Integrated polarization detection grating structure in infrared detection chip

Abstract

This invention discloses an integrated polarization detection grating structure in an infrared detection chip. The infrared detection chip includes an absorption layer with multiple pixels. Each pixel is covered by a linear polarization grating unit. Each linear polarization grating unit includes a main grating block and several sub-grating blocks. The sub-grating blocks surround the main grating block, and each sub-grating block has multiple uniformly parallel linear gratings. Different sub-grating blocks within the same linear polarization grating unit have linear gratings with different angles. The main grating block has several uniformly spaced annular gratings, all of which are concentrically arranged. The integrated polarization detection grating structure in the infrared detection chip of this invention increases the effective absorption area of ​​the absorption layer and improves the optical responsivity and polarization sensitivity of the infrared detection chip.

Description

Technical Field

[0001] This invention belongs to the field of grating structure technology, specifically relating to an integrated polarization detection grating structure in an infrared detection chip. Background Technology

[0002] Infrared detectors have been widely used, and in recent years, higher demands have been placed on their detection and recognition capabilities, urgently requiring innovative development. The rapid advancement of microelectronics technology has made it possible to integrate multi-functional chips onto infrared detectors, providing a foundation for innovation. In existing quantum well in-process (QWIP) infrared detectors, two-dimensional gratings are the mainstream technology used by most manufacturers, and 2D grating coupling is currently the most widely used coupling method, with the grating repeating periodically in two perpendicular directions on the detector surface. However, due to the inherent characteristics of 2D grating coupling, this type of grating is selective for the detection wavelength, thus limiting the broadband and polychromatic detection performance of infrared detectors. In patent application CN201821426985.4, the inventors disclosed a linear polarization grating structure for infrared detector chips, specifically a grating structure where different grating blocks in the same linear polarization grating unit have different angles. This novel grating structure can adapt to light with different incident angles during use, improving the optical responsivity and polarization sensitivity of the infrared detector. However, this structure has certain limitations in light absorption. For example, when the incident light has a certain angle, only one grating block in each linear polarization grating unit can fully function, while the remaining grating blocks have little effect. Only 25% of the entire absorption layer can absorb light, and most areas cannot play their due role, thus limiting its optical responsivity and polarization sensitivity. Therefore, in order to further improve the optical responsivity and polarization sensitivity of the infrared detector chip, it is necessary to further improve the above-mentioned grating structure. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an integrated polarization detection grating structure in an infrared detection chip. The infrared detection chip includes an absorption layer with multiple pixels. Each pixel is covered with a linear polarization grating unit. Each linear polarization grating unit includes a main grating block and several sub-grating blocks. The sub-grating blocks surround the main grating block. Each sub-grating block has multiple uniformly parallel linear gratings. Different sub-grating blocks in the same linear polarization grating unit have linear gratings with different angles. The main grating block has several uniformly spaced annular gratings. All annular gratings on the main grating block are concentrically arranged.

[0004] As a preferred embodiment of the above technical solution, the infrared detection chip is a type II superlattice infrared detection chip.

[0005] As a preferred embodiment of the above technical solution, each of the linear polarization grating units includes four sub-grating blocks of equal size. The sub-grating blocks are equal in size to the main grating block. The main grating block includes four vertical edges connected in sequence. The four sub-grating blocks are respectively connected to one vertical edge of the main grating block.

[0006] As a preferred embodiment of the above technical solution, each linear polarization grating unit includes a first sub-grating block, a second sub-grating block, a third sub-grating block, and a fourth sub-grating block. The first sub-grating block, the second sub-grating block, the third sub-grating block, and the fourth sub-grating block are located above, below, to the left, and to the right of the main grating block, respectively. The linear gratings on the second sub-grating block form a 45-degree angle with the linear gratings on the first sub-grating block, the linear gratings on the third sub-grating block form a 45-degree angle with the linear gratings on the second sub-grating block, the linear gratings on the fourth sub-grating block form a 45-degree angle with the linear gratings on the third sub-grating block, the linear gratings on the first sub-grating block form a 90-degree angle with the linear gratings on the third sub-grating block, and the linear gratings on the second sub-grating block form a 90-degree angle with the linear gratings on the fourth sub-grating block.

[0007] As a preferred embodiment of the above technical solution, adjacent linear polarization grating units share two sub-grating blocks.

