Holographic photosensitive component and imaging equipment

Abstract

The invention provides a holographic photosensitive assembly and an imaging device, which can save cost to a certain extent and facilitate realization of low-cost mass production. The holographic photosensitive component comprises a CMOS photosensitive element which is provided with a plurality of pixel points arranged in an array; and the holographic color router is made of a holographic optical element, and the holographic color router is arranged on the photosensitive side of the CMOS photosensitive element and is used for focusing the light of each wave band on the corresponding pixel point in the CMOS photosensitive element.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photosensitive technology, and in particular, to a holographic photosensitive assembly and an imaging device. BACKGROUND

[0002] In recent years, with the popularity of imaging devices such as smart phones, single-lens reflex cameras or micro-single cameras, the market demand for CMOS image sensors (CIS) is increasing day by day. For traditional photosensitive assemblies, after the external light is imaged by the lens, it needs to be focused on the pixel points of the photosensitive element through the micro lens array (MLA); and in order to realize color imaging, a color filter array (CFA) is often arranged between the micro lens array and the photosensitive element to filter out light of a specific color and hit the corresponding pixel points on the photosensitive element to realize color photosensitive imaging. However, such a traditional photosensitive assembly needs to mass-produce micro lens arrays, resulting in high cost.

[0003] Recently, the concept of color router has gradually become popular with the development of optical meta-surface technology, which can guide different colors of light within a certain range to the corresponding pixel points, achieving nearly 100% utilization of incident light and greatly improving the photosensitive performance of CIS. As a technology with great potential for realizing color routing, the meta-surface precisely controls the wavefront and transmittance of incident light through the arrangement of sub-wavelength structures, and can realize independent control of different wavelengths through topology optimization, which is one of the ideal means to realize color routing. However, the designed meta-surface color router is often difficult to realize low-cost mass production due to the complex topology of the microstructure. SUMMARY

[0004] One advantage of the present application is to provide a holographic photosensitive assembly and an imaging device, which can save costs to some extent and facilitate low-cost mass production.

[0005] Another advantage of the present application is to provide a holographic photosensitive assembly and an imaging device, wherein in one embodiment of the present application, the holographic photosensitive assembly can change the production process of the MLA into the exposure recording production of the holographic optical element, which can save costs to some extent and improve the efficiency of low-cost mass production.

[0006] Another advantage of the present application is to provide a holographic photosensitive assembly and an imaging device, wherein in one embodiment of the present application, the holographic photosensitive assembly can save production costs while improving the light utilization rate to some extent.

[0007] Another advantage of the present application is to provide a holographic photosensitive assembly and imaging device, wherein in one embodiment of the present application, the holographic photosensitive assembly can greatly improve light utilization while achieving low-cost mass production.

[0008] Another advantage of the present application is to provide a holographic photosensitive assembly and imaging device, wherein in order to achieve the above-mentioned purpose, in the present application, a complex structure is not required. Therefore, the present application successfully and effectively provides a solution, not only providing a simple holographic photosensitive assembly and imaging device, but also increasing the practicability and reliability of the holographic photosensitive assembly and imaging device.

[0009] In order to achieve the above-mentioned at least one advantage or other advantages and purposes of the present application, the present application provides a holographic photosensitive assembly, comprising: a CMOS photosensitive element having a plurality of pixel points arranged in an array; and a holographic color router made of a holographic optical element, the holographic color router being arranged on the photosensitive side of the CMOS photosensitive element, for focusing each waveband light onto the corresponding pixel point in the CMOS photosensitive element.

[0010] In one embodiment of the present application, the plurality of pixel points of the CMOS photosensitive element includes a first pixel point for receiving first waveband light, a second pixel point for receiving second waveband light, and a third pixel point for receiving third waveband light; the holographic color router simultaneously records the wavefront phases of the first waveband light, the second waveband light, and the third waveband light.

