Electro-optic modulator, optical chip, and integrated chip

An optical chip comprising:

• a substrate, and
• an electro-optic modulator disposed on a surface of a substrate, the electro-optic modulator comprising:
• an optical waveguide layer disposed on the substrate;
• modulation electrodes disposed on the optical waveguide layer;
• and
• a dual-rail metal electrode disposed on and electrically connected to the modulation electrodes,
• a first end of the dual-rail metal electrode connected to a radio frequency driver, the dual-rail metal electrode being configured and connected to supply power to the radio frequency driver through a direct-current coupling free of inline DC blocking capacitors;
• the dual-rail metal electrode configured to receive a modulation signal input from the radio frequency driver,
• the modulation electrode configured to perform electro-optic modulation on the optical waveguide layer based on the modulation signal input;
• a second end of the dual-rail metal electrode connected to a direct-current voltage terminal, and
• the direct-current voltage terminal being configured to input a voltage and provide a direct-current bias voltage for the radio frequency driver through the dual-rail metal electrode,
• wherein the optical waveguide layer comprises:
• an electro-optic crystal layer parallel to the substrate, and a ridge waveguide disposed on a side of the electro-optic crystal layer that is away from the substrate surface, the modulation electrodes are configured to perform electro-optic modulation on a light wave transmitted by the ridge waveguide,
• the ridge waveguide comprising:
• a first branch and a second branch that are symmetrically disposed,
• an input end of the first branch is coupled to an input end of the second branch, an output end of the first branch is coupled to an output end of the second branch, a first end of the modulation electrodes is coupled to the input ends of the first branch and the second branch, and a second end of the modulation electrodes is coupled to the output ends of the first branch and the second branch;
• and
• the first end of the modulation electrodes is coupled to a signal output end of the radio frequency driver, the second end of the modulation electrode is connected to a terminal resistor, and a phase of an optical signal that is output from the first branch is opposite to a phase of an optical signal that is output from the second branch,
• the modulation electrodes comprise a first electrode pair and a second electrode pair, the first electrode pair is symmetrically disposed on first and second sides of the first branch, and the second electrode pair is symmetrically disposed on first and second sides of the second branch, and
• wherein the dual-rail metal electrode is disposed on the first side and the second side of both the first branch and the second branch and is configured to provide a differential voltage to the first electrode pair and the second electrode pair.

An integrated chip comprising:

• an electrical chip, and
• an optical chip,
• the electrical chip being disposed on a surface of the optical chip,
• the electrical chip being connected to the optical chip through welding by using a solder ball,
• the optical chip comprising a substrate and an electro-optic modulator disposed on a surface of a substrate,
• the electro-optic modulator comprising:
• an optical waveguide layer disposed on the substrate;
• modulation electrodes disposed on the optical waveguide layer;
• and
• a dual-rail metal electrode disposed on the modulation electrode and electrically connected to the modulation electrodes,
• a first end of the dual-rail metal electrode connected to a radio frequency driver;
• the dual-rail metal electrode being configured to receive a modulation signal input from the radio frequency driver,
• the dual-rail metal electrode being connected to provide direct-current coupling to the radio frequency driver free of inline DC blocking capacitors,
• the modulation electrodes being configured to perform electro-optic modulation on the optical waveguide layer based on the modulation signal input;
• a second end of the dual-rail metal electrode being configured to be coupled to a direct-current voltage terminal configured to input a voltage and provide a direct-current bias voltage for the radio frequency driver by using the dual-rail metal electrode;
• wherein the optical waveguide layer comprises:
• an electro-optic crystal layer parallel to the substrate, and a ridge waveguide disposed on a side of the electro-optic crystal layer that is away from the substrate surface, the modulation electrodes are configured to perform electro-optic modulation on a light wave transmitted by the ridge waveguide,
• the ridge waveguide comprising:
• a first branch and a second branch that are symmetrically disposed,
• an input end of the first branch is coupled to an input end of the second branch, an output end of the first branch is coupled to an output end of the second branch, a first end of the modulation electrodes is coupled to the input ends of the first branch and the second branch, and a second end of the modulation electrodes is coupled to the output ends of the first branch and the second branch;
• and
• the first end of the modulation electrodes is coupled to a signal output end of the radio frequency driver, the second end of the modulation electrode is connected to a terminal resistor, and a phase of an optical signal that is output from the first branch is opposite to a phase of an optical signal that is output from the second branch,
• the modulation electrodes comprise a first electrode pair and a second electrode pair, the first electrode pair is symmetrically disposed on first and second sides of the first branch, and the second electrode pair is symmetrically disposed on first and second sides of the second branch, and
• wherein the dual-rail metal electrode is disposed on the first side and the second side of both the first branch and the second branch and is configured to provide a differential voltage to the first electrode pair and the second electrode pair.