[0008] The beneficial effects of the present invention are: the integrated polarization detection grating structure in the infrared detection chip of the present invention increases the effective absorption area of ​​the absorption layer and improves the optical responsivity and polarization sensitivity of the infrared detection chip. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0010] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0012] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0013] like Figure 1 As shown, the infrared detector chip features an integrated polarization detection grating structure. The chip includes an absorption layer with multiple pixels. Each pixel is covered by a linear polarization grating unit. Each linear polarization grating unit includes a main grating block 1 and several sub-grating blocks. The sub-grating blocks surround the main grating block 1, and each sub-grating block has multiple uniformly parallel linear gratings 3. Different sub-grating blocks within the same linear polarization grating unit have linear gratings 3 with different angles. The main grating block 1 has several uniformly spaced annular gratings 4, all concentrically arranged. The annular gratings 4 on the main grating block 1 can absorb light at any angle, assisting the linear gratings 3 on the sub-grating blocks designed for absorbing light at specific angles, thereby improving the overall optical responsivity and polarization sensitivity of the device.

[0014] Furthermore, the infrared detection chip is a type II superlattice infrared detection chip.

[0015] Furthermore, each of the linear polarization grating units includes four sub-grating blocks of equal size, the sub-grating blocks being the same size as the main grating block 1, the main grating block 1 including four vertical edges 5 connected in sequence, and the four sub-grating blocks being respectively connected to one vertical edge 5 of the main grating block 1.

[0016] Furthermore, each of the linear polarization grating units includes a first sub-grating block 6, a second sub-grating block 7, a third sub-grating block 8, and a fourth sub-grating block 9. The first sub-grating block 6, the second sub-grating block 7, the third sub-grating block 8, and the fourth sub-grating block 9 are located on the upper side, lower side, left side, and right side of the main grating block 1, respectively. The linear grating 3 on the second sub-grating block 7 forms a 45-degree angle with the linear grating 3 on the first sub-grating block 6, the linear grating 3 on the third sub-grating block 8 forms a 45-degree angle with the linear grating 3 on the second sub-grating block 7, and the linear grating 3 on the fourth sub-grating block 9 forms a 45-degree angle with the linear grating 3 on the third sub-grating block 8. The linear grating 3 on the first sub-grating block 6 forms a 90-degree angle with the linear grating 3 on the third sub-grating block 8, and the linear grating 3 on the second sub-grating block 7 forms a 90-degree angle with the linear grating 3 on the fourth sub-grating block 9. The four sub-grating blocks are designed for incident light at specific angles, thereby enhancing the absorption layer's ability to absorb light at those specific angles.

[0017] Furthermore, adjacent linear polarization grating units share two sub-grating blocks. This increases the light efficiency of the absorption region under illumination from any direction, increases the effective area of ​​the absorption region, and improves the overall sensitivity.

[0018] It is worth mentioning that other structural and other technical features of the infrared detection chip involved in this patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0019] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experimentation on the basis of the prior art should be within the scope of protection defined by the claims.

Claims

1. An integrated polarization detection grating structure in an infrared detection chip, characterized in that, The infrared detection chip comprises an absorption layer, a plurality of pixels are arranged on the absorption layer, each pixel is covered by a linear polarization grating unit, each linear polarization grating unit comprises a main grating block and a plurality of auxiliary grating blocks, the auxiliary grating blocks are arranged around the main grating block, each auxiliary grating block is provided with a plurality of linear gratings arranged in parallel, the linear gratings of different auxiliary grating blocks in the same linear polarization grating unit have different angles, the main grating block is provided with a plurality of annular gratings arranged in parallel, and all the annular gratings on the main grating block are arranged in a concentric manner.

2. The integrated polarization detection grating structure in an infrared detection chip as claimed in claim 1, wherein, The infrared detection chip is a type II superlattice infrared detection chip.

3. The integrated polarization detection grating structure in an infrared detection chip of claim 2, wherein, Each linear polarization grating unit comprises four auxiliary grating blocks of equal size, the auxiliary grating blocks are equal in size to the main grating block, and the main grating block comprises four vertical edges connected in sequence, and the four auxiliary grating blocks are connected to one vertical edge of the main grating block.

4. The integrated polarization detection grating structure in an infrared detection chip of claim 3, wherein, Each linear polarization grating unit comprises a first auxiliary grating block, a second auxiliary grating block, a third auxiliary grating block and a fourth auxiliary grating block, the first auxiliary grating block, the second auxiliary grating block, the third auxiliary grating block and the fourth auxiliary grating block are arranged on the upper side, the lower side, the left side and the right side of the main grating block respectively, the linear gratings on the second auxiliary grating block and the first auxiliary grating block form an angle of 45 degrees, the linear gratings on the third auxiliary grating block and the second auxiliary grating block form an angle of 45 degrees, the linear gratings on the fourth auxiliary grating block and the third auxiliary grating block form an angle of 45 degrees, the linear gratings on the first auxiliary grating block and the third auxiliary grating block form an angle of 90 degrees, and the linear gratings on the second auxiliary grating block and the fourth auxiliary grating block form an angle of 90 degrees.

5. The integrated polarization detection grating structure in an infrared detection chip of claim 4, wherein, Two auxiliary grating blocks of adjacent linear polarization grating units are shared.

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