WO2023185915A1

WO2023185915A1 - Polarization imaging sensor and electronic apparatus

Info

Publication number: WO2023185915A1
Application number: PCT/CN2023/084659
Authority: WO
Inventors: 周常毅
Original assignee: 维沃移动通信有限公司
Priority date: 2022-04-02
Filing date: 2023-03-29
Publication date: 2023-10-05
Also published as: CN114843298A

Abstract

The present application discloses a polarization imaging sensor and an electronic apparatus. The polarization imaging sensor comprises a super-structure lens and a photoelectric device. The super-structure lens decomposes first incident light into first polarization-state light and second polarization-state light, the polarization angle of the first polarization-state light being different from that of the second polarization-state light. The photoelectric device comprises a first photoelectric unit and a second photoelectric unit. The first polarization-state light is incident on the first photoelectric unit, and the second polarization-state light is incident on the second photoelectric unit.

Description

Polarization imaging sensors and electronic equipment

Cross-references to related applications

This application claims priority to Chinese patent application 202210352934.6 filed on April 2, 2022, the entire content of which is incorporated herein by reference.

Technical field

The present application belongs to the technical field of electronic products, and specifically relates to a polarization imaging sensor and electronic equipment having the polarization imaging sensor.

Background technique

Traditional image sensors can usually only sense some parameters of light, such as brightness, color and propagation direction of light, but cannot record the polarization characteristics of light. The polarization imaging sensor can visualize the polarization characteristics of light (light wave vibration direction) that are invisible to the human eye, enriching application scenarios.

Existing polarization imaging sensors usually consist of polarization filters, microlenses and photodiodes. Among them, polarization filters are usually made of gratings processed from metal into linear slits, which can only allow the transmission of light in a certain vector vibration direction. light, and absorb (or reflect) the light that vibrates perpendicular to it. In order to make the polarization imaging sensor have a high extinction ratio, the polarization filter used will greatly reduce the light transmittance of the pixel, making it difficult to balance the extinction ratio and light transmittance characteristics of the polarization filter.

Contents of the invention

This application aims to provide a polarization imaging sensor and electronic equipment that can at least solve the problem that polarization imaging sensors in the prior art cannot take into account both the extinction ratio and the light transmittance at the same time.

In order to solve the above technical problems, this application is implemented as follows:

In a first aspect, embodiments of the present application provide a polarization imaging sensor, including:

Meta-lens, which decomposes the first incident light into a first polarized state light and a second polarized state light Light, the polarization angle of the first polarized light is different from the polarization angle of the second polarized light;

An optoelectronic device includes a first optoelectronic unit and a second optoelectronic unit. The first polarized light is incident on the first optoelectronic unit, and the second polarized light is incident on the second optoelectronic unit.

In a second aspect, embodiments of the present application provide an electronic device, including the polarization imaging sensor in the above embodiment.

In the embodiment of the present application, by designing a metalens and an optoelectronic device, instead of the design of a polarizing filter, the metalens can vectorially decompose the first incident light into first polarized light with different polarization angles and The second polarized light, the decomposed first polarized light and the second polarized light with different polarization angles can be respectively focused on the first photoelectric unit and the second photoelectric unit of the optoelectronic device to ensure the extinction ratio of the polarization imaging sensor. At the same time, it effectively improves the light transmittance.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1 is a schematic structural diagram of a polarization imaging sensor according to an embodiment of the present invention;

Figure 2 is an exploded schematic diagram of a polarization imaging sensor according to an embodiment of the present invention;

Figure 3 is a cross-sectional view of a polarization imaging sensor according to an embodiment of the present invention;

Figure 4 is another cross-sectional view of a polarization imaging sensor according to an embodiment of the present invention;

Figure 5 is a schematic structural diagram of a metalens of a polarization imaging sensor according to an embodiment of the present invention;

Figure 6 is a schematic structural diagram of a microlens of a polarization imaging sensor according to an embodiment of the present invention;

Figure 7 is a schematic diagram of a light path of a polarization imaging sensor according to an embodiment of the present invention;

Figure 8 is a schematic diagram of another light path of a polarization imaging sensor according to an embodiment of the present invention;

Figure 9 is another schematic diagram of a light path of a polarization imaging sensor according to an embodiment of the present invention;

Figure 10 is a schematic diagram of another light path of a polarization imaging sensor according to an embodiment of the present invention;

Figure 11 is a polarization angle diagram corresponding to each pixel of the polarization imaging sensor according to Embodiment 1 of the present invention;

Figure 12 is a partial enlarged view of area A in Figure 11;

Figure 13 is a polarization angle diagram of each pixel of the polarization imaging sensor according to Embodiment 2 of the present invention;

Figure 14 is a partial enlarged view of area B in Figure 8;

Figure 15 is a graph showing the change of light intensity with the polarization angle of incident light according to the polarization imaging sensor according to Embodiment 1 of the present invention;

Figure 16 is an electric field distribution diagram of 0° polarized light incident on the second lens unit in the polarized imaging sensor according to Embodiment 1 of the present invention;

Figure 17 is an electric field distribution diagram of 90° polarized light incident on the second lens unit in the polarized imaging sensor according to Embodiment 1 of the present invention;

Figure 18 is an electric field distribution diagram of 0° polarized light incident on the second lens unit in the polarized imaging sensor according to Embodiment 2 of the present invention;

Figure 19 is an electric field distribution diagram of 90° polarized light incident on the second lens unit in the polarized imaging sensor according to Embodiment 2 of the present invention.