[0011] In one embodiment of the present application, the holographic color router includes a first holographic optical element and a color filter array; the first holographic optical element records the wavefront phases of a plurality of waveband lights after passing through a microlens array, for simultaneously focusing a plurality of waveband lights onto each pixel point; the color filter array is located in the optical path between the first holographic optical element and the CMOS photosensitive element.

[0012] In one embodiment of the present application, the first holographic optical element is a single-layer holographic optical element; the single-layer holographic optical element simultaneously records the wavefront phases of a plurality of waveband lights after passing through a microlens array.

[0013] In one embodiment of the present application, the first holographic optical element is a multi-layer holographic optical element, each layer of the multi-layer holographic optical element records the wavefront phase of only one waveband light after passing through a microlens array.

[0014] In an embodiment of the present application, the first holographic optical element comprises a first HOE layer, a second HOE layer and a third HOE layer stacked with each other; the first HOE layer only records the wavefront phase of the light rays in the first waveband after passing through the microlens array; the second HOE layer only records the wavefront phase of the light rays in the second waveband after passing through the microlens array; and the third HOE layer only records the wavefront phase of the light rays in the third waveband after passing through the microlens array.

[0015] In an embodiment of the present application, the holographic color router is a second holographic optical element, which records the wavefront phase of the light rays in multiple wavebands after passing through the metasurface color router, for focusing the light rays in multiple wavebands onto multiple pixel points in the CMOS photosensitive element one by one.

[0016] In an embodiment of the present application, the second holographic optical element is a single-layer holographic optical element, which simultaneously records the wavefront phase of the light rays in multiple wavebands after passing through the metasurface color router.

[0017] In an embodiment of the present application, the second holographic optical element is a multi-layer holographic optical element, each layer of the multi-layer holographic optical element only records the wavefront phase of the light rays in one waveband after passing through the metasurface color router.

[0018] According to another aspect of the present application, an embodiment of the present application provides an imaging device, comprising: the above-mentioned holographic photosensitive assembly; and an optical lens arranged in the light receiving path of the holographic photosensitive assembly. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of a holographic photosensitive assembly according to an embodiment of the present application;

[0020] Figure 2 A first example of a holographic photosensitive assembly according to the above-mentioned embodiment of the present application is shown;

[0021] Figure 3 An exposure recording schematic diagram of a first holographic optical element in a holographic photosensitive assembly according to the first example of the present application is shown;

[0022] Figure 4 A second example of a holographic photosensitive assembly according to the above-mentioned embodiment of the present application is shown;

[0023] Figure 5 A third example of a holographic photosensitive assembly according to the above-mentioned embodiment of the present application is shown;

[0024] Figure 6An exposure recording schematic diagram of a second holographic optical element in a holographic photosensitive assembly according to the third example of the present application is shown.

[0025] Figure 7 A fourth example of a holographic photosensitive assembly according to the above embodiments of the present application is shown.

[0026] Main element symbol explanation:

[0027] 1, holographic photosensitive assembly; 10, CMOS photosensitive element; 100, pixel point; 101, first pixel point; 102, second pixel point; 103, third pixel point; 20, holographic color router; 21, first holographic optical element; 22, color filter array; 23, second holographic optical element; 201, first HOE layer; 202, second HOE layer; 203, third HOE layer; 2, microlens array; 3, metasurface color router.

[0028] The above main element symbol explanation further details the present application in combination with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0029] The following description is provided to enable those skilled in the art to carry out the present application. The preferred embodiments in the following description are only examples and other obvious modifications can be made by those skilled in the art. The basic principles defined in the following description of the present application can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0030] In the description of the present application, it should be understood that "first", "second", etc. are only for the purpose of description and should not be understood as indicating or implying relative importance. In the description of the present application, it should be noted that unless otherwise specified and limited, "connected", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through a medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0032] Considering that the existing designed metasurface color router is difficult to realize low-cost mass production due to the complex topology of the microstructure. Based on this, the present application creatively proposes a holographic photosensitive assembly and an imaging device, which can save costs to a certain extent and facilitate low-cost mass production.

