Apparatus and method for a symmetric sequential entangler of periodic photons in a single input and output mode

An apparatus for sequentially entangling photons, comprising:

• a waveguide chip having integrated optical components and interconnecting optical
• waveguide disposed therein, wherein said optical components further comprise an input port connected to said optical waveguide for inputting said photons into said waveguide chip;
• a polarization controller connected to said input port for rotating the polarization of said input port;
• a plurality of loop back paths having matched delay lines disposed in each for synchronizing said photons in time;
• a plurality of multimode interferometers for selectably routing said photons through any of said interconnecting optical waveguide;
• a controller for switching the input mode of any of said plurality of multimode interferometers so as to route said photons out of a selected interferometer output port;
• a clock source for synchronizing said controller with the arrival of said photons;
• an entangling gate having bypass and entangling inputs and bypass and entangling outputs for selectively entangling said photons;
• and
• an output port for routing said entangled photons out of said waveguide chip.