CN-121978798-A - Stray light suppression device and stray light suppression structure for photonic chip

CN121978798ACN 121978798 ACN121978798 ACN 121978798ACN-121978798-A

Abstract

The invention relates to a stray light suppression device and a stray light suppression structure for a photonic chip, relates to the technical field of optical sensing, and solves the problems of signal-to-noise ratio reduction and the like caused by stray light crosstalk of a loop of the photonic chip. The stray light suppression device comprises a stray light suppressor and a stray light absorption layer, wherein the stray light suppressor comprises a first inverted cone waveguide, a straight waveguide and a vertical diffraction grating structure, the stray light absorption layer is arranged on the upper surface and the lower surface of a photon chip, the stray light absorption layer covers the vertical diffraction grating structure in the vertical direction, the first inverted cone waveguide and the straight waveguide are used for guiding stray light in the photon chip in a directional mode, the vertical diffraction grating structure is used for diffracting the stray light guided in the directional mode to the upper surface and the lower surface of the photon chip, and the stray light absorption layer is used for absorbing stray light diffracted and radiated in the photon chip.

Inventors

YUAN SHICHENG
MAO YUZHENG
YUAN JINMING
WAN XUAN
YUAN XUYANG
GE RUIXUAN
WU DAIXUAN

Assignees

中航捷锐(西安)光电技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A stray light suppression apparatus for a photonic chip, comprising: A stray light suppressor and a stray light absorbing layer; The stray light suppressor comprises a first inverted cone waveguide, a straight waveguide and a vertical diffraction grating structure, wherein the stray light absorbing layer is positioned on the upper surface and the lower surface of the photon chip, and the stray light absorbing layer covers the vertical diffraction grating structure in the vertical direction; The first inverted cone waveguide and the straight waveguide are used for guiding stray light in the photonic chip in a directional mode, the straight waveguide is a waveguide extending for a certain length along the widest part of the first inverted cone waveguide, the vertical diffraction grating structure is used for diffracting the stray light guided in a directional mode to the upper surface and the lower surface of the photonic chip, and the stray light absorbing layer is used for absorbing the stray light diffracted and radiated in the photonic chip.
2. The apparatus of claim 1, wherein the stray light suppressor further comprises: the second inverted cone waveguide and the third inverted cone waveguide are respectively positioned at two sides of the first inverted cone waveguide; The second inverted cone waveguide and the third inverted cone waveguide are used for converging stray light in the photon chip to the first inverted cone waveguide.
3. The apparatus of claim 2, wherein the first, second and third inverted cone waveguides are in a trigonal shape.
4. The device of claim 1, wherein the light absorbing material of the stray light absorbing layer is a metal or an absorbing glue.
5. A stray light suppression structure is characterized by being used for a multimode interference coupler in a photon chip, and comprises: at least one stray light suppression device for a photonic chip according to any one of claims 1 to 4, or at least one stray light suppression cascade structure, wherein the stray light suppression cascade structure comprises at least two cascaded stray light suppression devices for a photonic chip according to any one of claims 1 to 4; the at least one stray light suppression device or the at least one stray light suppression cascade structure is distributed on one side of the output straight waveguide of the multimode interference coupler.
6. The stray light suppressing structure according to claim 5, comprising: The stray light suppression devices or the stray light suppression cascade structures are symmetrically distributed on two sides of the output straight waveguide of the multimode interference coupler, and the stray light suppression devices or the stray light suppression cascade structures are distributed on one side of the output straight waveguide of the multimode interference coupler at inclination angles of 45 degrees, 30 degrees and 15 degrees respectively.
7. A stray light suppression structure is characterized by being used for a bending cascade polarizer in a photon chip, and comprises: at least one stray light suppression device for a photonic chip according to any one of claims 1 to 4, or at least one stray light suppression cascade structure, wherein the stray light suppression cascade structure comprises at least two cascaded stray light suppression devices for a photonic chip according to any one of claims 1 to 4; Wherein the at least one stray light suppression device or the at least one stray light suppression cascade structure is distributed along a tangential direction of a curved waveguide in the curved cascade polarizer.
8. A stray light suppression structure is characterized by being used for a conical end face coupler in a photon chip, and comprises: A stray light absorbing glue coating and at least one stray light suppressing device for a photonic chip according to any one of claims 1 to 4, or at least one stray light suppressing cascade structure, wherein the stray light suppressing cascade structure comprises at least two cascade-connected stray light suppressing devices for a photonic chip according to any one of claims 1 to 4, wherein the stray light absorbing glue coating is located on upper and lower surfaces of the photonic chip and the stray light absorbing glue coating covers tapered end surfaces of the tapered end surface coupler in a vertical direction; Wherein the at least one stray light suppression device or the at least one stray light suppression cascade structure is distributed on both sides of the tapered end face coupler.
9. A stray light suppression structure is characterized by being used for a blank area in a photon chip, and comprises: at least one stray light suppression device for a photonic chip according to any one of claims 1 to 4, or at least one stray light suppression cascade structure, wherein the stray light suppression cascade structure comprises at least two cascaded stray light suppression devices for a photonic chip according to any one of claims 1 to 4; wherein the at least one stray light suppression device or the at least one stray light suppression cascade structure is arranged in a regular pattern.
10. The stray light suppression structure of claim 9, wherein the regular pattern is circular or rectangular.