Reference signs:
Polarization imaging sensor 100;
Metalens 10; microlens 11; first lens unit 111; second lens unit 112; third lens unit 113; fourth lens unit 114;
Optoelectronic device 20; first optoelectronic unit 21; second optoelectronic unit 22; third optoelectronic unit 23; fourth optoelectronic unit 24;
Fixed layer 30;
Filling layer 40;
first incident light 51; second incident light 52;
The first polarized light 61; the second polarized light 62.

Detailed ways

Embodiments of the present invention will be described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

The terms "first" and "second" features in the description and claims of this application may include one or more of these features, either explicitly or implicitly. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and/or" in the description and claims indicates at least one of the connected objects, and the character "/" generally indicates that the related objects are in an "or" relationship.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis", The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply the referred devices or components. Must have a specific orientation, be constructed and operate in a specific orientation and are therefore not to be construed as limitations of the invention.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In conjunction with the accompanying drawings, the following describes the preferred embodiments of the present application through specific embodiments and application scenarios. The vibration imaging sensor 100 will be described in detail.

As shown in FIGS. 1 to 10 , a polarization imaging sensor 100 according to an embodiment of the present invention includes a metalens 10 and an optoelectronic device 20 .

Specifically, the metalens 10 decomposes the first incident light 51 into a first polarized light 61 and a second polarized light 62. The polarization angle of the first polarized light 61 is different from the polarization angle of the second polarized light 62. . The optoelectronic device 20 includes a first optoelectronic unit 21 and a second optoelectronic unit 22. The first polarized light 61 is incident on the first optoelectronic unit 21, and the second polarized light 62 is incident on the second optoelectronic unit 22.

In other words, referring to FIGS. 1 and 2 , the polarization imaging sensor 100 according to the embodiment of the present invention mainly consists of a metalens 10 and an optoelectronic device 20 . Among them, the metalens 10 (metalens, ML) can focus the light beam and arbitrarily control the amplitude, phase and polarization of the light. After the light beams with different polarization directions are converged to the metalens 10 , the converged light beam is vector decomposed through the metalens 10 . Among them, assuming that the propagation direction of light is z, it is set that when the polarization direction of the light is consistent with the x direction, it is 0° polarized light, when it is consistent with the y direction, it is 90° polarized light, and the polarization direction is at a certain angle with the x or y direction. Other light rays can be vector decomposed and converted into small polarized light in the x and y directions through the metalens 10 .

Referring to FIGS. 7 and 9 , when the first incident light 51 enters the metalens 10 , the metalens 10 can decompose the first incident light 51 into a first polarized light 61 and a second polarized light 62 . The polarization angle of the first polarized light 61 is different from the polarization angle of the second polarized light 62 (α and β in FIG. 9 respectively represent polarization angles). The first polarized light can be understood as the polarized light in the x direction, and the second polarized light can be understood as the polarized light in the y direction. Referring to FIG. 10 , the difference between the polarization angle of the first polarized light 61 and the polarization angle of the second polarized light 62 is 90°. The first polarized light decomposed by the first incident light 51 may be incident on the first photoelectric unit 21 of the optoelectronic device 20 . The second polarized light decomposed by the first incident light 51 may be incident on the second photoelectric unit 22 of the optoelectronic device 20 . By making the vector-decomposed light beams of the meta-lens 10 incident on the first photovoltaic unit 21 and the second photovoltaic unit 22 respectively, it is beneficial to make full use of the light beams with different polarization directions and ensure that the light beams with different polarization directions can all be incident after decomposition. The optoelectronic device 20 can not only ensure the extinction ratio, but also greatly improve the light transmittance.

Therefore, according to the polarization imaging sensor 100 according to the embodiment of the present invention, by designing the optoelectronic device 20 And the meta-lens 10 replaces the design of the polarizing filter. The meta-lens 10 can vectorially decompose the converged light beams with different polarization angles. The decomposed light beams can all be focused on the optoelectronic device 20 to ensure that the polarized imaging sensor 100 While improving the extinction ratio, it effectively improves the light transmittance and light utilization, and improves the performance of the sensor.

According to an embodiment of the present invention, the second incident light 52 passes through the metalens 10 and then enters the first photovoltaic unit 21 , and the polarization angle of the second incident light 52 is the same as the polarization angle of the first polarized light 61 . The polarization angle of the second incident light 52 is different from the polarization angle of the first incident light 51 . The first photoelectric unit 21 receives and records the first polarized light 61 decomposed by the first incident light 51 after passing through the metalens 10 and the second incident light 52 after passing through the metalens 10 .

That is to say, as shown in FIGS. 8 and 9 , when the second incident light 52 enters the metalens 10 , the polarization angle of the second incident light 52 is the same as the polarization angle of the first polarized light 61 . The polarization angle of the incident light 52 is different from the polarization angle of the first incident light 51 . Since the polarization angle of the second incident light 52 is the same as the polarization angle of the first polarized light 61 , the second incident light 52 directly passes through the metalens and is incident on the first photovoltaic unit. The first photoelectric unit 21 can receive and record the first polarized light 61 decomposed by the first incident light 51 after passing through the metalens 10 and the second incident light 52 after passing through the metalens 10, thereby ensuring polarization imaging. The sensor 100 can make full use of light beams with other polarization directions, so that the light beams with different polarization directions can all be focused on the optoelectronic device 20 after being decomposed.

