Optical packet header identifier, optical router incorporating the same therein, and optical routing method using the router

An optical router having function of Optical Add/Drop Multiplexer (OADM) for switching between paths for a specific optical packet out of a plurality of optical packets coupled together and constituting an optical packet train as an optical signal and inserting an optical packet different from said specific optical packet into a location of said specific optical packet, said location becoming empty by switching between paths, said optical router comprising:

• an optical branch for branching said optical packet train input from a first optical transmission input line;
• an optical packet header identifier for receiving one of optical outputs from said optical branch;
• said optical packet header comprising:
• an optical waveguide, a tilted grating for diffracting an optical beam propagating within a core of said optical waveguide toward an outside of said optical waveguide, a set of tilted gratings constituted by said tilted grating and having a thickness of gratings approximately equal to a length occupied in a direction along an optical axis within said optical waveguide by one bit of a signal of an optical packet, and said plurality of sets of tilted gratings are encoded and arranged in a direction along an optical axis based on a specific header code for said optical packet;
• optical beam focusing means for spatially focusing optical beams diffracted by all of the sets of tilted gratings;
• a first photo receiver for receiving said focused optical beams;
• and
• a second photo receiver for receiving an optical beam propagating though said optical waveguide at an output end of said optical waveguide
• an optical delay device for making the other of optical outputs from said optical branch delay by a predetermined time delay;
• and
• an optical switch for outputting at least one optical packet having a header identified by said optical packet header identifier, said optical packet being separated from said optical packet train output from said optical delay device, to a first optical transmission output line, and outputting optical packets excluding said at least one optical packet identified by said optical packet header identifier to a second optical transmission output line, and inserting an optical packet from a second optical transmission input line into a location of said at least one optical packet identified by said optical packet header identifier, based on an output from said optical packet header identifier.