. Raman amplifier is a well-known amplifier configuration. This amplifier uses conventional fiber (rather doped fibers), which may be co-or counter-pumped to provide amplification over a wavelength range which is a function of the pump wavelength.