Embodiments of the present application not only allow the required incident polarized light to be converged to the corresponding optoelectronic unit, but also the remaining incident polarized light with undesired polarization angles that was originally eliminated in the prior art can also be converged to the corresponding photovoltaic unit through vector decomposition. The photoelectric unit not only ensures the extinction ratio, but also greatly improves the light transmittance.

According to an embodiment of the present invention, as shown in FIGS. 2 and 5 , the metalens 10 mainly consists of a first lens unit 111 and a second lens unit 112 . Among them, the first lens unit 111 is arranged opposite to the first photoelectric unit 21 , and the second lens unit 112 is arranged opposite to the second photoelectric unit 22 . The first lens unit 111 and the first photoelectric unit 21 may correspond to each other in the height direction (z direction), and the second lens unit 112 and the second photoelectric unit 22 may also correspond to each other in the height direction. first incident light After passing through the first lens unit 111, it is decomposed into the first polarized light 61 and the second polarized light 62 by the first lens unit 111. The first polarized light 61 is incident on the first photoelectric unit 21 , and the second polarized light 62 is incident on the second photoelectric unit 22 . Similarly, after the first incident light 51 passes through the second lens unit 112, it will also be decomposed into the first polarized light 61 and the second polarized light 62 by the second lens unit 112. The first polarized light 61 is incident on the first photoelectric unit 21 , and the second polarized light 62 is incident on the second photoelectric unit 22 .

Referring to Figure 5, Figure 12 and Figure 13, both the first lens unit 111 and the second lens unit 112 include a plurality of microlenses 11, and the plurality of microlenses 11 in the second lens unit 112 are relative to the corresponding positions in the first lens unit 111. The microlens 11 is deflected by a first angle (θ represents the first angle in Figure 5, Figure 12 and Figure 14). The angle difference between the polarization angle of the first polarized light 61 and the polarization angle of the second polarized light 62 is equal to the first angle.

In this application, as shown in FIGS. 5 and 6 , each microlens 11 can be designed as a nanocolumn, and each nanocolumn in the second lens unit 112 corresponds to each nanocolumn in the first lens unit 111 . . At the same time, each nanocolumn in the second lens unit 112 is deflected by a first angle (see the θ angle in FIG. 5 ) with a corresponding nanocolumn in the first lens unit 111 . The difference between the polarization angle of the first polarized light 61 and the polarization angle of the second polarized light 62 is equal to the first angle.

As shown in Figures 11 and 12, the first angle may be 0°, 45°, 90° or 135°. For example, when the polarization angle of the first polarized light 61 is 90° and the polarization angle of the second polarized light 62 is 0°, at this time, as shown in FIG. 10 , the first polarized light 61 passes through the first lens. When unit 111 is connected, it can be focused on the first photoelectric unit 21 in the main axis direction (height direction) of the first lens unit 111. When the second polarized light 62 passes through the first lens unit 111, it can be focused on the third photoelectric unit 21 on the side. On the second photovoltaic unit 22. Similarly, referring to FIG. 10 , when the second polarized light 62 passes through the second lens unit 112 , it can be focused on the second photoelectric unit 22 in the main axis direction of the second lens unit 112 , and the first polarized light 61 passes through the second photoelectric unit 22 in the main axis direction of the second lens unit 112 . When the second lens unit 112 is used, it can focus on the first photoelectric unit 21 on the side.

As a result, the degree and direction of polarization can be calculated through the light intensity information recorded by each photoelectric unit, which is beneficial to achieve tasks that are difficult for traditional image sensors, such as object shape recognition, elimination of interfering reflected light on water or glass surfaces, and deformation. and scratch detection, etc., providing more abundant application fields for electronic equipment scene and expand the application scope of imaging technology.

In some specific embodiments of the present invention, the metalens 10 includes a plurality of microlenses 11 , and the length, width, height or extension direction of the sides of the plurality of microlenses 11 are different.

In other words, as shown in Figures 2 and 5, the metalens 10 includes a plurality of microlenses 11, each microlens can be configured as a nano-column, and the multiple nano-column microlenses 11 can be arranged in an array. The length, width, height or extending direction of the sides of the plurality of microlenses 11 may be different. When the height (H) of the anisotropic microlens 11 is constant, the structural parameters of the nanocolumn (microlens 11) can be adjusted, such as the length (L), width (W) and the setting angle of the microlens. etc., different equivalent refractive indices can be provided for 0° polarized light and 90° polarized light, and the sum of the phase retardations along the fast and slow axes of each microlens 11 will result in a phase profile that is sensitive to linear polarization, and thus Achieve polarization multiplexing. It should be noted that in the drawings of this application, x, y, and z respectively represent three-dimensional directions, which can be understood and implemented by those skilled in the art, and will not be described in detail in this application.

