Light collecting element and photoelectric detector

Abstract

The invention provides a light collecting element and a photoelectric detector, the light collecting element comprises a body, the body comprises a first plane and a second plane which are oppositely arranged, a plurality of aspheric microstructures are formed on the body in a protruding mode from the first plane to the direction away from the second plane, and the aspheric microstructures are arranged on the body. The aspheric microstructure comprises a light incident surface facing the outer side, a reflecting surface facing the inner side, and a light emergent surface positioned on the first plane; and the aspheric microstructure is configured to totally reflect incident light entering from the light incident surface and then emit the incident light from the second plane. According to the light collecting element, large-angle incident light can be converted into small-angle emergent light, and therefore the light collecting efficiency of the light collecting element is improved.

Description

Technical Field

[0001] This invention relates to the field of optical detection technology, and more particularly to a light-collecting element and a photodetector. Background Technology

[0002] Currently, light detection has immense applications in both production and daily life. Photodetectors are used for judging light intensity of products, detecting light leakage, wavelength analysis, and many other purposes. In the research and development of photodetectors, the ability to collect light is one of the key factors in improving equipment performance. An ideal photodetector should possess high sensitivity to light to achieve an excellent signal-to-noise ratio. Furthermore, the performance of a photodetector depends not only on its accurate detection capability for incident light at small angles but also on its accurate response to incident light at large angles.

[0003] Most photodetectors on the market currently use planar light-collecting elements, which cannot effectively collect light from different angles, especially for large-angle incident light. As the incident angle increases, the proportion of reflected light also increases, resulting in less light incident on the photodetector. This leads to reduced photoelectric collection efficiency and decreased or inaccurate detection accuracy of the photodetector.

[0004] In view of this, it is indeed necessary to provide a light-collecting element and a photodetector to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a light-collecting element with high light-collecting efficiency.

[0006] To achieve the above objectives, the present invention provides a light-collecting element for use in a photodetector, comprising: a body, the body including a first plane and a second plane disposed opposite to each other, wherein a plurality of aspherical microstructures are formed on the body by protruding from the first plane in a direction away from the second plane, the aspherical microstructures including an incident surface facing outward and a reflecting surface facing inward, and an emitting surface located on the first plane; the aspherical microstructures are configured to perform total internal reflection on incident light entering through the incident surface and then emit it from the second plane.

[0007] Optionally, the multiple aspherical microstructures may be microstructures of the same size, or the multiple aspherical microstructures may be microstructures that are enlarged or reduced in proportion.

[0008] Optionally, the surface shape formula of the aspherical microstructure located on the first plane is:

[0009]

[0010] in, c=1 / (0.002*β); k=-0.9; α1=100 / β2 β is the scaling factor between the different aspherical microstructures and the aspherical microstructure used as a reference.

[0011] Optionally, the value of β can be in the range of [-15, 15].

[0012] Optionally, the aspherical microstructure is defined to have an opening length D on the light-emitting surface of the first plane, and the aspherical microstructure has a height H in the height direction perpendicular to the first plane, wherein the ratio of the height H to the opening length D is greater than 1.

[0013] Optionally, the opening length D of each of the aspherical microstructures on the first plane is less than 20 μm.

[0014] Optionally, a plurality of the aspherical microstructures are arranged in an array on the first plane, wherein the aspherical microstructures are configured in at least two columns, and the aspherical microstructures in adjacent columns are staggered.

[0015] Optionally, the aspherical microstructure is an aspherical optical lens.

[0016] Optionally, the aspherical microstructure is fabricated using a UV process.

[0017] Another object of the present invention is to provide a photodetector having the above-mentioned light-collecting element, which has high detection accuracy.

