A beam combining device comprising at least one beam splitter and phase adjustment circuitry. The at least one beam splitter comprises a semi-reflective surface, first and second inputs, and first and second outputs operatively connected to receive first and second light beams. The semi-reflective surface has first and second sides positioned such that light entering from one input is partially reflected through one output and partially transmitted through another output. The phase adjustment circuitry adjusts the relative phases of the first and second light beams so that light transmitted through the semi reflective surface from one input may be adjusted to have a phase which can cancels or constructively adds to light reflected from another input. Light having a combined power of the light beams, or a fraction thereof, may be selectively emitted through a selective output depending upon the adjustment of phases. Also, a method of operation is claimed.