According to an embodiment of the present invention, as shown in Figures 2 and 5, the metalens 10 includes a first lens unit 111 and a second lens unit 112. The first lens unit 111 is arranged opposite to the first photoelectric unit 21, and the second lens unit 111 is disposed opposite to the first photoelectric unit 21. The lens unit 112 is arranged opposite to the second photoelectric unit 22 . Both the first lens unit 111 and the second lens unit 112 include a plurality of microlenses 11 , and each microlens in the second lens unit 112 is rotated by the same angle relative to its own axis as each microlens in the first lens unit 111 . Among them, each micro lens 11 in the first lens unit 111 is compared with each micro lens 11 in the second lens unit 112. One of the two corresponding micro lenses 11 can rotate relative to one of the micro lenses 11. 0°, 45°, 90° or 135°, so that the first lens unit 111 and the second lens unit can focus the polarized light of 0°, 45°, 90° and 135° according to the different polarization directions of the incident light. On the corresponding different photoelectric units, it is ensured that the light of different polarization states after the incident light vector is decomposed can be focused on the corresponding photoelectric units, thereby effectively improving the light transmittance while ensuring the extinction ratio of the polarization imaging sensor 100 .

In this application, as shown in FIGS. 2 and 10 , each lens unit in the metalens 10 and each optoelectronic unit in the optoelectronic device 20 completely correspond in the height direction (z direction), and together form an image. Yuan. Each lens unit can convert 0°, 45°, 90°, respectively according to the different polarization directions of the incident light. and 135° polarized light are focused onto different corresponding photoelectric units. The degree and direction of polarization can be calculated through the light intensity information recorded by different photoelectric units, which is conducive to achieving tasks that are difficult to achieve with traditional image sensors, such as object shape recognition. , eliminate interfering reflected light, deformation and scratch detection on water or glass surfaces, etc., provide more abundant application scenarios for electronic devices, and expand the application scope of imaging technology.

According to an embodiment of the present invention, as shown in FIGS. 2 and 5 , the metalens 10 includes a first lens unit 111 and a second lens unit 112 . The first lens unit 111 is arranged opposite to the first photoelectric unit 21 , and the second lens unit 112 is arranged opposite to the second photoelectric unit 22 . Each of the first lens unit 111 and the second lens unit 112 includes a plurality of microlenses 11 . The plurality of microlenses 11 in the first lens unit 111 and the second lens unit 112 are respectively distributed in an array. Referring to FIGS. 11 and 12 , the microlenses 11 in the nth row and mth column in the first lens unit 111 and the microlenses 11 in the nth row and mth column in the second lens unit 112 are symmetrical to each other. Among them, n≥1, m≥1. In this way, the polarized light with different polarization angles is focused on the corresponding different photoelectric units, which is conducive to making full use of the light beams with different polarization directions, ensuring that the light beams with different polarization directions can all be focused on the photoelectric device 20 after being decomposed, effectively improving the extinction At the same time, it can also greatly improve the light transmittance.

In some specific implementations of the present invention, as shown in FIGS. 13 and 14 , the first lens unit 111 and the second lens unit 112 are distributed diagonally. The plurality of microlenses 11 in the first lens unit 111 and the second lens unit 112 are respectively distributed in an array. The microlenses 11 in the nth row and mth column in the first lens unit 111 rotate at a first angle relative to the microlenses 11 in the nth row and mth column in the second lens unit 112, where n≥1 and m≥1. Among them, the first angle can be 45° or 90°, thereby focusing the polarized light of different polarization angles onto different corresponding photoelectric units, which is conducive to making full use of the light beams of different polarization directions and ensuring that the light beams of different polarization directions are decomposed Finally, it can all be focused on the optoelectronic device 20, which not only effectively improves the extinction ratio, but also greatly improves the light transmittance.

According to an embodiment of the present invention, as shown in FIGS. 2 and 5 , the metalens 10 includes a first lens unit 111 , a second lens unit 112 , a third lens unit 113 and a fourth lens unit 114 . The first lens unit 111 , the second lens unit 112 , the third lens unit 113 and the fourth lens unit 114 roughly correspond to the range of each dotted circle in FIG. 5 .

As shown in FIG. 5 , the first lens unit 111 , the second lens unit 112 , the third lens unit 113 and the fourth lens unit 114 each include a plurality of microlenses 11 . 11 and 12 , the plurality of microlenses 11 in the first lens unit 111 , the second lens unit 112 , the third lens unit 113 and the fourth lens unit 114 are respectively distributed in an array, and the first lens unit 111 and the fourth lens unit 114 are arranged diagonally. The first lens unit 111 and the second lens unit 112 are arranged in the horizontal direction.

As shown in FIG. 12 , the microlenses 11 in the nth row and mth column in the first lens unit 111 are rotated by 90° relative to the microlenses 11 in the nth row and mth column in the second lens unit 112 . The microlens 11 in the nth row and mth column of the third lens unit 113 is rotated by 90° relative to the microlens 11 in the nth row and mth column of the fourth lens unit 114 . And the microlens 11 in the nth row and mth column in the third lens unit 113 is rotated by 45° relative to the microlens 11 in the nth row and mth column in the first lens unit 111, where n≥1 and m≥1.

In this application, the optoelectronic device 20 also includes a third optoelectronic unit 23 and a fourth optoelectronic unit 24, the first lens unit 111 is arranged opposite to the first optoelectronic unit 21, and the second lens unit 112 is arranged opposite to the second optoelectronic unit 22, The third lens unit 113 is arranged opposite to the third photoelectric unit 23 , and the fourth lens unit 114 is arranged opposite to the fourth photoelectric unit 24 .

The metalens 10 decomposes the first incident light 51 into a first polarized light 61, a second polarized light 62, a third polarized light and a fourth polarized light. The polarization angle of the first polarized light 61 is 0°. , the polarization angle of the second polarized light 62 is 90°, the polarization angle of the third polarized light is 45°, and the polarization angle of the fourth polarized light is 135°.

