Bent coplanar waveguide and back-illuminated photodetector

Abstract

The application provides a deflection type coplanar waveguide and a back-illumination photoelectric detector, the deflection type coplanar waveguide is applied to the back-illumination photoelectric detector, and the deflection type coplanar waveguide is characterized in that the deflection type coplanar waveguide comprises a substrate, a conducting band is arranged on the substrate, the conducting band is used for transmitting an electric signal, and the conducting band extends from a first surface of the substrate to a second surface of the substrate adjacent to the first surface, so that the electric signal is transmitted from the first surface to the second surface. The deflection type coplanar waveguide and the back-illumination photoelectric detector provided by the application are simple in structure, convenient to use, can effectively change the transmission direction of the electric signal, optimize the layout of the back-illumination photoelectric detector, and improve the signal transmission effect.

Description

Technical Field

[0001] This application relates to the field of photoelectric detection technology, and in particular to a deflection type coplanar waveguide and a back-illuminated photodetector. Background Technology

[0002] A photodetector is a device that converts light signals into electrical signals. When light shines on a photoelectric conversion element, photogenerated carriers are generated. These carriers are collected by an electric field to form an electrical signal output. Photodetectors are widely used in optical communication, optical measurement, imaging, spectral analysis, biomedicine, security monitoring and other fields.

[0003] Back-illuminated photodetectors are a type of photodetector commonly used for high-sensitivity light detection. Unlike traditional front-illuminated photodetectors, back-illuminated photodetectors are illuminated from the reverse side. This allows photons to more easily penetrate the material layers of the detector, reach the photoelectric conversion element, and generate electron-hole pairs, thereby improving photoelectric conversion efficiency. Compared to photodetectors that receive light signals from the front, back-illuminated photodetectors have higher responsivity, lower dark current, and lower noise. They are suitable for applications with high requirements for signal-to-noise ratio and detection sensitivity, such as astronomical observation, infrared imaging, and high-speed communication.

[0004] A typical back-illuminated photodetector structure includes an incident optical fiber, a photoelectric conversion chip, a conventional coplanar waveguide, and a radio frequency (RF) output port. The photoelectric conversion chip is mounted on the conventional coplanar waveguide, which is connected to the RF output port. External light is introduced through the incident optical fiber and illuminates the photoelectric conversion chip, which converts the optical signal into an electrical signal. This signal is then transmitted through the conventional coplanar waveguide to the RF output port for measurement and calculation. To facilitate user operation and meet the installation layout requirements of back-illuminated photodetectors, the incident optical fiber and the RF output port need to be positioned opposite each other, and the introduced light needs to be perpendicular to the photoelectric conversion chip for accurate and effective photoelectric conversion. However, because the signal transmission direction of the conventional coplanar waveguide is only in one plane, the light illuminating the photoelectric conversion chip is converted into an electrical signal and transmitted along the conventional coplanar waveguide in a direction perpendicular to the incident optical fiber. This does not meet the aforementioned structural requirements. Therefore, there is an urgent need for a coplanar waveguide that can change the signal transmission direction. Summary of the Invention

[0005] In view of this, the purpose of this application is to propose a deflection-type coplanar waveguide and a back-illuminated photodetector to solve the above-mentioned technical problems.

[0006] A first aspect of this application provides a deflection-type coplanar waveguide for use in a back-illuminated photodetector, characterized in that it comprises: a substrate, wherein a conductive strip is provided on the substrate, the conductive strip being used to transmit electrical signals, the conductive strip extending from a first surface of the substrate to a second surface of the substrate adjacent to the first surface, so that the electrical signals are transmitted from the first surface to the second surface.

[0007] In some embodiments, the included angle between the first surface and the second surface is less than or equal to 90°.

[0008] In some embodiments, the distance between the edge of the second surface away from the first surface and the first surface is 'a', the length of the first surface is 'b', and the included angle is greater than arctan(a / b).

[0009] In some embodiments, the conductor includes a first ground wire, a signal wire, and a second ground wire arranged at intervals.

