Patent attributes
Embodiments of the present disclosure are directed toward techniques and configurations for optical couplers comprising a first optical waveguide and a second optical waveguide coupled to form a 2×2 optical unitary matrix to receive a respective first input optical signal and a second input optical signal. In embodiments the first optical waveguide and second optical waveguide form arms that converge alongside each other to direct the first input optical signal and the second input optical signal along a path that integrates a plurality of tunable phase shifters to transform the first input optical signal or the second input optical signal into a first output optical signal and second output optical signal to be output from the 2×2 optical unitary matrix. Additional embodiments may be described and claimed.