Optical waveguide device and optical hybrid circuit

An optical hybrid circuit comprising:

• an optical waveguide device including:
• a first optical coupler branching an input light to output a first signal light and a second signal light;
• an optical phase shifter for giving a phase difference between the first signal light and the second signal light including:
• a first optical waveguide connected to the first optical coupler and propagating the first signal light;
• and
• a second optical waveguide having an optical path length different from that of an optical path length of the first optical waveguide, connected to the first optical coupler and propagating the second signal light;
• and
• a second optical coupler for coupling the first signal light outputted from the first optical waveguide and the second signal light outputted from the second optical waveguide connected to the first optical waveguide and the second optical waveguide of the optical phase shifter, wherein
• the first optical waveguide has a first waveguide width and is a bent optical waveguide bent in a first direction at a first radius of curvature,
• the second optical waveguide has a second waveguide width and is a bent optical waveguide bent in a second direction at a second radius of curvature,
• the first waveguide width and the second waveguide width are equal to each other,
• the first direction and the second direction are the same,
• the first radius of curvature and the second radius of curvature are the same,
• the first optical coupler has two input ports and four output ports forming two pairs of output channels, and
• the first optical waveguide and the second optical waveguide are connected to one of the two pairs of output channels;
• a photoelectric converting unit converting to electric signals an optical signal outputted from the other pair of output ports of the first optical coupler and an optical signal outputted from the output port of the second optical coupler;
• and
• a computing unit executing a processing of discriminating the input light, based on the electric signals, wherein
• a bend angle of the first optical waveguide and a bend angle of the second optical waveguide are different from each other.

An optical hybrid circuit comprising:

• an optical waveguide device including:
• a first optical coupler branching an input light to output a first signal light and a second signal light;
• an optical phase shifter for giving a phase difference between the first signal light and the second signal light including:
• a first optical waveguide connected to the first optical coupler and propagating the first signal light;
• and
• a second optical waveguide having an optical path length different from that of an optical path length of the first optical waveguide, connected to the first optical coupler and propagating the second signal light;
• and
• a second optical coupler for coupling the first signal light outputted from the first optical waveguide and the second signal light outputted from the second optical waveguide connected to the first optical waveguide and the second optical waveguide of the optical phase shifter, wherein
• the first optical waveguide has a first waveguide width and is a bent optical waveguide bent in a first direction at a first radius of curvature,
• the second optical waveguide has a second waveguide width and is a bent optical waveguide bent in a second direction at a second radius of curvature,
• the first waveguide width and the second waveguide width are equal to each other,
• the first direction and the second direction are the same,
• the first radius of curvature and the second radius of curvature are the same, and
• the second optical coupler is an optical coupler having two input ports and two output ports;
• a photoelectric converting unit converting to electric signals an optical signal outputted from the other pair of output ports of the first optical coupler and an optical signal outputted from the output port of the second optical coupler;
• and
• a computing unit executing a processing of discriminating the input light, based on the electric signals, wherein
• a bend angle of the first optical waveguide and a bend angle of the second optical waveguide are different from each other.