[0010] A second aspect of this application provides a back-illuminated photodetector, comprising: a housing; an incident optical fiber penetrating the sidewall of the housing for guiding light from outside the housing into the housing; a support stage disposed within the housing, opposite to the incident optical fiber, wherein the sidewall of the support stage near the incident optical fiber is provided with a deflection-type coplanar waveguide as described in the first aspect above, and a photoelectric conversion chip is provided on the side of the deflection-type coplanar waveguide near the incident optical fiber, the incident optical fiber being perpendicular to the photoelectric conversion chip, and the photosensitive layer of the photoelectric conversion chip being disposed facing the incident optical fiber, so that the light perpendicularly irradiates the photoelectric conversion chip and is converted into an electrical signal; the deflection-type coplanar waveguide includes A substrate has a conductive strip on its side near the photoelectric conversion chip. The conductive strip abuts against the photoelectric conversion chip and extends from the bottom side of the substrate to the top edge of the substrate away from the incident optical fiber, so that the electrical signal can be transmitted to the top surface of the substrate through the conductive strip. A transmission line is provided on the top surface of the support stage. One end of the transmission line is connected to the conductive strip on the top surface of the substrate by a metal wire, so that the electrical signal can be transmitted from the conductive strip to the transmission line. An RF output port penetrates the side wall of the housing opposite to the incident optical fiber and is connected to the other end of the transmission line to transmit the electrical signal to the outside of the housing.

[0011] In some embodiments, the opposite sidewalls of the housing are provided with a first through hole and a second through hole, the first through hole being used to allow the incident optical fiber to pass through the sidewall of the housing, and the second through hole being used to allow the radio frequency output port to pass through the sidewall of the housing and connect to the transmission line.

[0012] In some embodiments, there are multiple conductor strips, and each conductor strip is connected to the transmission line via a metal wire.

[0013] In some embodiments, the sidewall of the support stage is provided with a stepped structure, which is positioned toward the incident optical fiber to accommodate the deflection type coplanar waveguide.

[0014] In some embodiments, the housing includes a support plate located below the incident optical fiber, with a groove on its top for supporting the incident optical fiber.

[0015] In some embodiments, a base is provided on the lower part of the housing, and a U-shaped groove is provided on the base for connecting bolts to fix the back-illuminated photodetector.

[0016] As can be seen from the above, this application provides a deflection-type coplanar waveguide and a back-illuminated photodetector. By setting a substrate to carry the conductive strip and setting the conductive strip to transmit electrical signals, the conductive strip extends from the first surface of the substrate to the second surface of the substrate adjacent to the first surface, so that the electrical signal is transmitted from the first surface to the second surface. This can change the transmission direction of the electrical signal. Applying this deflection-type coplanar waveguide to a back-illuminated photodetector is beneficial to optimizing the layout of the back-illuminated photodetector. The incident light can be perpendicular to the first surface of the substrate, and the RF output port can be connected to the conductive strip on the second surface of the substrate, so that the incident fiber and the RF output port can be arranged opposite to each other, simplifying the device structure and improving the signal transmission effect. This deflection-type coplanar waveguide and back-illuminated photodetector has a simple structure, is easy to use, and can effectively change the transmission direction of electrical signals, optimize the layout of the back-illuminated photodetector, and improve the signal transmission effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of the first back-illuminated photodetector in the related technology;

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of the second type of back-illuminated photodetector in the related technology;

[0020] Figure 3 This is a schematic diagram of the structure of the first type of deflection coplanar waveguide according to an embodiment of this application;

[0021] Figure 4 for Figure 3 Simulation diagram of signal transmission performance of a mid-biased coplanar waveguide;

[0022] Figure 5 This is a schematic diagram of the structure of the second type of deflected coplanar waveguide according to an embodiment of this application;

[0023] Figure 6 for Figure 5 Simulation diagram of signal transmission performance of a mid-biased coplanar waveguide;

[0024] Figure 7 This is a schematic diagram of the structure of the third type of deflection coplanar waveguide according to an embodiment of this application;

[0025] Figure 8 for Figure 7 Simulation diagram of signal transmission performance of a mid-biased coplanar waveguide;

[0026] Figure 9 This is a schematic diagram of the structure of the fourth type of deflection coplanar waveguide according to an embodiment of this application;

[0027] Figure 10 for Figure 9 Simulation diagram of signal transmission performance of a mid-biased coplanar waveguide;

[0028] Figure 11 This is a schematic cross-sectional view of a back-illuminated photodetector according to an embodiment of this application.