[0033] Specifically, referring to the drawings of the specification of the present application Figures 1 to 7 According to one embodiment of the present application, an imaging device can include a holographic photosensitive assembly 1 and an optical lens (not shown in the figure), which is arranged in the receiving light path of the holographic photosensitive assembly 1, so that the object light is first modulated into an image by the optical lens, and then received by the holographic photosensitive assembly 1 to collect image information. It can be understood that the imaging device mentioned in the present application can be implemented as an electronic device with imaging function such as a smart phone, a single-lens reflex camera or a micro-single camera, but is not limited thereto.

[0034] More specifically, as Figure 1 The holographic photosensitive assembly 1 can include a CMOS photosensitive element 10 and a holographic color router 20 made of a holographic optical element. The CMOS photosensitive element 10 has a plurality of pixel points 100 arranged in an array. The holographic color router 20 is arranged on the photosensitive side of the CMOS photosensitive element 10, and the holographic color router 20 records the wavefront phase of a plurality of waveband lights corresponding to a plurality of pixel points 100, for focusing each waveband light on the corresponding pixel point 100 in the CMOS photosensitive element 10, to realize color photosensitive imaging.

[0035] It is worth noting that the raw material of the holographic optical element (HOE) is generally a photosensitive film, which can record the wavefront phase of the object light during exposure, and reproduce the transmitted wavefront when the reference light is irradiated again, so it is very suitable as a device for recording specific phase. The holographic color router 20 of the present application uses a holographic optical element to replace the microlens array and / or color filter array in the traditional photosensitive component to achieve the effect of color photosensitive imaging; at the same time, since the raw material of the holographic optical element has low production cost, the cost of exposure device is also relatively low, therefore, the holographic color router 20 of the present application uses a holographic optical element as a color sensing auxiliary device of the CMOS photosensitive element 10, which helps to reduce the production cost and can save cost to a certain extent, facilitating low-cost mass production.

[0036] Exemplarily, as shown in Figure 1 , the plurality of pixel points 100 of the CMOS photosensitive element 10 can include a first pixel point 101 for receiving first waveband light, a second pixel point 102 for receiving second waveband light, and a third pixel point 103 for receiving third waveband light. In this way, the holographic color router 20 of the present application simultaneously records the wavefront phases of the first waveband light, the second waveband light and the third waveband light, and can sequentially focus the first waveband light, the second waveband light and the third waveband light to the first pixel point 101, the second pixel point 102 and the third pixel point 103 in the CMOS photosensitive element 10, thereby realizing color photosensitive imaging. It can be understood that the first waveband light, the second waveband light and the third waveband light mentioned in the present application can be but not limited to red light, green light and blue light.

[0037] Specifically, in the first example of the present application, as shown in Figure 2 and Figure 3 , the holographic color router 20 can include a first holographic optical element 21 and a color filter array 22. The first holographic optical element 21 records the wavefront phase of the plurality of waveband lights after passing through the microlens array 2, and is used to focus the plurality of waveband lights to each pixel point at the same time. The color filter array 22 is located in the optical path between the first holographic optical element 21 and the CMOS photosensitive element 10, and is used to selectively transmit each waveband light to focus on the corresponding pixel point, and filter out other waveband lights focused on the corresponding pixel point.

[0038] More specifically, as shown in Figure 2 and Figure 3As shown, the first holographic optical element 21 records the wavefront phase of the first waveband light, the second waveband light and the third waveband light after passing through the microlens array 2, for focusing the first waveband light, the second waveband light and the third waveband light to each pixel point at the same time. The color filter array 22 is used for selectively transmitting the first waveband light to focus on the first pixel point 101, and filtering out other waveband lights (including the second waveband light and the third waveband light) focused on the first pixel point 101, to ensure that the first pixel point 101 only receives the first waveband light; the color filter array 22 is also used for selectively transmitting the second waveband light to focus on the second pixel point 102, and filtering out other waveband lights (including the first waveband light and the third waveband light) focused on the second pixel point 102, to ensure that the second pixel point 102 only receives the second waveband light; at the same time, the color filter array 22 is also used for selectively transmitting the third waveband light to focus on the third pixel point 103, and filtering out other waveband lights (including the first waveband light and the second waveband light) focused on the third pixel point 103, to ensure that the third pixel point 103 only receives the third waveband light.

