Prospects for diffraction-limited high-power multi-mode fiber amplifiers and amplifier arrays using SBS phase conjugation

Here I discuss the possibilities for scaling to high power by using a multi-mode Yb-core fiber amplifier. The master oscillator must produce light with a narrow frequency bandwith. Such light could be generated using a low-power Nd:YAG laser. I refer to this as pump light, not to be confused with the diode light which pumps the fiber amplifier. Both the pump light and the counter-propagating Stokes light are amplified by the gain medium. I discuss under what conditions it may be possible to control the phase of the Stokes output of such an amplifier by injection seeding the opposite end of the fiber at the Stokes frequency