[0029] Figure 12 for Figure 11 Schematic diagram of the external structure of a mid-biased coplanar waveguide;

[0030] Figure 13 for Figure 11 A schematic diagram of the external structure of the middle shell.

[0031] Reference numerals in the attached figures: 1. Deflection type coplanar waveguide; 1-1. Substrate; 1-2. Conductor strip; 1-3. First surface; 1-4. Second surface; 1-5. First ground wire; 1-6. Signal line; 1-7. Second ground wire; 2. Housing; 2-1. First through hole; 2-2. Second through hole; 3. Incident optical fiber; 4. Photoelectric conversion chip; 5. Transmission line; 6. Metal wire; 7. RF output port; 8. Support platform; 8-1. Stepped structure; 9. Support plate; 9-1. Groove; 10. Base; 10-1. U-shaped groove; 11. Reflector; 12. Traditional coplanar waveguide. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0033] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] A photodetector is a device that converts light signals into electrical signals. When light shines on a photoelectric conversion element, photogenerated carriers are generated. These carriers are collected by an electric field to form an electrical signal output. Photodetectors are widely used in optical communication, optical measurement, imaging, spectral analysis, biomedicine, security monitoring and other fields.

[0035] Back-illuminated photodetectors are a type of photodetector commonly used for high-sensitivity light detection. Unlike traditional front-illuminated photodetectors, back-illuminated photodetectors are illuminated from the reverse side. This allows photons to more easily penetrate the material layers of the detector, reach the photoelectric conversion chip, and generate electron-hole pairs, thereby improving photoelectric conversion efficiency. Compared to photodetectors that receive light signals from the front, back-illuminated photodetectors have higher responsivity, lower dark current, and lower noise. They are suitable for applications with high requirements for signal-to-noise ratio and detection sensitivity, such as astronomical observation, infrared imaging, and high-speed communication.

[0036] A typical back-illuminated photodetector structure includes an incident optical fiber, a photoelectric conversion chip, a conventional coplanar waveguide, and an RF output port. The photoelectric conversion chip is mounted on the conventional coplanar waveguide, which is connected to the RF output port. External light is introduced through the incident optical fiber and illuminates the photoelectric conversion chip. The photoelectric conversion chip converts the optical signal into an electrical signal, which is then transmitted through the conventional coplanar waveguide to the RF output port for measurement and calculation. To facilitate user operation and meet the installation layout requirements of back-illuminated photodetectors, the incident optical fiber and the RF output port need to be positioned opposite each other, and the introduced light needs to be perpendicular to the photoelectric conversion chip for accurate and effective photoelectric conversion. However, because the signal transmission direction of the conventional coplanar waveguide is only in one plane, the light that is illuminating the photoelectric conversion chip is converted into an electrical signal and transmitted along the conventional coplanar waveguide in a direction perpendicular to the incident optical fiber, which does not meet the aforementioned structural requirements.

[0037] In related technologies, to address the issue of the relative arrangement of the incident optical fiber and the radio frequency output port, the structure of back-illuminated photodetectors has been improved, for example... Figure 1 As shown, a conventional coplanar waveguide 12 is arranged on the side of the support platform 8, and the photoelectric conversion chip 4 is attached to the conventional coplanar waveguide 12. The incident optical fiber 3 is perpendicular to the photodetector chip. A transmission line 5 is arranged on the top surface of the support platform 8. One end of the transmission line 5 is connected to the RF output port 7, and the other end is connected to the conventional coplanar waveguide 12. In this way, the incident optical fiber 3 and the RF output port 7 can be arranged opposite each other. However, the guide strip 1-2 of the transmission line 5 and the conventional coplanar waveguide 12 are connected by a metal wire 6. Because the guide strip 1-2 of the conventional coplanar waveguide 12 is only on one plane, the metal wire 6 is too long and has a large bending arc. Figure 1 As shown, in actual radio frequency signal transmission, the loss is extremely high, which seriously affects the responsivity and bandwidth of the photodetector, resulting in a low yield.