[0039] It is worth noting that, in the above first example of the present application, as shown, Figure 2 The first holographic optical element 21 can be implemented as a single-layer holographic optical element; the single-layer holographic optical element simultaneously records the wavefront phase of multiple waveband lights after passing through the microlens array. In other words, as shown, Figure 3 The first example of the present application only needs to produce one microlens array 2 to simultaneously provide the wavefront phase of multiple object lights (including the first waveband light, the second waveband light and the third waveband light) in the mass production process, and mass-produce single-layer holographic optical elements to record the wavefront phase, so that each single-layer holographic optical element can realize the same function as the microlens array 2 when actually used, thereby greatly saving the cost of mass-producing microlens arrays.

[0040] In addition, although the single-layer holographic optical element can simultaneously record the wavefront phase of multiple waveband lights, it can realize the wavelength multiplexing function, that is, different waveband reconstruction lights can diffract different wavefronts; however, when using the wavelength multiplexing function, the diffraction efficiency of the single-layer holographic optical element for each waveband light will be reduced, that is, when the diffraction efficiency is relatively balanced, the diffraction efficiency of each waveband light is basically equal to the reciprocal of the total number of wavebands. For example, taking the first waveband light, the second waveband light and the third waveband light as an example, when using the wavelength multiplexing function of the single-layer holographic optical element, if it is desired to make the efficiencies of the three color lights consistent, the highest diffraction efficiency of the three color lights is basically 1 / 3, resulting in that the light utilization efficiency of the holographic photosensitive assembly 1 in the first example of the present application is basically the same as that of the traditional photosensitive assembly.

[0041] To improve the utilization rate of light energy, additional Figure 4 A second example of the holographic photosensitive component 1 of the above embodiments of this application is shown. Specifically, the first holographic optical element 21 is implemented as a multilayer holographic optical element. Each layer of the multilayer holographic optical element records only the wavefront phase of one wavelength light after passing through the microlens array, such that the diffraction efficiency of each layer of the holographic optical element for the corresponding wavelength light is essentially equal to 1. In other words, in the mass production process of the holographic color router 20 of the second example of this application, only one microlens array needs to be produced to provide the wavefront phase of each object light (such as the first wavelength light, the second wavelength light, or the third wavelength light), and single-layer holographic optical elements are used in batches to record only the corresponding wavefront phase, while being insensitive to other wavelength light; finally, the single-layer holographic optical elements recording different wavefront phases are stacked together to form a multilayer holographic optical element that realizes the function of the microlens array; at the same time, the light utilization efficiency of the holographic photosensitive component 1 can be greatly improved.

[0042] For example, in the second example of this application, such as Figure 4 As shown, the first holographic optical element 21 includes a first HOE layer 201, a second HOE layer 202, and a third HOE layer 203 stacked on top of each other. The first HOE layer 201 records only the wavefront phase of the first band light after passing through the microlens array, and is used to focus the first band light onto each pixel. The second HOE layer 202 records only the wavefront phase of the second band light after passing through the microlens array, and is used to focus the second band light onto each pixel. The third HOE layer 203 records only the wavefront phase of the third band light after passing through the microlens array, and is used to focus the third band light onto each pixel. It is understandable that, since each HOE layer in the second example of the holographic photosensitive component 1 of this application only records the wavefront phase of one wavelength light and is not sensitive to other wavelength light, the diffraction efficiency of the first holographic optical element 21 for each wavelength light is basically equal to 1. Therefore, compared with the first example of the holographic photosensitive component 1 of this application, the light utilization efficiency of the second example of the holographic photosensitive component 1 of this application is improved by three times.

