Light collecting element and photoelectric detector
By setting up an aspherical microstructure on the light collecting element of the photodetector, the total reflection of the incident light from a large angle is realized, which solves the problem of low collection efficiency of the photodetector for large angle light and improves the detection accuracy.
Patent Information
- Application Number
- CN202422233627.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-09-11
AI Technical Summary
The light collecting elements of existing photodetectors cannot effectively collect incident light from large angles, resulting in a decrease in photoelectric collection efficiency and a decrease in detection accuracy.
A plurality of aspherical microstructures are arranged on the light collecting element of the photodetector, and the large-angle incident light is converted into small-angle light by total reflection to improve the light contact area and collection efficiency.
The light collection efficiency of the light collection element and the detection accuracy of the photodetector are greatly improved, and it can effectively collect and detect light from any angle.
Smart Images
Figure CN223157546U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical detection, in particular to a light collecting element and a photodetector. Background Technique
[0002] At present, the detection of light is extremely useful in production and life. Photodetectors can be used for light intensity judgment of products, light leakage detection, wavelength analysis, etc., with a wide range of uses. In the research and development field of photodetectors, the ability to collect light is one of the key factors to improve the performance of the device. An ideal photodetector should have a high sensitivity to light to achieve an excellent signal-to-noise ratio. In addition, the performance of a photodetector depends not only on its precise detection ability for small-angle incident light, but also on its accurate response to large-angle incident light.
[0003] At present, the light collecting elements of photodetectors on the market are mostly planar structures, which cannot effectively collect light from different angles, especially for large-angle incident light. As the incident angle increases, the proportion of reflected light increases, resulting in a decrease in the light incident on the photoelectric receiver, leading to a reduction in the photoelectric collection efficiency and a decrease or inaccuracy in the detection accuracy of the photodetector.
[0004] In view of this, it is necessary to provide a light collecting element and a photodetector to solve the above problems. Content of the Utility Model
[0005] The purpose of the utility model is to provide a light collecting element with high light collecting efficiency.
[0006] To achieve the above purpose, the utility model provides a light collecting element, which is applied to a photodetector and includes: a body, the body includes a first plane and a second plane arranged oppositely, on the body, a plurality of aspherical microstructures are formed to protrude from the first plane in a direction away from the second plane, the aspherical microstructures include a light incident surface facing outward and a reflection surface facing inward, and a light exit surface located on the first plane; the aspherical microstructures are configured to perform total reflection on the incident light entering the light incident surface and then emit it from the second plane.
[0007] Optionally, the plurality of aspherical microstructures are microstructures of the same size, or the plurality of aspherical microstructures are microstructures that are proportionally enlarged or reduced.
[0008] Optionally, the surface formula of the aspherical microstructure located on the first plane is:
[0009]
[0010] Wherein, c = 1 / (0.002 * β); k = -0.9; α1 = 100 / β 2 ; β is the proportionality coefficient between different aspherical microstructures and the aspherical microstructure as a reference.
[0011] Optionally, the value range of β is [-15, 15].
[0012] Optionally, it is defined that the light-emitting surface of the aspherical microstructure on the first plane has an opening length D, and in the height direction perpendicular to the first plane, the aspherical microstructure has a height H, and the ratio of the height H to the opening length D is greater than 1.
[0013] Optionally, the opening length D of each aspherical microstructure on the first plane is less than 20 um.
[0014] Optionally, multiple aspherical microstructures are arranged in an array on the first plane, the aspherical microstructures are arranged in at least two columns, and the adjacent two columns of aspherical microstructures are arranged in a staggered manner.
[0015] Optionally, the aspherical microstructure is an aspherical optical lens.
[0016] Optionally, the aspherical microstructure is processed by a UV process.
[0017] Another object of the present invention is to provide a photodetector having the above light-gathering element, and the detection accuracy of the photodetector is high.