[0038] There are also some back-illuminated photodetectors, such as Figure 2 As shown, a conventional coplanar waveguide 12 is set on the top surface of the support platform 8, and the photoelectric conversion chip 4 is attached to the conventional coplanar waveguide 12. The incident optical fiber 3 is parallel to the photodetector chip. The conventional coplanar waveguide 12 is connected to the radio frequency output port 7. In addition, multiple reflectors 11 are set to reflect light so that the light can be perpendicularly irradiated onto the photoelectric conversion chip 4, ensuring the photoelectric conversion effect. It can also make the incident optical fiber 3 and the radio frequency output port 7 set relative to each other. However, the introduction of reflectors 11 increases the difficulty of light alignment, increases uncontrollable factors, and also increases costs. During the process of incident light reaching the photosensitive surface of the chip through the reflectors, the optical signal is lost, and the deformation of the external shell will also affect the normal transmission of the optical path to a certain extent, resulting in poor stability.

[0039] Especially for high-power, high-bandwidth back-illuminated photodetectors, the chip electrode layer and photosensitive layer are extremely small, and traditional packaging designs introduce significant transmission losses and uncertainties. Therefore, there is an urgent need for a coplanar waveguide that can change the signal transmission direction to optimize the structure of back-illuminated photodetectors and improve signal transmission performance and stability.

[0040] The following describes specific embodiments in conjunction with... Figures 1 to 13 The technical solution of this application will be described in detail below.

[0041] Some embodiments of this application provide a deflection-type coplanar waveguide 1, applied to a back-illuminated photodetector, such as... Figure 3As shown, it includes: a substrate 1-1, on which a conductive strip 1-2 is provided, the conductive strip 1-2 being used to transmit electrical signals, the conductive strip 1-2 extending from a first surface 1-3 of the substrate 1-1 to a second surface 1-4 of the substrate 1-1 adjacent to the first surface 1-3, so that the electrical signals are transmitted from the first surface 1-3 to the second surface 1-4.

[0042] Substrate 1-1 is a rigid substrate, and the material is not limited to silicon nitride, etc., to ensure structural stability. Because photoelectric detection has high sensitivity, it is easily interfered with. Setting rigid substrate 1-1 has stronger structural stability than flexible substrate 1-1, so as to avoid affecting the signal transmission effect. Substrate 1-1 is used to support conductor 1-2.

[0043] The material of the conductor strip 1-2 is, for example, gold, which has good conductivity and ductility. The conductor strip 1-2 is set up to transmit electrical signals.

[0044] The guide strip 1-2 extends from the first surface 1-3 of the substrate 1-1 to the second surface 1-4 of the substrate 1-1 adjacent to the first surface 1-3, so that the electrical signal is transmitted from the first surface 1-3 to the second surface 1-4. This can change the transmission direction of the electrical signal. Applying this deflecting coplanar waveguide 1 to a back-illuminated photodetector is beneficial to optimizing the layout of the back-illuminated photodetector. The incident light can be perpendicular to the first surface 1-3 of the substrate 1-1, and the RF output port 7 can be connected to the guide strip 1-2 on the second surface 1-4 of the substrate 1-1, so that the incident fiber 3 and the RF output port 7 can be set relative to each other. There is no need to set up components such as the reflector 11, which simplifies the device structure. There is no need for the connection of the bent metal wire 6, which improves the signal transmission effect.

[0045] The deflection-type coplanar waveguide 1 has a simple structure and is easy to use. It can effectively change the transmission direction of electrical signals, optimize the layout of back-illuminated photodetectors, and improve signal transmission performance.

[0046] In some embodiments, such as Figure 3 As shown, the conductor 1-2 includes a first ground wire 1-5, a signal wire 1-6, and a second ground wire 1-7 arranged at intervals.

[0047] The first ground wire 1-5 and the second ground wire 1-7 are respectively set on both sides of the signal line 1-6, which increases the grounding plane area. The signal line 1-6 is surrounded by the grounding plane area, which can effectively reduce the signal intensity radiated outward during transmission and generate less electromagnetic radiation.

[0048] In some embodiments, the included angle between the first surface 1-3 and the second surface 1-4 is less than or equal to 90°.

[0049] like Figure 3As shown, the angle between the first surface 1-3 and the second surface 1-4 is c. Setting the angle ≤ 90° can effectively ensure the signal transmission effect.