In this application, the optoelectronic device 20 further includes a third optoelectronic unit 23 and a fourth optoelectronic unit 24. The third polarized light is incident on the third optoelectronic unit 23, and the fourth polarized light is incident on the fourth optoelectronic unit 24.

Specifically, as shown in FIGS. 2 and 5 , a plurality of microlenses 11 are used to form four lens units. The four lens units are respectively a first lens unit 111 , a second lens unit 112 , and a third lens unit arranged in an array. Lens unit 113 and fourth lens unit 114. The first lens unit 111 , the second lens unit 112 , the third lens unit 113 and the fourth lens unit 114 are respectively shown in FIG. 2 . The optoelectronic device 20 has a first optoelectronic unit 21 and a second optoelectronic unit corresponding to the four lens units respectively. 22. The third photoelectric unit 23 and The fourth photoelectric units 24 are configured to form one pixel respectively.

11 and 12, the first lens unit 111 and the second lens unit 112 are arranged in sequence in the X direction, the first lens unit 111 and the third lens unit 113 are arranged in sequence in the Y direction, and The two lens units 112 and the fourth lens unit 114 are arranged sequentially in the Y direction. Referring to Figure 3, the first lens unit 111 can focus 90° polarized light on the first photoelectric unit 21 and focus 0° polarized light on the first photoelectric unit 21. On the second photovoltaic unit 22. The second lens unit 112 can focus 0° polarized light onto the second photoelectric unit 22 and focus 90° polarized light onto the first photoelectric unit 21 . The third lens unit 113 can focus 135° polarized light onto the third photovoltaic unit 23 and focus 45° polarized light onto the fourth optoelectronic unit 24 . The fourth lens unit 114 can focus 45° polarized light onto the fourth photoelectric unit 24 and focus 135° polarized light onto the third photoelectric unit 23 .

In this application, each lens unit and a photoelectric unit completely correspond in the z direction and together form a pixel. Each group of four pixels with different designs serves as a calculation unit.

In this application, the lens unit can focus 0°, 45°, 90°, and 135° polarized light onto different corresponding photoelectric units according to the different polarization directions of the incident light. The recorded light intensity information enables calculation of the degree and direction of polarization.

Wherein, the first pixel and the second pixel are arranged sequentially in the x direction at intervals from each other. As shown in Figures 10, 11 and 12, the first lens unit 111 in the first pixel can focus the incident light with a polarization direction of 90° to the first photoelectric unit 21 in the main axis direction, and change the polarization direction The incident light of 0° is focused onto the second photoelectric unit 22 of the second pixel next to it. Correspondingly, the second lens unit 112 in the second pixel can focus the incident light with the polarization direction of 0° to the second photoelectric unit 22 in the main axis direction, and focus the incident light with the polarization direction of 90°. Focus on the first photoelectric unit 21 of another first pixel next to it.

Similarly, the third and fourth pixels used to modulate 45° and 135° polarized light are arrayed in the x direction in the same manner. That is, the third lens unit 113 in the third picture element can focus 135° polarized light onto the third photoelectric unit 23 in its main axis direction, and focus 45° polarized light onto the fourth photoelectric unit 24 on the side. The fourth lens unit 114 in the fourth pixel can focus 45° polarized light onto the main axis The 135° polarized light is focused on the fourth photoelectric unit 24 on the other side to the third photoelectric unit 23 on the side.

In this embodiment, the polarization angle difference between the pixels in the x direction is 90°, and the polarization angle difference between the pixels in the y direction is 45°. As shown in Figure 11 and Figure 12, this application focuses the polarized light of 0°, 45°, 90°, and 135° onto different corresponding photoelectric units to ensure that the light beams with different polarization directions can be fully focused after decomposition. to the optoelectronic device 20, which not only effectively improves the extinction ratio, but also greatly improves the light transmittance.

According to an embodiment of the present invention, as shown in Figures 2, 5, 13 and 14, the metalens 10 includes a first lens unit 111, a second lens unit 112, a third lens unit 113 and a fourth lens unit. 114. The first lens unit 111, the second lens unit 112, the third lens unit 113 and the fourth lens unit 114 each include a plurality of microlenses 11. As shown in FIGS. 13 and 14 , the plurality of microlenses 11 in the first lens unit 111 , the second lens unit 112 , the third lens unit 113 and the fourth lens unit 114 are respectively distributed in an array, and the first The lens unit 111 and the second lens unit 112 are arranged diagonally, and the first lens unit 111 and the third lens unit 113 are arranged in a horizontal direction.

Referring to Figures 12 and 13, the microlens 11 in the nth row and mth column in the first lens unit 111 is rotated 45° relative to the microlens 11 in the nth row and mth column in the third lens unit 113. The microlens 11 in the nth row and mth column rotates 45° relative to the axis of the microlens 11 in the nth row and mth column in the second lens unit 112, and the microlens 11 in the nth row and mth column in the fourth lens unit 114 Rotate 135° relative to the microlens 11 in the n-th row and m-th column in the first lens unit 111, where n≥1 and m≥1.

The metalens 10 decomposes the first incident light 51 into a first polarized light 61, a second polarized light 62, a third polarized light and a fourth polarized light. The polarization angle of the first polarized light 61 is 0°. , the polarization angle of the second polarized light 62 is 90°, the polarization angle of the third polarized light is 45°, and the fourth polarized light The polarization angle is 135°.