[0043] It is worth noting that, although in the above first example and second example of the present application, the holographic photosensitive assembly 1 uses holographic optical elements to replace the microlens array in the traditional photosensitive assembly, both the batch production of the microlens array can be saved, and the production cost of the raw material of the holographic optical element and the cost of the exposure device are low, so as to save the cost to a certain extent; However, the holographic photosensitive assembly 1 in the above first example and second example of the present application still uses the color filter array in the traditional photosensitive assembly, which only allows the waveband light corresponding to each pixel point to pass through, and filters out other waveband light, resulting in a large discount in light utilization efficiency.

[0044] In order to solve this problem, in other examples of the present application: Figures 5 to 7 The holographic color router 20 can be implemented as a second holographic optical element 23, which records the wavefront phase of multiple waveband lights after passing through the metasurface color router 3, for focusing the multiple waveband lights one by one on the multiple pixel points 100 in the CMOS photosensitive element 10. In other words, the holographic photosensitive assembly 1 of the present application can use the second holographic optical element 23 to replace the microlens array and the color filter array in the traditional photosensitive assembly, which not only realizes the color routing effect, but also improves the light utilization efficiency. It can be understood that the metasurface color router 3 mentioned in the present application can be designed by simulation, or can be designed by referring to existing literature, which will not be described here.

[0045] Exemplarily, in the third example of the present application, as shown in Figure 5 And Figure 6 The second holographic optical element 23 is implemented as a single-layer holographic optical element. The single-layer holographic optical element records the wavefront phase of the first waveband light, the second waveband light and the third waveband light after passing through the metasurface color router 3. In other words, as shown in Figure 6As shown, in the mass production process of the holographic color router 20 of the third example of this application, only one metasurface color router 3 needs to be produced to simultaneously provide the wavefront phases of multiple object lights (including first-band light, second-band light, and third-band light). By using single-layer holographic optical elements to record these wavefront phases in batches, each single-layer holographic optical element can achieve the same function as the metasurface color router in actual photography, thereby significantly reducing the cost of mass-producing metasurface color routers. It is understandable that although the luminous efficiency of single-layer holographic optical elements is not as high as that of metasurface color routers when using them to replace metasurface color routers for color routing, single-layer holographic optical elements are lower in cost than the structurally complex metasurface color routers, and background stray light can be resolved by algorithms. This results in a significant cost advantage for single-layer holographic optical elements, enabling large-scale, low-cost production.

[0046] Furthermore, although the diffraction efficiency of a single-layer holographic optical element decreases for each wavelength band when using wavelength multiplexing, meaning that when the diffraction efficiency is relatively balanced, the diffraction efficiency of each wavelength band is basically equal to the reciprocal of the total number of wavelength bands, the holographic photosensitive component 1 in the third example of this application eliminates the color filter array compared to the first example above, which can significantly improve light utilization. For example, taking the first, second, and third wavelength bands as examples, when using the wavelength multiplexing function of this single-layer holographic optical element, if we want the efficiency of the three colors of light to be close to the same, the highest diffraction efficiency of these three colors of light is basically 1 / 3. Therefore, the light utilization efficiency of the three colors of light in the holographic photosensitive component 1 in the third example of this application reaches 1 / 3, which is much higher than the light utilization efficiency of these three colors of light in traditional photosensitive components.

[0047] To further improve light utilization efficiency, in the fourth example of this application, such as Figure 7 As shown, the second holographic optical element 23 is implemented as a multilayer holographic optical element stacked on top of each other. Each layer of holographic optical element records only the wavefront phase of one wavelength light after passing through the metasurface color router, so that the diffraction efficiency of each layer of holographic optical element for the corresponding wavelength light is basically equal to 1. In other words, in the mass production process of the holographic color router 20 of the fourth example of this application, only one metasurface color router needs to be produced to provide the wavefront phase of each object light (such as the first wavelength light, the second wavelength light, or the third wavelength light), and single-layer holographic optical elements are used in batches to record only the corresponding wavefront phase, while being insensitive to other wavelength light; finally, the single-layer holographic optical elements recording different wavefront phases are stacked together to form a multilayer holographic optical element that realizes the function of the metasurface color router; at the same time, the light utilization efficiency of the holographic photosensitive component 1 can be greatly improved.