[0018] To achieve the above object, the present invention provides a photodetector, including a photoreceiver and the above light-gathering element, and the photoreceiver is configured to receive the light emitted from the light-gathering 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 the utility model is provided with a plurality of aspheric microstructures protruding from the first plane on the first plane of the body, so that the incident light enters the light collecting element from the aspheric microstructure, thereby increasing the light contact area of the light collecting element. Moreover, through the aspheric surface of the aspheric microstructure, the light incident on the first plane at a large angle can be converted into a relatively small angle incident light entering the aspheric microstructure. The incident light entering the aspheric microstructure from the light incident surface can undergo lossless total reflection on the reflection surface on the opposite side of the light incident surface, thereby making the incident light deflected into a small angle light emitted from the light emitting surface into the body of the light collecting element. After the light is refracted in the body, it is emitted at a smaller angle on the second plane to reduce the incident angle entering the photoelectric receiver, so as to facilitate the photoelectric receiver to receive and detect, thereby greatly improving the light collecting efficiency of the light collecting element, fundamentally improving the detection accuracy of the photoelectric detector for large angle light, so that the photoelectric detector can detect light at any angle, and improve the detection accuracy of the photoelectric detector. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the structure of a light collecting element according to an embodiment of the utility model;
[0022] Figure 2 yes Figure 1 Schematic diagram of the structure of the non-spherical microstructure;
[0023] Figure 3 yes Figure 1 The optical path diagram of the light collecting element shown;
[0024] Figure 4 is a light path diagram of a photoelectric detector in the prior art;
[0025] Figure 5 yes Figure 4 A diagram showing the light collection efficiency of the light collection element in the photodetector shown;
[0026] Figure 6 This is a light path diagram of a photoelectric detector according to an embodiment of the utility model;
[0027] Figure 7 yes Figure 6 A graph of the light collection efficiency of the light collection element in the photodetector shown.
[0028] Description of reference numerals:
[0029] Photodetector 100;
[0030] Light collecting element 1, body 11, first plane 111, second plane 112, aspherical microstructure 12, light incident surface 121, reflecting surface 122;
[0031] Photoelectric receiver 2. Detailed implementation manners
[0032] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0033] Here, it should be noted that in order to avoid obscuring the present utility model due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present utility model are shown in the drawings, while other details less related to the present utility model are omitted.
[0034] In addition, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.
[0035] Please refer to Figures 1 to 7 As shown, an embodiment of the present utility model provides a light collecting element 1, which is applied to a photodetector 100 and is used to collect light and transmit the light to a photoreceiver 2.
[0036] Please refer to 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 microstructures 12 are integrally formed. In other embodiments, the body 11 and the aspherical microstructures 12 may also be formed by combination.
[0038] The body 11 includes a first plane 111 and a second plane 112 which are oppositely arranged. Among them, the first plane 111 faces the light source, and the second plane 112 faces the photoreceiver 2. That is, in the body 11, after the light is transmitted from the first plane 111 to the second plane 112, it exits from the second plane 112 to the photoreceiver 2.
[0039] On the body 11, a plurality of aspherical microstructures 12 are formed to protrude from the first plane 111 in a direction away from the second plane 112. That is to say, the aspherical microstructures 12 are disposed on the first plane 111 and protrude from the first plane 111.
[0040] Please refer to Figure 2 and Figure 3As shown, the aspherical microstructure 12 includes a light incident surface 121 facing outward, a reflection surface 122 facing inward, and a light exit surface located on the first plane 111. Among them, both the light incident surface 121 and the reflection surface 122 are aspherical surfaces protruding from the first plane 111. However, the light incident surface 121 is located on the outside and is configured to receive light, while the reflection surface 122 is located on the inside and is configured to reflect light, and the light exit surface is a plane provided on the first plane 111.
[0041] By disposing a plurality of aspherical microstructures 12 protruding from the first plane 111 on the first plane 111 of the body 11, incident light enters the light collecting element 1 from the protruding aspherical microstructures 12, thereby increasing the light contact area of the light collecting element 1.
