A means and method for dual-phase amplification of wave-type signals is disclosed comprising superimposing a constant level beam set (A) and a modulated beam set (B) to produce a first interference image (22) at first (23) and second (24) locations. A first image component separator (25) separates energy from constructive and destructive interference component regions to produce secondary beam sets that are combined to produce a second interference image (28) which is separated at a destructive interference region to produce the output. The amplifier with multiple inputs is then connected in cascade, as a phase-bistable device, as a level detector, an AND, an OR, and/or a synchronized oscillator. Multiple frequencies work independently, allowing for frequency-multiplexed functions.