[0018] To achieve the above objectives, the present invention provides a photodetector, including a photodetector and the aforementioned light-collecting element, wherein the photodetector is configured to receive light emitted from the light-collecting element.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] The light-collecting element of this invention increases the light contact area by providing multiple aspherical microstructures protruding from the first plane of the main body. This allows incident light to enter the light-collecting element through the aspherical microstructures. Furthermore, the aspherical surface of the microstructures transforms large-angle light incident on the first plane into relatively small-angle light entering the microstructure. The incident light entering the aspherical microstructure from the incident surface undergoes lossless total internal reflection on the reflecting surface opposite the incident surface, deflecting it into small-angle light that exits from the light-emitting surface into the main body of the light-collecting element. Within the main body, the light is refracted and exits at an even smaller angle on the second plane, reducing the incident angle at which it enters the photodetector. This facilitates detection by the photodetector, significantly improving the light-collecting efficiency of the light-collecting element and fundamentally enhancing the detection accuracy of the photodetector for large-angle light. This allows the photodetector to detect light at any angle, improving its detection accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a light-collecting element according to an embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A schematic diagram of the spherical microstructure in Central Africa;

[0023] Figure 3 yes Figure 1 The optical path diagram of the light-collecting element is shown below;

[0024] Figure 4 This is the optical path diagram of a photodetector in existing technology;

[0025] Figure 5 yes Figure 4 The light collection efficiency diagram of the light-collecting element in the photodetector shown;

[0026] Figure 6 This is an optical path diagram of a photodetector conforming to an embodiment of the present invention;

[0027] Figure 7 yes Figure 6 The diagram shows the light collection efficiency of the light-collecting element in the photodetector.

[0028] Explanation of reference numerals in the attached figures:

[0029] Photodetector 100;

[0030] The light-collecting element 1, the body 11, the first plane 111, the second plane 112, the aspherical microstructure 12, the light-incident surface 121, and the reflecting surface 122;

[0031] Photoelectric receiver 2. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0034] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Please see Figures 1 to 7 As shown, an embodiment of the present invention provides a light-collecting element 1, which is applied to a photodetector 100 to collect light and transmit the light to a photodetector 2.

[0036] Please see Figures 1 to 3 As shown, the light-collecting element 1 includes a body 11 and a plurality of aspherical microstructures 12 disposed on the body 11. The aspherical microstructures 12 are three-dimensional structures.

[0037] In this embodiment, the body 11 and the aspherical microstructure 12 are integrally formed. In other embodiments, the body 11 and the aspherical microstructure 12 may also be formed by combination.

[0038] The body 11 includes a first plane 111 and a second plane 112 disposed opposite to each other. The first plane 111 is disposed towards the light source, and the second plane 112 is disposed towards the photodetector 2. That is, in the body 11, light is transmitted from the first plane 111 to the second plane 112, and then emitted from the second plane 112 to the photodetector 2.

[0039] On the body 11, a plurality of aspherical microstructures 12 are formed by protruding from the first plane 111 in a direction away from the second plane 112. That is, the aspherical microstructures 12 are disposed on the first plane 111 and protrude from the first plane 111.

[0040] Please see Figure 2 and Figure 3As shown, the aspherical microstructure 12 includes an outward-facing light-incident surface 121 and an inward-facing reflective surface 122, as well as a light-emitting surface located on the first plane 111. Both the light-incident surface 121 and the reflective surface 122 are aspherical surfaces protruding from the first plane 111. However, the light-incident surface 121 is located on the outer side and is configured to receive light, while the reflective surface 122 is located on the inner side and is configured to reflect light. The light-emitting surface is a plane disposed on the first plane 111.

[0041] By setting multiple aspherical microstructures 12 protruding from the first plane 111 on the body 11, incident light can enter the light collecting element 1 through the protruding aspherical microstructures 12, thereby increasing the light contact area of ​​the light collecting element 1.

[0042] An incident ray is defined as having an incident angle of 55° on the first plane 111, and an incident angle of 55° on the incident surface 121 of the aspherical microstructure 12, which is a curved surface convex to the first plane 111. This results in an angle less than 55° between the incident ray and the normal to the incident surface 121. For example, the incident angle of the incident ray on the incident surface 121 of the aspherical microstructure 12 can be approximately 42-48°. In other words, the aspherical incident surface 121 can transform a large-angle first incident ray into a relatively small-angle second incident ray; this transformation process is defined as the first transformation.

