Patent ID: 11949461
Assignee: BEIJING ZHONGKE GUOGUANG QUANTUM TECHNOLOGY CO., LTD.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. The integrated self-coherent receiving optical chip based on round-trip delay interferometers according to claim 1, wherein the first round-trip delay interferometer comprises a ninth polarization beam splitting rotator, a thirteenth optical waveguide, a fourteenth optical waveguide, a first polarization beam splitter and a fifteenth optical waveguide,
wherein, the fifteenth optical waveguide has a length equal to an arm length difference of the first round-trip delay interferometer;
the second round-trip delay interferometer comprises a tenth polarization beam splitting rotator, a sixteenth optical waveguide, a seventeenth optical waveguide, a second polarization beam splitter, an eighteenth optical waveguide and a third quarter-wave plate,
the eighteenth optical waveguide has a length equal to an arm length difference of the second round-trip delay interferometer;
an angle between a main axis of the third quarter-wave plate and a horizontal direction is 0°;
a first notch groove is provided transversely through the thirteenth optical waveguide, the fourteenth optical waveguide, the sixteenth optical waveguide, and the seventeenth optical waveguide; a first half-wave plate is inserted into the first notch groove, and an angle between a main axis of the first half-wave plate and the horizontal direction is 22.5°;
the ninth polarization beam splitting rotator is configured to perform a polarization beam splitting on the first signal light component to generate a first polarization beam splitting component and a second polarization beam splitting component;
the tenth polarization beam splitting rotator is configured to perform a polarization beam splitting on the second signal light component to generate a third polarization beam splitting component and a fourth polarization beam splitting component;
the first half-wave plate is configured to rotate a polarization state of a passing optical signal by 45°;
the first polarization beam splitter is configured to transmit a horizontal polarization component of a first polarization beam splitting component incident from a first input port of the first polarization beam splitter to the fifteenth optical waveguide and reflect a vertical polarization component of the first polarization beam splitting component incident from the first input port of the first polarization beam splitter to the fifteenth optical waveguide, so that both of the horizontal polarization component and the vertical polarization component of the first polarization beam splitting component incident from the first input port of the first polarization beam splitter are output from a second input port of the first polarization beam splitter for a polarization combination to generate a first polarization synthesized optical signal; and configured to transmit a horizontal polarization component of a second polarization beam splitting component incident from the second input port of the first polarization beam splitter to the fifteenth optical waveguide and reflect a vertical polarization component of the second polarization beam splitting component incident from the second input port of the first polarization beam splitter to the fifteenth optical waveguide, so that both of the horizontal polarization component and the vertical polarization component of the second polarization beam splitting component incident from the second input port of the first polarization beam splitter are output from the first input port of the first polarization beam splitter for a polarization combination to generate a second polarization synthesized optical signal;
the second polarization beam splitter is configured to transmit a horizontal polarization component of a third polarization beam splitting component incident from a first input port of the second polarization beam splitter to the sixteenth optical waveguide and reflect a vertical polarization component of the third polarization beam splitting component incident from the first input port of the second polarization beam splitter to the sixteenth optical waveguide, so that both of the horizontal polarization component and the vertical polarization component of the third polarization beam splitting component incident from the first input port of the second polarization beam splitter are output from a second input port of the second polarization beam splitter for a polarization combination to generate a third polarization synthesized optical signal; and configured to transmit a horizontal polarization component of the fourth polarization beam splitting component incident from a second input port of the second polarization beam splitter to the sixteenth optical waveguide and reflect a vertical polarization component of the fourth polarization beam splitting component incident from the second input port of the second polarization beam splitter to the sixteenth optical waveguide, so that both of the horizontal polarization component and the vertical polarization component of the fourth polarization beam splitting component incident from the second input port of the second polarization beam splitter are output from the first input port of the second polarization beam splitter for a polarization combination to generate a fourth polarization synthesized optical signal;
the third quarter-wave plate is configured to increase the vertical polarization component of the third polarization beam splitting component and the vertical polarization component of the fourth polarization beam splitting component passing through the third quarter-wave plate by π/2 phase;
the ninth polarization beam splitting rotator is further configured to perform a polarization beam combining on a horizontal polarization component of the first polarization synthesized optical signal and a horizontal polarization component of the second polarization synthesized optical signal to generate the first interference optical signal; and perform a polarization beam combining on a vertical polarization component of the first polarization synthesized optical signal and a vertical polarization component of the second polarization synthesized optical signal to generate the second interference optical signal; and
the tenth polarization beam splitting rotator is configured to perform a polarization beam combining on a horizontal polarization component of the third polarization synthesized optical signal and a horizontal polarization component of the fourth polarization synthesized optical signal to generate the third interference optical signal; and perform a polarization beam combining on a vertical polarization component of the third polarization synthesized optical signal and a vertical polarization component of the fourth polarization synthesized optical signal to generate the fourth interference optical signal.