[0042] Define the incident angle of an incident light ray incident on the first plane 111 as the first incident angle, and the incident angle of this incident light ray incident on the light incident surface 121 as the second incident angle. The second incident angle is smaller than the first incident angle. For example, when the incident angle of an incident light ray incident on the first plane 111 is 55°, since the light incident surface 121 of the aspherical microstructure 12 is a curved surface protruding from the first plane 111, the angle between this incident light ray and the normal of the light incident surface 121 is less than 55°. For example, the incident angle of this incident light ray incident on the light incident surface 121 of the aspherical microstructure 12 can be about 42 - 48°. That is, through the aspherical light incident surface 121, the incident light ray with a large first incident angle can be transformed into an incident light ray with a relatively small second incident angle. Define this transformation process as the first transformation.
[0043] The incident light ray after the first transformation enters the interior of the aspherical microstructure 12 from the light incident surface 121 of the aspherical microstructure 12 at a relatively small second incident angle. And a lossless total reflection occurs on the reflection surface 122 on the opposite side of the light incident surface 121 to form a total reflection light ray. The total reflection light ray enters the body 11 from the light exit surface, and then exits from the second plane 112 to reduce the incident angle entering the photoelectric receiver 2. That is, after being reflected by the reflection surface 122 of the aspherical microstructure 12, the incident light ray with the second incident angle is transformed into a total reflection light ray with a smaller third incident angle, enters the body 11 from the light exit surface, and exits from the second plane 112 and is received by the photoelectric receiver 2 to reduce the incident angle of the light entering the photoelectric receiver 2, thereby greatly improving the light collection efficiency of the light collecting element 1.
[0044] Furthermore, the surface formula of the aspherical microstructure 12 is:
[0045]
[0046] Among them, c = 1 / (0.002 * β); k = -0.9; α1 = 100 / β 2 ; β is the proportionality coefficient between different aspherical microstructures 12 and the aspherical microstructure 12 as a reference.
[0047] Furthermore, the value range of β is [-15, 15].
[0048] It is defined that the light-emitting surface of the aspherical microstructure 12 on the first plane 111 has an opening length D. In the height direction perpendicular to the first plane 111, the aspherical microstructure 12 has a height H, and the ratio of the height H to the opening length D is greater than 1. With such a setting, it is ensured that the aspherical microstructure 12 can effectively collect and guide light, increase the light contact area, and improve the light collection efficiency. Moreover, the reflection loss of light on the reflecting surface 122 can be reduced, and lossless total reflection can be achieved. Because light is more likely to enter the light collection 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 um. With such a setting, the size of the aspherical microstructure 12 is reduced, so that multiple aspherical microstructures 12 can be arranged on the first plane 111, thereby improving the 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, multiple aspherical microstructures 12 are arranged in an array on the first plane 111. The aspherical microstructures 12 are arranged in at least two columns, and the adjacent two columns of aspherical microstructures 12 are arranged in a staggered manner. With such a setting, the aspherical microstructures 12 can more effectively cover the first plane 111, thereby increasing the light collection area of the light collection element 1. Moreover, the staggered arrangement helps to avoid the occlusion of light between adjacent aspherical microstructures 12 and achieve a more uniform light distribution. The microstructures arranged in an array can maximize the utilization of the space of the first plane 111 and improve the space utilization rate. Of course, in other embodiments, multiple aspherical microstructures 12 can also be arranged in other forms. For example, hexagonal array arrangement or other arrangements.
[0053] In this embodiment, the shapes of multiple aspherical microstructures 12 are the same. The curve of the light-incident surface 121 of the aspherical microstructure 12 is a parabola or approximately a parabola. With such a setting, the incident light can be accurately focused, enhancing the light collection ability. In addition, unnecessary light scattering can be reduced, the background noise is lowered, and the signal-to-noise ratio is improved.
[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 the aspherical microstructures 12 are microstructures of the same size. In other embodiments, the plurality of the aspherical microstructures 12 may also be microstructures that are enlarged or reduced in equal proportion.
[0056] Please refer to Figures 4 to 7 As shown, an embodiment of the present utility model further provides a photodetector 100, which includes the above-mentioned light collecting element 1 and a photoelectric receiver 2. The photoelectric receiver 2 is configured to receive the light rays emitted from the light collecting element 1. Since the light collecting unit of the present utility model can not only collect incident light rays at small angles, but also effectively collect incident light rays at medium and large angles, thereby increasing the amount of light rays received by the photoelectric receiver 2, and further improving the photometric accuracy.