[0043] After the first transformation, the incident light enters the interior of the aspherical microstructure 12 from the light-incident surface 121 at a relatively small second incident angle. It then undergoes lossless total internal reflection at the reflecting surface 122 on the opposite side of the light-incident surface 121, forming a totally internalized ray. This totally internalized ray enters the body 11 from the light-exiting surface and then exits from the second plane 112, thus reducing the incident angle before entering the photodetector 2. In other words, after being reflected by the reflecting surface 122 of the aspherical microstructure 12, the incident light at the second incident angle is transformed into a totally internalized ray at a smaller third incident angle. This ray enters the body 11 from the light-exiting surface and exits from the second plane 112, where it is received by the photodetector 2. This reduces the incident angle of the light entering the photodetector 2, thereby significantly improving the light-collecting efficiency of the light-collecting element 1.

[0044] Furthermore, the surface shape formula for the aspherical microstructure 12 is:

[0045]

[0046] in, c=1 / (0.002*β); k=-0.9; α1=100 / β 2 β is the scaling factor between the different aspherical microstructures 12 and the aspherical microstructure 12 used as a reference.

[0047] Furthermore, the value range of β is [-15, 15].

[0048] The aspherical microstructure 12 is defined with an opening length D on the light-emitting surface of the first plane 111. In the height direction perpendicular to the first plane 111, the aspherical microstructure 12 has a height H, and the ratio of height H to opening length D is greater than 1. This configuration ensures that the aspherical microstructure 12 can effectively collect and guide light, increasing the light contact area and improving light collection efficiency. Furthermore, it reduces light reflection loss at the reflecting surface 122, achieving lossless total internal reflection because light more easily enters the light-collecting element 1 along the light-incident surface 121 of the aspherical microstructure 12.

[0049] Optionally, the opening length D of each aspherical microstructure 12 on the first plane 111 is less than 20 μm. This configuration reduces the size of the aspherical microstructure 12, allowing multiple aspherical microstructures 12 to be disposed on the first plane 111, thereby improving light collection efficiency.

[0050] Furthermore, the aspherical microstructure 12 is an aspherical optical lens.

[0051] Furthermore, the aspherical microstructure 12 is processed by UV transfer printing.

[0052] In this embodiment, a plurality of aspherical microstructures 12 are arranged in an array on the first plane 111, with at least two columns of aspherical microstructures 12, and adjacent columns of aspherical microstructures 12 are staggered. This arrangement allows the aspherical microstructures 12 to more effectively cover the first plane 111, thereby increasing the light-collecting area of ​​the light-collecting element 1. Furthermore, the staggered arrangement helps avoid light shading between adjacent aspherical microstructures 12, achieving a more uniform light distribution. The array-arranged microstructures maximize the use of the space in the first plane 111, improving space utilization. Of course, in other embodiments, the plurality of aspherical microstructures 12 can also be arranged in other ways, such as a hexagonal array or other arrangements.

[0053] In this embodiment, the multiple aspherical microstructures 12 have the same shape. The incident surface 121 of the aspherical microstructure 12 has a parabolic or approximately parabolic curve. This configuration allows for precise focusing of incident light rays, enhancing light collection capabilities. Furthermore, it reduces unnecessary light scattering, lowers background noise, and improves the signal-to-noise ratio.

[0054] In other embodiments, the shapes of the plurality of aspherical microstructures 12 may also be different. For example, they may have different aspherical surfaces, or different heights H, or different opening lengths D.

[0055] In this embodiment, the plurality of aspherical microstructures 12 are microstructures of the same size. In other embodiments, the plurality of aspherical microstructures 12 may also be microstructures that are proportionally enlarged or reduced in size.

[0056] Please see Figures 4 to 7 As shown, an embodiment of the present invention further provides a photodetector 100, which includes the aforementioned light-collecting element 1 and photodetector 2. The photodetector 2 is configured to receive light emitted from the light-collecting element 1. Since the light-collecting unit of the present invention can not only collect incident light at small angles, but also effectively collect incident light at medium and large angles, the amount of light received by the photodetector 2 is increased, thereby improving the photometric accuracy.