That is to say, referring to Figures 13 and 14, this application changes the arrangement of the angles between the first pixel, the second pixel, the third pixel and the fourth pixel and the x-axis by changing the design parameters of the nano-columns. , while matching the polarization angle of polarized light. Changing the length and width of the lens unit adjusts the propagation phase accumulated by the nanocolumn to change the response characteristics of the lens unit to various types of linear polarization.

As shown in Figures 13 and 14, the first lens unit 111 and the third lens unit 113 are arranged in sequence in the X direction, the first lens unit 111 and the fourth lens unit 114 are arranged in sequence in the Y direction, and the second lens unit The unit 112 and the third lens unit 113 are arranged sequentially in the Y direction. The first lens unit 111 in the first image element can focus 45° polarized light onto the first photoelectric unit 21 on its main axis, and focus 0° polarized light onto the second photoelectric unit 22 on the side. The second lens unit 112 of the second pixel can focus 0° polarized light onto the second photoelectric unit 22 on its main axis, and focus 45° polarized light onto the first photoelectric unit 21 on the side.

The third lens unit 113 of the third picture element can focus 90° polarized light onto the third photoelectric unit 23 on its main axis, and focus 135° polarized light onto the fourth photoelectric unit 24 on the side. The fourth lens unit 114 in the fourth picture element can focus 135° polarized light onto the fourth photoelectric unit 24 on its main axis, and focus 45° polarized light onto the third photoelectric unit 23 on the side. In this embodiment, the polarization angle difference between pixels is 45° regardless of whether it is along the x direction or the y direction. The more uniform distribution is more conducive to subsequent signal processing.

In some specific embodiments of the present invention, as shown in FIGS. 2 to 4 , the metalens 10 further includes a fixed layer 30 . The metalens 10 includes a plurality of microlenses 11 , and each microlens 11 can be configured as a nano-column. , multiple microlenses may be embedded in the fixing layer 30 . The fixed layer 30 can be made of polydimethylsiloxane or photoresist, and the metalens 10 can be made of a transparent dielectric material. Among them, the fixing layer 30 is spin-coated on the side of the microlens 11 away from the optoelectronic device 20, so that the fixing layer 30 can penetrate into two adjacent microlenses 11. between lenses 11.

In other words, as shown in FIGS. 2 to 4 , the metalens 10 can be provided with a fixed layer 30 . The fixed layer 30 can prevent dust without providing a cover plate, further reducing the thickness of the polarization imaging sensor 100 . , reduce costs and enhance product competitiveness. The fixed layer 30 can be made of polydimethylsiloxane or photoresist, and the metalens 10 can be made of a transparent dielectric material to further improve the light transmittance of the polarization imaging sensor 100 .

The fixed layer 30 can be spin-coated on the side of the microlens 11 away from the optoelectronic device 20. By spin-coating polydimethylsiloxane or photoresist, it can prevent dust without setting a cover plate and further reduce the polarization. The thickness and size of the imaging sensor 100 reduce costs and enhance product competitiveness. Referring to Figure 3, the meta-lens 10 is spin-coated with polydimethylsiloxane or photoresist. After baking and solidification, the polydimethylsiloxane or photoresist is penetrated into the polydimethylsiloxane or photoresist between two adjacent microlenses 11. The photoresist can also ensure that the microlens 11 will not tip over, improving the stability of the overall structure of the metalens 10 .

According to an embodiment of the present invention, the polarization imaging sensor 100 further includes a fixed layer 30. The metalens 10 includes a plurality of microlenses 11. The microlenses 11 are fixed on one side of the fixed layer 30. The microlenses 11 are located between the fixed layer 30 and the fixed layer 30. between the optoelectronic devices 20 . And/or a filling layer 40 is provided between the metalens 10 and the optoelectronic device 20 .

That is to say, as shown in FIG. 4 , the polarization imaging sensor 100 also includes a fixed layer 30 , the metalens 10 includes a plurality of microlenses 11 , the microlenses 11 are disposed on one side of the fixed layer 30 , and the microlenses 11 are disposed on the fixed layer. 30 and the optoelectronic device 20. A filling layer 40 may also be provided between the metalens 10 and the optoelectronic device 20 .

As shown in FIG. 4 , the fixed layer 30 can be made of film material such as polydimethylsiloxane or SU-8 photoresist, which can not only prevent dust, but also reduce the thickness of the polarization imaging sensor 100 . The metalens 10 is a dielectric material. Compared with the linear slit metal grating in the prior art, the dielectric material has extremely low absorption of light, which is conducive to further improving the light transmittance. The metalens 10 and the optoelectronic device 20 correspond to each other in the height direction, and a filling layer 40 is provided between the metalens 10 and the optoelectronic device 20. The filling layer 40 may be a silicon dioxide substrate, and the silicon dioxide substrate is filled in Lens unit and optoelectronic device 20 free communication area between pieces.

According to an embodiment of the present invention, the metalens 10 performs paraxial focusing on 0° polarized light and off-axis focusing on 90° polarized light.