[0050] like Figure 3 , Figure 5 and Figure 7 As shown, three different angled coplanar waveguides 1 are presented. By designing and calculating the gap width between the ground wire and signal line 1-6, the width of signal line 1-6, and the thickness of substrate 1-1, the characteristic impedance of these three angled coplanar waveguides 1 is made to be 50Ω. The signal transmission effect is then verified using HFSS (High Frequency Structure Simulator) software. In the figure, A represents the signal input port, and B represents the meter signal output port. The simulation results are shown in Figure 4. Figure 6 and Figure 8 As shown in the figure, S(1,1) represents the ratio of the signal reflected back from port A after the input signal is input to port A to the input signal itself, i.e., the reflection coefficient. If the reflection coefficient is lower than -20dB, it indicates excellent transmission performance. S(1,2) represents the ratio of the signal output from port B after the input signal is input to port A to the input signal itself, i.e., the transmission coefficient. When the transmission coefficient is equal to 0dB, the power of the input signal at port A is equal to the power of the output signal at port B, i.e., lossless transmission. A small fluctuation in the transmission coefficient around 0dB indicates excellent transmission performance.

[0051] like Figure 3 As shown, the included angle of the deflected coplanar waveguide 1 is 90°, and the corresponding simulation results are as follows. Figure 4 As shown, the S(1,1) curve is below -20dB in the frequency range from 0GHz to 100GHz, and the S(1,2) curve is 0dB in the frequency range from 0GHz to 100GHz. This indicates that the deflected coplanar waveguide 1 can achieve lossless signal transmission from low frequency to high frequency and has good transmission effect.

[0052] like Figure 5 As shown, the included angle of the deflected coplanar waveguide 1 is 135°, and the corresponding simulation results are as follows. Figure 6 As shown, the S(1,1) curve is between -8dB and -10dB at frequencies from 0GHz to 100GHz, and the S(1,2) curve is between 0dB and -1dB at frequencies from 0GHz to 100GHz. This indicates that the deflection type coplanar waveguide 1 has a large loss and is not suitable as a radio frequency transmission medium. The reason is speculated to be that the thickness of the conductor strip 1-2 near port B is insufficient.

[0053] like Figure 7 As shown, the included angle of the deflected coplanar waveguide 1 is 45°, and the corresponding simulation results are as follows. Figure 8As shown, the S(1,1) curve is below -20dB in the frequency range from 0GHz to 100GHz, and the S(1,2) curve is 0dB in the frequency range from 0GHz to 100GHz. This indicates that the deflected coplanar waveguide 1 can achieve lossless signal transmission from low frequency to high frequency. Therefore, setting the included angle c≤90° can ensure the signal transmission effect.

[0054] In some embodiments, the distance between the edge of the second surface 1-4 away from the first surface 1-3 and the first surface 1-3 is a, the length of the first surface 1-3 is b, and the included angle is greater than arctan(a / b).

[0055] The distance between the edge of the second surface 1-4 away from the first surface 1-3 and the first surface 1-3 is 'a', meaning the thickness of the substrate 1-1 is 'a'. The length of the first surface 1-3 is 'b', meaning the length of the substrate 1-1 is 'b'. arctan(a / b) is the angle between the diagonals of the rectangle formed by length 'b' and width 'a'. Figure 9 As shown, the angle c between the first surface 1-3 and the second surface 1-4 is equal to arctan(a / b), which is 30°. Through design calculations of the gap width between the ground wire and signal line 1-6, the width of signal line 1-6, and the thickness of substrate 1-1, the characteristic impedance of this deflected coplanar waveguide 1 is made to be 50Ω. The signal transmission effect is then verified using HFSS simulation software. The simulation results are as follows: Figure 10 As shown, the S(1,1) curve is near 0dB in the frequency range from 0GHz to 100GHz, and the S(1,2) curve is less than -10dB in the frequency range from 0GHz to 100GHz. This indicates that the deflected coplanar waveguide 1 is almost completely reflected, that is, completely lost, and cannot be used for transmission. Therefore, setting the included angle c > arctan(a / b) can ensure the signal transmission effect.

