An integrated photonics arrayed waveguide multiplexing/demultiplexing device is disclosed. The device includes an array of waveguides having an incident light waveguide section including a phase correcting region, a transmitted light waveguide section, a tunable reflector, wherein each pair of consecutive waveguides in the array includes a coupler. The coupler configured to combine light from the transmitted light waveguide sections, determine therefrom an optical phase difference between the two consecutive waveguides, and wherein the couplers are further configured to determine therefrom a change in optical path length required for each of two consecutive waveguides to reach a predetermined optical phase difference, and wherein each phase correcting region is configured to apply the change to correct the optical path length of the respective waveguide.