In other words, in an embodiment of the present application, as shown in Figures 15 to 17, curve a in Figure 15 is a diagram of the change of the light intensity of the first pixel with the polarization angle of the incident light, and curve b is a diagram of the change of the light intensity of the first pixel with the polarization angle of the incident light. The light intensity of the pixel changes with the polarization angle of the incident light. In order to verify the polarization multiplexing characteristics of the meta-lens 10, taking the second pixel as an example, the second lens unit 112 of the second pixel is designed to have a central operating wavelength of 550 nm, and the nano-column is a sub-wavelength structural unit. The height H is designed to be 480nm, the period P is designed to be 300nm, and the material is titanium dioxide. In order to achieve polarization multiplexing, a total of 64 types of nanopillars (subwavelength structural units) with different sizes were selected.

It should be noted that the above structural parameters and materials are only selected to prove the functions of the embodiments, and of course cannot be used to limit the scope of the present invention. The dimensions H and P of the sub-wavelength structural unit (nano-column) can usually be designed between half wavelength and the central operating wavelength. For example, in this embodiment, they can be designed to be 250 nm to 500 nm. The material can be flexibly selected according to the working wavelength. For example, in this embodiment, amorphous silicon can be used instead of titanium dioxide. You can also choose 32, 16, 8, and 4 sub-wavelength structural units with different sizes to build the lens unit.

In this embodiment, the size of the second lens unit 112 is set to a square with a side length of 3.9 microns, and the incident light is set to a simple plane wave. Specifically, for 0° polarized light, the second lens unit 112 in the second pixel needs to achieve paraxial focusing, and the focus coordinates are set to (0, 0, 5 μm). For 90° polarized light, the second lens unit 112 in the second pixel needs to achieve off-axis focusing, and the focus coordinates are set to (3.9 μm, 0, 5 μm). The phase distribution of the lens unit required to achieve this function is directly encoded onto the structural unit at each spatial position, and linearly polarized light directly presents this phase distribution through the propagation phase effect. From the electric field distribution diagram in the xz plane obtained by simulation calculation (see Figures 16 and 17), it can be clearly observed from the figure that the second lens unit 112 achieves paraxial focusing for 0° polarized light, while for 90° polarized light Off-axis focusing is achieved.

Similarly, in another embodiment of the present application, as shown in Figures 18 and 19, the second Taking the second lens unit 112 in the pixel as an example, in order to verify its polarization multiplexing characteristics described in this embodiment, that is, to achieve paraxial focusing of 0° polarized light, the focus coordinates are set to (0, 0, 5 μm ). At the same time, off-axis focusing along the diagonal direction is achieved for 90° polarized light, and the focus coordinates are set to (3.9 μm, 3.9 μm, 5 μm). The figure shows the respective focusing results of 0° and 90° polarized light after passing through the second lens unit 112 on the target focal image plane z=5 μm. It can be observed from the simulation results that the 0° polarized light is focused at the center of the image plane, achieving the effect of paraxial focusing. At the same time, the 90° polarized light is focused at the coordinates (3.9μm, 3.9μm, 5μm), achieving off-axis focusing along the diagonal direction.

In summary, according to the polarization imaging sensor 100 according to the embodiment of the present invention, by designing the optoelectronic device 20 and the meta-lens 10 instead of the design of the polarization filter, the meta-lens 10 can vectorize the converged light beams with different polarization angles. The decomposed light beam can all be focused on the optoelectronic device 20 , thereby effectively improving the light transmittance while ensuring the extinction ratio of the polarization imaging sensor 100 . At the same time, the overall thickness of the polarization imaging sensor 100 of the present application is thinner, and the assembly is easier.

According to a second aspect of the present application, an electronic device is provided, including the polarization imaging sensor 100 in the above embodiment. Since the polarization imaging sensor 100 according to the embodiment of the present invention has the above technical effects, the electronic device according to the embodiment of the present invention should also have the corresponding technical effects. That is, the electronic device of the present application can effectively achieve Taking into account both the extinction ratio and light transmittance, it can also reduce the thickness and size to improve the user experience.

Of course, for those skilled in the art, other structures and working principles of electronic devices can be understood and implemented, and will not be described in detail in this application.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" or the like is intended to be incorporated into the description of the implementation. An example or example describes a specific feature, structure, material, or characteristic that is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, one of ordinary skill in the art will appreciate that Solution: Various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the invention. The scope of the invention is defined by the claims and their equivalents.

Claims

A polarization imaging sensor including:

Meta-lens, the meta-lens decomposes the first incident light into a first polarized light and a second polarized light, and the polarization angle of the first polarized light is different from the polarization angle of the second polarized light. ;

An optoelectronic device includes a first optoelectronic unit and a second optoelectronic unit. The first polarized light is incident on the first optoelectronic unit, and the second polarized light is incident on the second optoelectronic unit.
The polarization imaging sensor according to claim 1, wherein the second incident light is incident on the first photoelectric unit after passing through the metalens, and the polarization angle of the second incident light is consistent with the first polarization state. The polarization angles of the lights are the same, and the polarization angle of the second incident light is different from the polarization angle of the first incident light;