[0056] Some embodiments of this application provide a method for fabricating a deflection-type coplanar waveguide 1, including: depositing a metal layer on a first surface 1-3 and a second surface 1-4 adjacent to a substrate 1-1, and forming a conductive band 1-2 on the metal layer by a patterning process, so that the conductive band 1-2 extends from the first surface 1-3 to the second surface 1-4.

[0057] The “patterning process” mentioned in the embodiments of this application includes processes such as coating photoresist, mask exposure, development, etching, and photoresist stripping. Deposition can be any one or more of sputtering, evaporation, and chemical vapor deposition. Coating can be any one or more of spraying, spin coating, and inkjet printing. Etching can be any one or more of dry etching and wet etching, without limitation.

[0058] Some embodiments of this application provide a back-illuminated photodetector, such as... Figures 11 to 13As shown, it includes: a housing 2; an incident optical fiber 3, penetrating the side wall of the housing 2, for guiding light from outside the housing 2 into the interior; a support platform 8, disposed inside the housing 2, opposite to the incident optical fiber 3, the support platform 8 having a deflection-type coplanar waveguide 1 as described in any of the above embodiments on its side wall near the incident optical fiber 3, the deflection-type coplanar waveguide 1 having a photoelectric conversion chip 4 on the side near the incident optical fiber 3, the incident optical fiber 3 being perpendicular to the photoelectric conversion chip 4, and the photosensitive layer of the photoelectric conversion chip 4 being disposed facing the incident optical fiber 3, so that the light perpendicularly irradiates the photoelectric conversion chip 4 and is converted into an electrical signal; the deflection-type coplanar waveguide 1 includes a substrate 1-1, the substrate 1-1 being near the photoelectric conversion chip 4 A guide strip 1-2 is provided on the side, which abuts against the photoelectric conversion chip 4. The guide strip 1-2 extends from the bottom side of the substrate 1-1 to the edge of the top surface of the substrate 1-1 away from the incident optical fiber 3, so that the electrical signal is transmitted to the top surface of the substrate 1-1 through the guide strip 1-2. A transmission line 5 is provided on the top surface of the support platform 8. One end of the transmission line 5 is connected to the guide strip 1-2 located on the top surface of the substrate 1-1 through a metal wire 6, so that the electrical signal is transmitted from the guide strip 1-2 to the transmission line 5. An RF output port 7 penetrates the side wall of the housing 2 opposite to the incident optical fiber 3. The RF output port 7 is connected to the other end of the transmission line 5, so as to transmit the electrical signal to the outside of the housing 2.

[0059] The housing 2 is used to protect the internal structure and prevent interference with the detection. The incident fiber 3, for example, is of type GYDXTW, but the specific type is not limited. It is used to guide the light from outside the housing 2 into the interior for conversion. The support platform 8 is used to support the deflection-type coplanar waveguide 1, the photoelectric conversion chip 4, and the transmission line 5. The photoelectric conversion chip 4, for example, is a gallium arsenide-modified single-carrier photodetector chip, including a photosensitive layer and an electrode layer. The deflection-type coplanar waveguide 1 and the photoelectric conversion chip 4 are pressed together by a chip mounter to realize the transmission of electrical signals. The substrate 1-1 has dimensions of, for example, 0.25mm*0.3mm*0.38mm, and the photoelectric conversion chip 4 has dimensions of, for example, 0.15mm*0.2mm*0.35mm. The size of the photoelectric conversion chip 4 is smaller than that of the substrate 1-1. The transmission line 5 is, for example, a common straight coplanar waveguide, which is not specifically limited. It is connected to the deflection type coplanar waveguide 1 to transmit electrical signals. The RF output port 7 has a model of, for example, SMA-K, which is not specifically limited. It is connected to the transmission line 5 to transmit electrical signals to the outside of the housing 2.