[0057] Combined with Figures 3 to 7 , the following description will explain the optical path diagram of the light rays passing through the light collecting element 1 to the photoelectric receiver 2, and by comparing the optical path diagram of the ordinary photodetector 100' in the prior art and the optical path diagram of the photodetector 100 of the present utility model, the process of the light collecting element 1 of the present utility model improving the light collecting efficiency will be described in detail.
[0058] Please refer to Figure 4 and Figure 5 As shown, in the prior art, the incident surface of the ordinary light collecting element 1' is a first plane. When the incident light rays enter the ordinary light collecting element 1', most of the incident light rays are reflected on the first plane 111, and as the angle of the incident light rays increases, the proportion of the reflected light rays increases, so that most of the incident light rays cannot enter the ordinary light collecting element 1', reducing the collection efficiency of the ordinary light collecting element 1'. Moreover, the ordinary photoelectric receiver 2' cannot receive the light rays of the ordinary laser element, resulting in a reduction in the test accuracy of the photodetector, and the inability to effectively measure large-angle light rays.
[0059] In the prior art, the incident surface of the ordinary light collecting element 1 is the first plane 111. Define the incident angle of an incident light ray incident on the first plane 111 as the first incident angle. That is, in the prior art, the angle at which the incident light ray enters the body 11 of the ordinary light collecting element 1 is the first incident angle.
[0060] When the incident light enters the ordinary light collector 1 at the first incident angle, most of the incident light is reflected on the first plane 111. Moreover, as the proportion of the reflected light increases with the increase in the angle of the incident light, most of the incident light cannot enter the light collector 1, reducing the collection efficiency of the light collector 1, decreasing the test accuracy of the optoelectronic tester, and moreover, it is impossible to effectively measure large-angle light rays.
[0061] Please refer to Figure 3 、 Figure 6 and Figure 7 as shown, which is the optical path diagram of the optoelectronic detector 100 of the present utility model. In the present utility model, the light incident surface 121 is the outer peripheral surface of the aspherical surface of the aspherical micro-structure 12.
[0062] When the incident angle of the incident light is less than 40°, at least part of the incident light enters the aspherical micro-structure 12 from the light incident surface 121, undergoes lossless total reflection on the reflection surface 122 of the aspherical micro-structure 12, and then exits from the light exit surface to the main body 11, and then exits from the second plane 112 of the main body 11 to reduce the incident angle entering the optoelectronic receiver 2. That is, small-angle incident light can directly exit from the light exit surface to the inside of the main body 11 after refraction. That is, the incident light as the main body 11 can be all refracted light rays after refraction.
[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 micro-structure 12 from the light incident surface 121, and undergoes lossless total reflection on the reflection surface 122 on the opposite side of the light incident surface 121 to form total reflection light rays. The total reflection light rays enter the main body 11 from the light exit surface at an incident angle less than 40°, and exit from the second plane 112 of the main body 11 and are received by the optoelectronic receiver 2 to reduce the incident angle entering the optoelectronic receiver 2. That is, inside the aspherical micro-structure 12, through the reflection of the reflection surface 122, the incident light with the second incident angle is transformed into total reflection light rays with a smaller third incident angle and enters the main body 11, and smaller-angle light rays exit from the second plane 112, thereby reducing the incident angle entering the optoelectronic receiver 2 and facilitating the optoelectronic receiver 2 to receive light.
[0064] Since the present utility model is provided with a plurality of aspherical micro-structures 12 protruding from the first plane 111, the light rays with a large-angle (first incident angle) incident angle are transformed into incident light rays with a relatively smaller angle (second incident angle) through the light incident surface 121, and after undergoing total reflection on the reflection surface 122 of the aspherical micro-structure 12, light rays with a smaller angle (third incident angle) exit from the light exit surface to the inside of the main body 11 of the light collector 1. That is, the large-angle incident light undergoes two transformations and enters the incident surface of the main body 11 of the light collector 1 at a smaller angle. With such a setting, the light collection efficiency of the light collector 1 can be greatly improved.