[0057] Combination Figures 3 to 7 The following description explains the optical path diagram of light passing through the light-collecting element 1 to the photodetector 2, and by comparing the optical path diagram of a conventional photodetector 100' in the prior art with the optical path diagram of the photodetector 100 of the present invention, the process of improving the light-collecting efficiency of the light-collecting element 1 of the present invention is explained in detail.

[0058] Please see Figure 4 and Figure 5 As shown, in the prior art, the incident surface of the ordinary light-collecting element 1' is the first plane. When incident light enters the ordinary light-collecting element 1', most of the incident light is reflected on the first plane 111. Furthermore, as the angle of the incident light increases, the proportion of reflected light increases, thus preventing most of the incident light from entering the ordinary light-collecting element 1' and reducing its collection efficiency. Additionally, the ordinary photodetector 2' cannot receive light from the ordinary laser element, reducing the testing accuracy of the photodetector and making it impossible to effectively measure large-angle light.

[0059] In the prior art, the incident surface of a conventional light-collecting element 1 is a first plane 111. The angle of incidence of an incident ray on the first plane 111 is defined as the first angle of incidence. That is, in the prior art, the angle at which the incident ray enters the body 11 of the conventional light-collecting element 1 is the first angle of incidence.

[0060] When the incident light enters the ordinary light-collecting element 1 at the first incident angle, most of the incident light is reflected on the first plane 111. Furthermore, as the proportion of reflected light increases with the angle of the incident light, most of the incident light cannot enter the light-collecting element 1, which reduces the collection efficiency of the light-collecting element 1, reduces the testing accuracy of the photoelectric tester, and makes it impossible to effectively measure large-angle light.

[0061] Please see Figure 3 , Figure 6 and Figure 7 The diagram shown is an optical path diagram of the photodetector 100 of the present invention. In the present invention, the incident surface 121 is the outer peripheral surface of the aspherical microstructure 12.

[0062] When the incident angle of the incident light is less than 40°, at least part of the incident light enters the aspherical microstructure 12 from the incident surface 121, undergoes lossless total internal reflection through the reflecting surface 122 of the aspherical microstructure 12, and then exits from the emitting surface to the body 11. It then exits through the second plane 112 of the body 11, thereby reducing the incident angle entering the photodetector 2. That is, small-angle incident light can be directly refracted and exit from the emitting surface into the body 11. In other words, the incident light as the body 11 can be entirely refracted light.

[0063] When the incident angle of the incident light is greater than or equal to 40° and less than or equal to 90°, the incident light still enters the aspherical microstructure 12 from the light-incident surface 121 and undergoes lossless total internal reflection on the reflecting surface 122 on the opposite side of the light-incident surface 121, forming a total internally reflected ray. The total internally reflected ray enters the body 11 from the light-exiting surface at an incident angle of less than 40° and exits from the second plane 112 of the body 11, where it is received by the photodetector 2, thereby reducing the incident angle entering the photodetector 2. That is, inside the aspherical microstructure 12, through reflection by the reflecting surface 122, the incident light at the second incident angle is transformed into a total internally reflected ray at a smaller third incident angle, entering the body 11 and exiting from the second plane 112 at a smaller angle, thereby reducing the incident angle entering the photodetector 2 and facilitating the photodetector 2 to receive the light.

[0064] Because the present invention incorporates multiple aspherical microstructures 12 protruding from the first plane 111, light rays with a large angle (first incident angle) are transformed into incident light rays with a relatively small angle (second incident angle) at the light-incident surface 121. After total internal reflection at the reflective surface 122 of the aspherical microstructure 12, the light rays exit from the light-emitting surface into the body 11 of the light-collecting element 1 at an even smaller angle (third incident angle). In other words, the large-angle incident light rays undergo two transformations to enter the incident surface of the body 11 of the light-collecting element 1 at a smaller angle. This configuration significantly improves the light-collecting efficiency of the light-collecting element 1.

[0065] The light entering the body 11 is emitted at a smaller angle from its second plane 112, thereby reducing the incident angle of the photodetector 2, making it easier for the photodetector 2 to receive the light, and thus improving the light collection efficiency and detection accuracy of the photodetector.

