Patent ID: 11888531
Assignee: BEIJING ZHONGKE GUOGUANG QUANTUM TECHNOLOGY CO., LTD.
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 10:
11. The polarization independent DQPSK demodulation integrated optical chip according to claim 9, wherein the first optical waveguide is provided with a fifth polarization beam splitter rotator and a sixth polarization beam splitter rotator, the second optical waveguide is provided with a seventh polarization beam splitter rotator and an eighth polarization beam splitter rotator,
two output ports of the fifth polarization beam splitter rotator are respectively connected to two input ports of the sixth polarization beam splitter rotator through fifth optical waveguides to form a first equal arm interferometer; two output ports of the seventh polarization beam splitter rotator are respectively connected to two input ports of the eighth polarization beam splitter rotator through sixth optical waveguides to form a second equal arm interferometer;
a first polarization rotating optical waveguide is provided on each of seventh optical waveguides of four arms of the first equal arm interferometer and the second equal arm interferometer;
the first polarization rotating optical waveguide is composed of a first half wave plate optical waveguide and a first faraday rotatory waveguide, which are connected in sequence, an angle between a main axis direction of the first half wave plate optical waveguide and a horizontal direction is 22.5°, and a polarization rotation angle of the first faraday rotatory waveguide is 45°;
the first polarization rotating optical waveguide is configured to rotate polarization of an optical signal passing in a reverse direction by 90°, and maintain a polarization state of an optical signal passing in a forward direction unchanged;
the first equal arm interferometer is configured such that the first signal optical component incident from one of two input ports of the fifth polarization beam splitter rotator emits from an output port of the sixth polarization beam splitter rotator, and such that the first interference optical signal incident from the output port of the sixth polarization beam splitter rotator emits from one of the two input ports of the fifth polarization beam splitter rotator;
the second equal arm interferometer is configured such that the second signal optical component incident from one of two input ports of the seventh polarization beam splitter rotator emits from an output port of the eighth polarization beam splitter rotator, and such that the third interference optical signal incident from the output port of the eighth polarization beam splitter rotator emits from one of the two input ports of the seventh polarization beam splitter rotator.