[0048] For example, in the fourth example of the present application, as shown in Figure 7 The first HOE layer 201 only records the wavefront phase of the first band of light after passing through the hyper-surface color router, for focusing the first band of light to the first pixel point 101. The second HOE layer 202 only records the wavefront phase of the second band of light after passing through the hyper-surface color router, for focusing the second band of light to the second pixel point 102. The third HOE layer 203 only records the wavefront phase of the third band of light after passing through the hyper-surface color router, for focusing the third band of light to the third pixel point 103. It can be understood that, since each HOE layer in the holographic photosensitive assembly 1 of the third example of the present application only records the wavefront phase of one band of light and is not sensitive to other bands of light, the diffraction efficiency of the second holographic optical element 23 for each band of light is basically equal to 1, so compared with the holographic photosensitive assembly 1 of the third example of the present application, the light utilization efficiency of the holographic photosensitive assembly 1 of the fourth example of the present application is improved by three times, so that the light utilization efficiency of the three color lights is close to 1, which can completely solve the problem of low light efficiency of single-layer holographic optical element.

[0049] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0050] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application.

Claims

1. A holographic photosensitive assembly, characterized by The application relates to a holographic color router and a holographic photosensitive assembly. The CMOS photosensitive element comprises a plurality of pixel points for receiving first, second and third waveband lights; and the holographic color router simultaneously records the wavefront phases of the first, second and third waveband lights. The holographic color router comprises a first holographic optical element and a color filter array; the first holographic optical element records the wavefront phases of the plurality of waveband lights after the waveband lights pass through a microlens array, and is used for simultaneously focusing the plurality of waveband lights on each pixel point; and the color filter array is located in the light path between the first holographic optical element and the CMOS photosensitive element. The first holographic optical element is a single-layer holographic optical element; and the single-layer holographic optical element simultaneously records the wavefront phases of the plurality of waveband lights after the waveband lights pass through the microlens array.

2. The holographic light sensor assembly of claim 1, wherein, The first holographic optical element is a multi-layer holographic optical element; and each layer of the holographic optical element in the multi-layer holographic optical element only records the wavefront phase of one waveband light after the waveband light passes through the microlens array.

3. The holographic light sensor assembly of claim 1 or 2, wherein, The first holographic optical element comprises a first HOE layer, a second HOE layer and a third HOE layer which are stacked with each other; the first HOE layer only records the wavefront phase of the first waveband light after the waveband light passes through the microlens array; the second HOE layer only records the wavefront phase of the second waveband light after the waveband light passes through the microlens array; and the third HOE layer only records the wavefront phase of the third waveband light after the waveband light passes through the microlens array.

4. The holographic light sensor assembly of claim 3, wherein, The holographic color router is a second holographic optical element; the second holographic optical element records the wavefront phases of the plurality of waveband lights after the waveband lights pass through a super surface color router, and is used for focusing the plurality of waveband lights on the plurality of pixel points in the CMOS photosensitive element one by one.

5. The holographic light sensor assembly of claim 3, wherein, The second holographic optical element is a single-layer holographic optical element; and the single-layer holographic optical element simultaneously records the wavefront phases of the plurality of waveband lights after the waveband lights pass through the super surface color router.

6. The holographic light sensor assembly of claim 5, wherein, The second holographic optical element is a multi-layer holographic optical element; and each layer of the holographic optical element in the multi-layer holographic optical element only records the wavefront phase of one waveband light after the waveband light passes through the super surface color router.

7. The holographic light sensor assembly of claim 1 or 2, wherein, The application relates to a holographic color router and a holographic photosensitive assembly.

8. The holographic light sensor assembly of claim 7, wherein, The application relates to a holographic color router and a holographic photosensitive assembly.

9. The holographic light sensor assembly of claim 7, wherein, An optical lens is arranged in a light receiving path of the holographic photosensitive assembly.

10. An imaging device, characterized by, ​ ​ ​ ​

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