[0060] The incident optical fiber 3 is perpendicular to the photoelectric conversion chip 4, and the photosensitive layer of the photoelectric conversion chip 4 is positioned facing the incident optical fiber 3, so that the light shines perpendicularly onto the photoelectric conversion chip 4, ensuring the photoelectric conversion effect. The deflection type coplanar waveguide 1 includes a substrate 1-1, and a guide strip 1-2 is provided on the side of the substrate 1-1 near the photoelectric conversion chip 4. The guide strip 1-2 abuts against the electrode layer of the photoelectric conversion chip 4 for transmitting electrical signals. The guide strip 1-2 extends from the bottom side of the substrate 1-1 to the edge of the top surface of the substrate 1-1 away from the incident optical fiber 3, that is, from the bottom side of the substrate 1-1 to the edge of the top surface of the substrate 1-1 away from the incident optical fiber 3. The first surface 1-3 of the bottom 1-1 extends to the second surface 1-4 so that the electrical signal can be transmitted from the bottom of the first surface 1-3 to the edge of the second surface 1-4 through the conductor 1-2. This facilitates the relative arrangement of the incident fiber 3 and the RF output port 7. The relative arrangement design makes it easy for the detector to be connected in the actual link, which is practical and in line with user habits. The conductor 1-2 of the second surface 1-4 is connected to the transmission line 5 by the bonded metal wire 6. In this way, the metal wire 6 can be shorter and straighter than the design in related technologies, which greatly reduces signal transmission loss.

[0061] This back-illuminated photodetector has a simple optical path, which simplifies the components required for packaging. It does not require additional reflectors 11, etc., and has strong stability. At the same time, the metal wires 6 required for packaging are short and straight, resulting in almost no loss in radio frequency signal transmission and high detection accuracy. The final performance of the detector is almost entirely determined by the photoelectric conversion chip 4, minimizing uncontrollable variables. The packaging structure has minimal impact on signal transmission, resulting in a high yield rate.

[0062] In some embodiments, such as Figure 11 and Figure 13 As shown, the opposite sidewalls of the housing 2 are respectively provided with a first through hole 2-1 and a second through hole 2-2. The first through hole 2-1 is used to allow the incident optical fiber 3 to pass through the sidewall of the housing 2, and the second through hole 2-2 is used to allow the radio frequency output port 7 to pass through the sidewall of the housing 2 and connect to the transmission line 5.

[0063] The first through hole 2-1 and the second through hole 2-2 can be set coaxially, and there is no specific limitation. The transmission line 5 and the RF output port 7 can also be connected by the metal wire 6, and there is no specific limitation. The transmission line 5 has a better signal transmission effect and lower loss than the metal wire 6, and it is easier to change the model for connection and matching.

[0064] In some embodiments, such as Figure 12 As shown, there are multiple conductor strips 1-2, and each conductor strip 1-2 is connected to the transmission line 5 through a metal wire 6.

[0065] like Figure 12 As shown, the conductor strip 1-2 includes a first ground wire 1-5, a signal wire 1-6, and a second ground wire 1-7. Each conductor strip 1-2 is connected to the transmission line 5 through a metal wire 6 to ensure signal transmission effect.

[0066] In some embodiments, such as Figure 11 and Figure 13 As shown, the side wall of the support platform 8 is provided with a stepped structure 8-1, which is arranged towards the incident optical fiber 3 and is used to accommodate the deflection type coplanar waveguide 1.

[0067] The support platform 8 can be integrally molded with the housing 2, such as... Figure 11 and Figure 13 As shown, a stepped structure 8-1 is provided to support the deflected coplanar waveguide 1. The deflected coplanar waveguide 1 can be glued to the stepped structure 8-1 to ensure stability.

[0068] In some embodiments, such as Figure 11 and Figure 13 As shown, the housing 2 is provided with a support plate 9, which is located below the incident optical fiber 3. The top of the support plate 9 is provided with a groove 9-1, which is used to support the incident optical fiber 3.

[0069] The support plate 9 can be integrally molded with the shell 2, such as Figure 11 and Figure 13 As shown, a carrier plate 9 is provided and a groove 9-1 is provided on the carrier plate 9 to support the incident optical fiber 3 and ensure stability.

[0070] In some embodiments, such as Figure 11 and Figure 13 As shown, a base 10 is provided on the lower part of the outer side of the housing 2, and a U-shaped groove 10-1 is provided on the base 10. The U-shaped groove 10-1 is used to connect bolts to fix the back-illuminated photodetector.

[0071] The base 10 can be integrally molded with the housing 2, such as... Figure 13 As shown, two U-shaped grooves 10-1 are provided on the base 10. The U-shaped grooves 10-1 can be connected with bolts to fix the back-illuminated photodetector and ensure detection stability.