[0065] The light entering the main body 11 emits light at a smaller angle from its second plane 112, thereby reducing the incident angle of the light entering the photoelectric receiver 2, facilitating the photoelectric receiver 2 to receive the light, and further improving the light collection efficiency and detection accuracy of the photodetector.
[0066] Please refer to Figure 5 and Figure 7 As shown, taking the first incident angle of 80° as an example, the light collection efficiency on the ordinary light collection element 1 shown in Figure 5 is less than 40%, while the light collection efficiency on the light collection element 1 shown in Figure 7 can be increased to 81%, and the light collection efficiency is increased by more than twice.
[0067] In summary, the light collection element 1 of the present utility model is provided with a plurality of aspherical microstructures 12 protruding from the first plane 111 on the first plane 111 of the main body 11, so that the incident light enters the light collection element 1 from the aspherical microstructures 12, thereby increasing the light contact area of the light collection element 1. And, through the aspherical surface of the aspherical microstructures 12, the light with a large incident angle that should have been incident on the first plane 111 can be changed into incident light with a relatively small angle and enter the aspherical microstructures 12. By setting the aspherical surface as the light incident surface 121 facing outward and the reflection surface 122 facing inward, the large-angle incident light entering the aspherical microstructures 12 from the light incident surface 121 can undergo lossless total reflection on the reflection surface 122 on the opposite side of the light incident surface 121. Furthermore, the large-angle incident light is deflected on the reflection surface 122 and deflected into light with a small angle and exits from the light exit surface into the main body 11 of the light collection element 1. Inside the main body 11, the light exits at a smaller angle after refraction to facilitate the photoelectric receiver 2 to receive and detect, thereby greatly improving the light collection efficiency of the light collection element 1, fundamentally improving the detection accuracy of the photodetector 100 for large-angle light, enabling the photodetector 100 to receive light at any angle, and improving the detection accuracy of the photodetector 100.
[0068] The above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present utility model.
Claims
1. A light collecting element, applied to a photodetector, characterized in that, Comprising: A body (11), the body (11) includes a first plane (111) and a second plane (112) arranged oppositely. On the body (11), a plurality of aspherical microstructures (12) are formed to protrude from the first plane (111) in a direction away from the second plane (112). The aspherical microstructures (12) include a light incident surface (121) facing outward and a reflection surface (122) facing inward, and a light exit surface located on the first plane (111). The aspherical microstructures (12) are configured to totally reflect the incident light entering from the light incident surface (121) and then emit it from the second plane (112).
2. The light collecting element according to claim 1, wherein The plurality of aspherical microstructures (12) are microstructures of the same size, or the plurality of aspherical microstructures (12) are microstructures that are enlarged or reduced in equal proportion to each other.
3. The light collecting element according to claim 2, wherein, The surface formula of the aspherical microstructures (12) located on the first plane (111) is: Among them, c = 1 / (0.002 * β); k = -0.9; α1 = 100 / β 2 ; β is the proportionality coefficient between different aspherical microstructures (12) and the aspherical microstructure (12) used as a reference.
4. The light collecting element according to claim 3, wherein The value range of β is [-15, 15].
5. The light collecting element according to claim 1, wherein It is defined that the light exit surface of the aspherical microstructures (12) on the first plane (111) has an opening length D, and in the height direction perpendicular to the first plane (111), the aspherical microstructures (12) have a height H, and 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 aspherical microstructure (12) on the first plane (111) is less than 20um.
7. The light collecting element according to claim 1, characterized in that, The plurality of aspherical microstructures (12) are arranged in an array on the first plane (111), the aspherical microstructures (12) are arranged in at least two columns, and the adjacent two columns of the aspherical microstructures (12) are arranged in a staggered manner.
8. The light collecting element according to claim 1, characterized in that, The aspherical microstructures (12) are aspherical optical lenses.
9. The light collecting element according to claim 1, wherein, The aspherical microstructures (12) are processed by a UV process.
10. A photodetector, characterized in that, Comprising a photoelectric receiver (2) and a light collecting element (1) according to any one of claims 1 to 9, the photoelectric receiver (2) is configured to receive the light emitted from the light collecting element (1).