Optical modulator and transmitter
AssigneeFujitsu Limited
InventorMasaki Sugiyama
Life of this patent
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Abstract
To reduce wavelength chirp and produce multi-valued signal light that can be readily demodulated on a receiver side, a Mach-Zehnder type optical modulator includes an incident waveguide that branches input light, a pair of optical waveguides that respectively transmit the branched light and exhibit an electro-optic effect, a pair of signal electrodes arranged along the optical waveguides, and an exit waveguide that outputs an interfered light of the light transmitted through the optical waveguides. Furthermore, at a boundary, the polarity of each of the optical waveguides reverses, and either the optical waveguides or the signal electrodes cross each other.
Claims27
A Mach-Zehnder type optical modulator comprising:
- an incident waveguide that branches input light into branched lights;
- a pair of optical waveguides including a first optical waveguide and a second optical waveguide that respectively transmit the branched lights and exhibit an electro-optic effect;
- a pair of signal electrodes including a first signal electrode and a second signal electrode respectively arranged along the pair of optical waveguides;
- and
- an exit waveguide that outputs an interfered light of the branched lights transmitted respectively through the pair of optical waveguides, wherein
- polarizations of the pair of optical waveguides are reversed respectively at a boundary, and
- any one of a crossing of the first optical waveguide and the second optical waveguide or a crossing of the first signal electrode and the second electrode occurs near the boundary.
A Mach-Zehnder type optical modulator comprising:
- an incident optical waveguide that receives a light and branches the light;
- a pair of optical waveguides that are formed on a substrate exhibiting an electro-optic effect and respectively transmit the light branched by the incident optical waveguide;
- a pair of signal electrodes that respectively correspond to the pair of optical waveguides individually and are arranged accordingly along the pair of optical waveguides;
- and
- an exit optical waveguide that outputs an interfered light of the branched lights transmitted respectively through the pair of optical waveguides and transmits the interfered light as a signal light, wherein
- a polarization reversing region where polarization is reversed and a polarization non-reversing region where polarization is not reversed are formed on the substrate bordered by a boundary on the substrate,
- correspondences between the pair of signal electrodes and the pair of optical waveguides, switch near the boundary, and
- a first optical waveguide and a second optical waveguide of the pair of optical waveguides cross each other near the boundary, and the correspondences switch.
The Mach-Zehnder type optical modulator comprising:
- an incident optical waveguide that receives a light and branches the light;
- a pair of optical waveguides that are formed on a substrate exhibiting an electro-optic effect and respectively transmit the light branched by the incident optical waveguide;
- a pair of signal electrodes that respectively correspond to the pair of optical waveguides individually and are arranged accordingly along the pair of optical waveguides;
- and
- an exit optical waveguide that outputs an interfered light of the branched lights transmitted respectively through the pair of optical waveguides and transmits the interfered light as a signal light, wherein
- a polarization reversing region where polarization is reversed and a polarization non-reversing region where polarization is not reversed are formed on the substrate bordered by a boundary on the substrate,
- correspondences between the pair of signal electrodes and the pair of optical waveguides, switch near the boundary, and
- a first signal electrode and a second signal electrode of the pair of signal electrodes crosses each other three-dimensionally near the boundary, thereby causing the correspondences between the pair of signal electrodes and the pair of optical waveguides to switch.
Dependencies are inferred from the claim text.