Description

Stray light suppression device and stray light suppression structure for photonic chip Technical Field The invention relates to the technical field of optical sensing, in particular to a stray light suppression device and a stray light suppression structure for a photonic chip. Background The photonic chip is generally composed of an active device and a passive device, and uses an optical waveguide as a core transmission medium to realize functions of transmission, beam splitting, coupling, modulation and the like of optical signals. Photonic chips have been widely used in the fields of optical sensing, optical communication, optical computing, etc. because of their high integration, mass production, low cost, and low power consumption. However, with the rapid development of unmanned, artificial intelligence, quantum computing and other emerging technologies, stringent requirements are put on the performance, precision and stability of the photonic chip. In the existing photon chip structure, key elements such as an optical beam splitter, a bending cascade polarizer, an end surface coupler and the like are easy to generate stray light in the working process, and the crosstalk phenomenon between on-chip optical paths is caused. The stray light interference not only reduces the signal to noise ratio of signals, but also can cause signal distortion of output signals of the photon chip, and seriously affects the overall performance and reliability of the system. At present, an efficient and feasible method for effectively inhibiting the problems is not available. Therefore, how to propose and design a feasible stray light suppression scheme becomes a technical problem to be solved in order to realize a high-performance and high-precision photon chip, and further popularization and development of the photon chip in a high-end application scene are also greatly affected. Disclosure of Invention In view of the above analysis, the present invention aims to provide a stray light suppression device and a stray light suppression structure for a photonic chip, which are used for solving the problems of signal-to-noise ratio reduction and the like caused by stray light crosstalk of a photonic chip loop. In a first aspect, an embodiment of the present invention provides a stray light suppression apparatus for a photonic chip, including: A stray light suppressor and a stray light absorbing layer; The stray light suppressor comprises a first inverted cone waveguide, a straight waveguide and a vertical diffraction grating structure, wherein the stray light absorbing layer is positioned on the upper surface and the lower surface of the photon chip, and the stray light absorbing layer covers the vertical diffraction grating structure in the vertical direction; The first inverted cone waveguide and the straight waveguide are used for guiding stray light in the photonic chip in a directional mode, the straight waveguide is a waveguide extending for a certain length along the widest part of the first inverted cone waveguide, the vertical diffraction grating structure is used for diffracting the stray light guided in a directional mode to the upper surface and the lower surface of the photonic chip, and the stray light absorbing layer is used for absorbing the stray light diffracted and radiated in the photonic chip. Based on a further improvement of the above device, the stray light suppressor further comprises: the second inverted cone waveguide and the third inverted cone waveguide are respectively positioned at two sides of the first inverted cone waveguide; The second inverted cone waveguide and the third inverted cone waveguide are used for converging stray light in the photon chip to the first inverted cone waveguide. Based on a further development of the above device, the first, second and third inverted cone waveguides are in the form of a trigeminal shape. Based on the further improvement of the device, the light absorbing material of the stray light absorbing layer is metal or absorbing glue. In a second aspect, an embodiment of the present invention provides a stray light suppressing structure, including: at least one stray light suppression device for a photonic chip according to any one of the first aspects of the invention, or at least one stray light suppression cascade structure, wherein the stray light suppression cascade structure comprises at least two cascade connected stray light suppression devices for a photonic chip according to any one of the first aspects of the invention; the at least one stray light suppression device or the at least one stray light suppression cascade structure is distributed on one side of the output straight waveguide of the multimode interference coupler. Based on the further improvement of the stray light suppressing structure, the method comprises the following steps: The stray light suppression devices or the stray light suppression cascade structures are symmetrically distribu