Abstract: A coherent input beam from a laser is fed into a Brillouin-enhanced four wave mixer which generates a phase conjugated seed beam in counterpropagation with the input beam. A brillouin amplifier is provided between the laser and four wave mixer to transfer energy from the input beam to the seed beam and thereby amplify the seed beam to produce a phase conjugated output beam with approximately 50% of the energy of the input beam and narrow bandwidth which is free from random phase jumps associated with the acoustic noise generally required to initiate and sustain stimulated Brillouin scattering. The phase conjugated output beam can be modulated or steered in direction, as desired. Reference beams for the four wave mixer may be derived from the same laser source as the input beam and have energies one or more orders of magnitude smaller than the energy of the input beam.