Optical phased array chip, control method, and waveguide optical phased array system

An optical phased array chip, comprising at least two optical splitting stages;

• each of the optical splitting stages comprises optical waveguide branches;
• each of the optical waveguide branches in each of the optical splitting stages comprises an optical splitter, a first optical waveguide, a second optical waveguide, a first thermal-optic phase shifter and a second thermal-optic phase shifter, the first thermal-optic phase shifter being integrated on the first optical waveguide, the second thermal-optic phase shifter being integrated on the second optical waveguide, the optical splitter having a first output port connected to a first end of the first optical waveguide and a second output port connected to a first end of the second optical waveguide;
• and a second end of a first thermal phase shifter and a second end of a second thermal phase shifter in each of the optical waveguide branches in a previous optical splitting stage are respectively connected to input ports of the two optical splitters in a next optical splitting stage, the optical waveguide branches in a next optical splitting stage having a number twice that of the optical waveguide branches in a previous optical splitting stage;
• wherein first ends of all the first thermal-optic phase shifters in each of the optical waveguide branches are connected to a preset voltage, first ends of all the second thermal-optic phase shifters are grounded, a second end of the first thermal-optic phase shifter and a second end of the second thermal-optic phase shifter in a same one of the optical waveguide branches are connected to a common controlled voltage, and a resistance of the first thermal-optic phase shifter and a resistance of the second thermal-optic phase shifter in one of the optical waveguide branches are the same;
• and
• wherein a phase difference between the first thermal-optic phase shifter and the second thermal-optic phase shifter in the same one of the optical waveguide branches, is linearly proportional to the common controlled voltage applied to the first thermal-optic phase shifter and the second thermal-optic phase shifter.