Raman amplification
Raman amplification /ˈrɑːmən/ is a way of increasing the signal strength in an optical fiber. It is often used in a fiber that carries a signal for a long distance (such as in an undersea cable). Technically, it works by stimulating Raman scattering, in which a lower frequency ''signal'' photon induces inelastic scattering of a higher-frequency ''pump'' photon in an optical medium in the nonlinear regime. As a result, another ''signal'' photon is produced, with the surplus energy resonantly passed to the vibrational states of the