The first photoelectric unit receives and records the first polarized light decomposed by the first incident light after passing through the metalens and the second incident light after passing through the metalens.
The polarization imaging sensor according to claim 1, wherein the meta-lens includes a first lens unit and a second lens unit, the first lens unit is arranged opposite to the first photoelectric unit, and the second lens unit The unit is arranged opposite to the second optoelectronic unit, the first lens unit and the second lens unit each include a plurality of microlenses, and the plurality of microlenses in the second lens unit are opposite to the first lens unit. The microlens at the corresponding position deflects at a first angle, and the angle difference between the polarization angle of the first polarized light and the polarization angle of the second polarized light is equal to the first angle.
The polarization imaging sensor according to claim 1, wherein the meta-lens includes a plurality of micro-lenses, and the length, width, height or extending directions of the sides of the plurality of micro-lenses are different.
The polarization imaging sensor according to claim 1, wherein the meta-lens includes a first lens unit and a second lens unit, the first lens unit is arranged opposite to the first photoelectric unit, and the second lens unit The unit is arranged opposite to the second photoelectric unit, the first lens unit and the second lens unit each include a plurality of microlenses, and each of the microlenses in the second lens unit is the first Each of the microlenses in the lens unit is rotated by the same angle relative to its own axis.
The polarization imaging sensor of claim 1, wherein the metalens includes a A lens unit and a second lens unit, the first lens unit is opposite to the first optoelectronic unit, the second lens unit is opposite to the second optoelectronic unit, the first lens unit and the Each of the second lens units includes a plurality of microlenses. The plurality of microlenses in the first lens unit and the second lens unit are respectively distributed in an array. The nth row and mth row of the first lens unit The structures of the microlenses in the column and the microlenses in the nth row and mth column in the second lens unit are symmetrical to each other, where n≥1 and m≥1.
The polarization imaging sensor according to claim 3, wherein the first lens unit and the second lens unit are diagonally distributed, and a plurality of the first lens unit and the second lens unit are The microlenses are respectively distributed in an array, and the microlenses in the nth row and mth column in the first lens unit rotate the microlenses in the nth row and mth column in the second lens unit. An angle, where n≥1 and m≥1.
The polarization imaging sensor according to claim 1, wherein the meta-lens includes a first lens unit, a second lens unit, a third lens unit and a fourth lens unit, the first lens unit, the second lens unit The lens unit, the third lens unit and the fourth lens unit each include a plurality of microlenses;

A plurality of the microlenses in the first lens unit, the second lens unit, the third lens unit and the fourth lens unit are respectively distributed in an array, and the first lens unit and the The fourth lens unit is arranged diagonally, and the first lens unit and the second lens unit are arranged in a horizontal direction;

The microlenses in the nth row and mth column in the first lens unit are rotated 90° relative to the microlenses in the nth row and mth column in the second lens unit, and the nth microlenses in the third lens unit are The microlenses in the mth row and column are rotated 90° relative to the microlenses in the nth row and mth column in the fourth lens unit, and the microlenses in the nth row and mth column in the third lens unit are The lens rotates 45° relative to the microlenses in the nth row and mth column of the first lens unit, where n≥1 and m≥1.
The polarization imaging sensor according to claim 1, wherein the meta-lens includes a first lens unit, a second lens unit, a third lens unit and a fourth lens unit, the first lens unit, the second lens unit The lens unit, the third lens unit and the fourth lens unit each include a plurality of micro lens;

A plurality of the microlenses in the first lens unit, the second lens unit, the third lens unit and the fourth lens unit are respectively distributed in an array, and the first lens unit and the The second lens unit is arranged diagonally, and the first lens unit and the third lens unit are arranged in a horizontal direction;

The microlenses in the nth row and mth column in the first lens unit are rotated 45° relative to the microlenses in the nth row and mth column in the third lens unit, and the nth microlenses in the fourth lens unit are The microlenses in the mth row and mth column are rotated by 45° relative to the axis of the microlenses in the nth row and mth column in the second lens unit, and all the microlenses in the nth row and mth column in the fourth lens unit are The microlens rotates 135° relative to the microlens in the nth row and mth column of the first lens unit, where n≥1 and m≥1.
The polarization imaging sensor according to any one of claims 8 or 9, wherein the optoelectronic device further includes a third optoelectronic unit and a fourth optoelectronic unit, and the first lens unit is arranged opposite to the first optoelectronic unit. , the second lens unit is arranged opposite to the second photoelectric unit, the third lens unit is arranged opposite to the third photoelectric unit, and the fourth lens unit is arranged opposite to the fourth photoelectric unit;

The meta-lens decomposes the first incident light into a first polarized light, a second polarized light, a third polarized light and a fourth polarized light, and the polarization angle of the first polarized light is 0 °, the polarization angle of the second polarized light is 90°, the polarization angle of the third polarized light is 45°, and the polarization angle of the fourth polarized light is 135°;

The third polarized light is incident on the third optoelectronic unit, and the fourth polarized light is incident on the fourth optoelectronic unit.
The polarization imaging sensor according to claim 1, further comprising: a fixed layer, the meta-lens includes a plurality of microlenses, and the plurality of microlenses are embedded in the fixed layer.
The polarization imaging sensor according to claim 11, wherein the fixed layer is polydimethylsiloxane or photoresist, and the metalens is a transparent dielectric material; wherein the fixed layer is spin-coated on The side of the microlens away from the optoelectronic device enables the fixing layer to penetrate between two adjacent microlenses.
The polarization imaging sensor according to claim 1, further comprising a fixed layer, the meta-lens including a plurality of microlenses, the microlenses are fixed on one side of the fixed layer, the microlenses are located at between the fixing layer and the optoelectronic device.
The polarization imaging sensor according to claim 1, wherein a filling layer is provided between the metalens and the optoelectronic device.
The polarization imaging sensor according to claim 1, wherein the meta-lens performs paraxial focusing on 0° polarized light and off-axis focusing on 90° polarized light.
An electronic device including the polarization imaging sensor according to any one of claims 1-15.