[0066] Please see Figure 5 and Figure 7 As shown, taking an initial incident angle of 80° as an example, in Figure 5 The light collection efficiency of the ordinary light-collecting element 1 shown is less than 40%, while... Figure 7 The light collection efficiency of the light-collecting element 1 shown can be increased to 81%, which is more than twice the original efficiency.

[0067] In summary, the light-collecting element 1 of the present invention increases the light contact area of ​​the light-collecting element 1 by providing a plurality of aspherical microstructures 12 protruding from the first plane 111 of the body 11, so that incident light enters the light-collecting element 1 through the aspherical microstructures 12. Furthermore, through the aspherical surface of the aspherical microstructures 12, light rays that should have been incident on the first plane 111 at a large angle can be transformed into incident light rays at a relatively small angle before entering the aspherical microstructures 12. By setting the aspherical surface as an outward-facing incident surface 121 and an inward-facing reflecting surface 122, large-angle incident light rays entering the aspherical microstructure 12 from the incident surface 121 can undergo lossless total internal reflection on the reflecting surface 122 on the opposite side of the incident surface 121. This causes the large-angle incident light rays to be deflected on the reflecting surface 122, turning into small-angle light rays that exit from the light-emitting surface into the body 11 of the light-collecting element 1. After refraction within the body 11, the light rays exit at an even smaller angle, facilitating reception and detection by the photodetector 2. This greatly improves the light-collecting efficiency of the light-collecting element 1, fundamentally enhancing the detection accuracy of the photodetector 100 for large-angle light rays. This allows the photodetector 100 to receive light rays at any angle, further improving the detection accuracy of the photodetector 100.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A light-collecting element used in a photodetector, characterized in that, include: The body (11) includes a first plane (111) and a second plane (112) disposed opposite to each other. On the body (11), a plurality of aspherical microstructures (12) are formed by protruding from the first plane (111) in a direction away from the second plane (112). The aspherical microstructures (12) include an incident surface (121) facing outward and a reflecting surface (122) facing inward, as well as an exiting surface located on the first plane (111). The aspherical microstructures (12) are configured to perform total internal reflection on the incident light entering through the incident surface (121) and then exit from the second plane (112).

2. The light-collecting element according to claim 1, characterized in that, The multiple aspherical microstructures (12) are microstructures of the same size, or the multiple aspherical microstructures (12) are microstructures that are enlarged or reduced in proportion.

3. The light-collecting element according to claim 2, characterized in that, The surface shape formula of the aspherical microstructure (12) located on the first plane (111) is: in, 1 / (0.002*B); k=-0.9; a1100 / B2; β is the scaling factor between different aspherical microstructures (12) and the aspherical microstructure (12) used as a reference.

4. The light-collecting element according to claim 3, characterized in that, The value range of β is [-15, 15].

5. The light-collecting element according to claim 1, characterized in that, The aspherical microstructure (12) is defined to have an opening length D on the light-emitting surface of the first plane (111), and the aspherical microstructure (12) has a height H in the height direction perpendicular to the first plane (111), wherein the ratio of the height H to the opening length D is greater than 1.

6. The light-collecting element according to claim 5, characterized in that, The opening length D of each of the aspherical microstructures (12) on the first plane (111) is less than 20 μm.

7. The light-collecting element according to claim 1, characterized in that, Multiple aspherical microstructures (12) are arranged in an array on the first plane (111), the aspherical microstructures (12) are configured in at least two columns, and the aspherical microstructures (12) in adjacent columns are staggered.

8. The light-collecting element according to claim 1, characterized in that, The aspherical microstructure (12) is an aspherical optical lens.

9. The light-collecting element according to claim 1, characterized in that, The aspherical microstructure (12) is fabricated using a UV process.

10. A photodetector, characterized in that, It includes a photodetector (2) and a light-collecting element (1) as described in any one of claims 1 to 9, wherein the photodetector (2) is configured to receive light emitted from the light-collecting element (1).

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