[0072] In the embodiments of this application, "film" and "layer" can be interchanged. For example, sometimes "conductive layer" can be replaced with "conductive film". Similarly, sometimes "insulating film" can be replaced with "insulating layer". The scale of the drawings in the embodiments of this application can be used as a reference in actual processes, but is not limited thereto. For example, the aspect ratio of the channel, the thickness and spacing of each film layer can be adjusted according to actual needs. The number of pixels in the display panel and the number of sub-pixels in each pixel are not limited to the quantities shown in the figures. The drawings described in the embodiments of this application are only structural schematic diagrams, and one method in the embodiments of this application is not limited to the shapes or values ​​shown in the drawings.

[0073] In the embodiments of this application, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined, but can be approximate triangles, rectangles, trapezoids, pentagons, or hexagons, etc., and may have some small deformations due to tolerances, and may have chamfers, curved edges, and other deformations.

[0074] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0075] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

Claims

1. A deflection-type coplanar waveguide, used in a back-illuminated photodetector, characterized in that, include: A substrate having a conductive strip on it for transmitting electrical signals. The conductive strip extends from a first surface of the substrate to a second surface of the substrate adjacent to the first surface, so that the electrical signals are transmitted from the first surface to the second surface. The angle between the first surface and the second surface is less than 90°. The distance between the edge of the second surface away from the first surface and the first surface is 'a'. The length of the first surface is 'b'. The angle is greater than arctan(a / b).

2. The deflection-type coplanar waveguide according to claim 1, characterized in that, The conductor includes a first ground wire, a signal wire, and a second ground wire arranged at intervals.

3. A back-illuminated photodetector, characterized in that, include: case; An incident optical fiber penetrates the side wall of the housing and is used to guide light from outside the housing into the interior. A support platform is disposed within the housing, opposite to the incident optical fiber. A deflection-type coplanar waveguide as described in claim 1 or 2 is provided on the side wall of the support platform near the incident optical fiber. A photoelectric conversion chip is provided on the side of the deflection-type coplanar waveguide near the incident optical fiber. The incident optical fiber is perpendicular to the photoelectric conversion chip, and the photosensitive layer of the photoelectric conversion chip faces the incident optical fiber, so that the light perpendicularly irradiates the photoelectric conversion chip and is converted into an electrical signal. The deflection-type coplanar waveguide includes a substrate. A guide strip is provided on the side of the substrate near the photoelectric conversion chip. The guide strip abuts against the photoelectric conversion chip and extends from the bottom side of the substrate to the top edge of the substrate away from the incident optical fiber, so that the electrical signal is transmitted through the guide strip to the top surface of the substrate. A transmission line is provided on the top surface of the support platform. One end of the transmission line is connected to the guide strip located on the top surface of the substrate via a metal wire, so that the electrical signal is transmitted from the guide strip to the transmission line. An RF output port extends through the sidewall of the housing opposite to the incident optical fiber. The RF output port is connected to the other end of the transmission line to transmit the electrical signal to the outside of the housing.

4. The back-illuminated photodetector according to claim 3, characterized in that, The housing has a first through hole and a second through hole on opposite sidewalls. The first through hole is used to allow the incident optical fiber to pass through the sidewall of the housing, and the second through hole is used to allow the radio frequency output port to pass through the sidewall of the housing and connect to the transmission line.

5. The back-illuminated photodetector according to claim 3, characterized in that, There are multiple conductive strips, and each conductive strip is connected to the transmission line via a metal wire.

6. The back-illuminated photodetector according to claim 3, characterized in that, The side wall of the support platform is provided with a stepped structure, which is oriented toward the incident optical fiber to accommodate the deflection type coplanar waveguide.

7. The back-illuminated photodetector according to claim 3, characterized in that, The housing contains a support plate located below the incident optical fiber, and has a groove on its top for supporting the incident optical fiber.

8. The back-illuminated photodetector according to claim 3, characterized in that, A base is provided on the lower part of the outer shell, and a U-shaped groove is provided on the base. The U-shaped groove is used to connect bolts to fix the back-illuminated photodetector.

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