Photodiode receiving device for receiving dual-wavelength optical signal and application thereof

Abstract

The invention discloses a photodiode receiving device for receiving dual-wavelength optical signals and application thereof. The photodiode receiving device comprises a substrate, a support, a photodiode receiving assembly and a current and voltage conversion unit. The photodiode receiving assembly comprises a beam splitter prism, a first light condensing element, a second light condensing element, a first photodiode chip and a second photodiode chip; the first photodiode chip, the second photodiode chip and the current and voltage conversion unit are arranged on the substrate; the beam splitter prism, the first light condensing element and the second light condensing element are connected to the support, the support is connected to the substrate, and transmission light signals output from the beam splitter prism sequentially pass through the first light condensing element and the first photodiode chip, and reflection light signals output from the beam splitter prism sequentially pass through the second light condensing element and the second photodiode chip. The photodiode receiving device integrates the light splitting, converging and receiving functions of optical signals, and can meet the miniaturization requirement.

Description

Technical Field

[0001] The present application relates to the field of optical communication technologies, and particularly relates to a photodiode receiving device for receiving dual-wavelength optical signals and its application. Background Art

[0002] When a laser receiver receives a multi-wavelength mixed optical signal, it should first perform beam splitting outside the laser receiver, and then use independent laser receivers to separately receive the separated optical signals. Currently, most beam splitting is performed using a filter, and the beam splitting principle can be seen in Figure 1 . The dual-wavelength mixed optical signal a is incident on the first filter 110. The first-wavelength optical signal a1 in the dual-wavelength mixed optical signal a passes through the first filter 110, and the second-wavelength optical signal a2 in the dual-wavelength mixed optical signal a is reflected by the first filter 110. The transmitted first-wavelength optical signal a1 reaches the first condenser lens 140; the second-wavelength optical signal a2 is reflected to the reflector 130, and after being reflected by the reflector 130 again, it reaches the second filter 120 and passes through the second filter 120 to reach the second condenser lens 150. The first condenser lens 140 is used to converge the first-wavelength optical signal a1, and the second condenser lens 150 is used to converge the second-wavelength optical signal a2. The converged first-wavelength optical signal a1 and second-wavelength optical signal a2 are respectively received by independent laser receivers.

[0003] The above existing technology is currently widely used, but there is a problem of large occupied space and it is difficult to meet the current miniaturization requirements. Summary of the Invention

[0004] The purpose of the present application is to provide a photodiode receiving device for receiving dual-wavelength optical signals and its application. The photodiode receiving device of the present application integrates the functions of beam splitting, converging, and receiving of optical signals, and can meet the miniaturization requirements.

[0005] On the one hand, a photodiode receiving device for receiving dual-wavelength optical signals provided by the present application includes a substrate, a bracket, a photodiode receiving component, and a current-voltage conversion unit; wherein, the photodiode receiving component further includes a beam splitting prism, a first condenser element, a second condenser element, a first photodiode chip, and a second photodiode chip;

[0006] The beam splitting prism is provided with an incident surface and an exit surface opposite to each other, as well as a beam splitting surface and a reflection surface; the beam splitting surface is disposed inside the beam splitting prism and is configured to respectively transmit and reflect two optical signals in the dual-wavelength mixed optical signal incident from the incident surface; the reflection surface is configured to change the transmission direction of the reflected optical signal reflected by the beam splitting surface, so that the reflected optical signal and the transmitted optical signal transmitted from the beam splitting surface are parallel to each other and are transmitted to the exit surface and output in parallel while maintaining a distance;

[0007] The first photodiode chip, the second photodiode chip, and the current-voltage conversion unit are disposed on a substrate, and the current-voltage conversion unit is electrically connected to the first photodiode chip and the second photodiode chip to convert the photocurrents output by the first photodiode chip and the second photodiode chip into voltage signals;

[0008] The beam splitting prism, the first condenser element, and the second condenser element are connected to a bracket, and the bracket is connected to the substrate. Moreover, the beam splitting prism, the first condenser element, the second condenser element, the first photodiode chip, and the second photodiode chip should satisfy the positional relationship: the transmitted light signal output from the beam splitting prism should sequentially pass through the first condenser element and the first photodiode chip, and the reflected light signal output from the beam splitting prism should sequentially pass through the second condenser element and the second photodiode chip.

[0009] In some specific embodiments, there are two current-voltage conversion units, which are respectively denoted as the first current-voltage conversion unit and the second current-voltage conversion unit. The first current-voltage conversion unit is electrically connected to the first photodiode chip, and the second current-voltage conversion unit is electrically connected to the second photodiode chip.

[0010] In some specific embodiments, the current-voltage conversion unit selects a transimpedance amplifier.

[0011] In some specific embodiments, the exit surface includes a first selective filtering surface and a second selective filtering surface. The first selective filtering surface and the second selective filtering surface are respectively arranged in the exit regions of the transmitted light signal and the reflected light signal on the exit surface. The first selective filtering surface is configured to only allow the transmitted light signal to pass through, and the second selective filtering surface is configured to only allow the reflected light signal to pass through.

[0012] In some specific embodiments, the spacing is 250um - 1500um.

[0013] In some specific embodiments, the beam splitting prism is composed of a straight parallelepiped prism and a right triangular prism; specifically:

[0014] Glue a rectangular surface of the straight parallelepiped prism to the inclined surface of the right triangular prism to form the beam splitting prism, and make the glued surface the beam splitting surface; in the straight parallelepiped prism, the surface connected to the beam splitting surface and facing the beam splitting surface is the incident surface, the opposite surface of the incident surface in the straight parallelepiped prism is used as the exit surface of the reflected light signal, the opposite surface of the beam splitting surface in the straight parallelepiped prism is used as the reflecting surface, and the surface opposite to the incident surface in the right triangular prism is used as the exit surface of the transmitted light signal.

[0015] Furthermore, making the glued surface the beam splitting surface includes: making a beam splitting film on the glued surface.

[0016] Furthermore, the exit surface in the straight parallelepiped prism is configured to allow only the reflected optical signal to pass through.

[0017] Furthermore, the exit surface in the right triangular prism is configured to allow only the transmitted optical signal to pass through.

[0018] Furthermore, an anti-reflection film is provided on the incident surface.

[0019] Furthermore, a reflective film is provided on the reflection surface.

[0020] Furthermore, the acute angle of the right-angled surface of the right triangular prism is equal to the acute angle of the parallelogram surface of the straight parallelepiped prism.

[0021] Still further, the right triangular prism is an isosceles right triangular prism, and the inner angle of the parallelogram surface of the straight parallelepiped prism is 45 degrees.

[0022] On the other hand, the present application also provides an application of the above photodiode receiving device in separating mixed optical signals.

[0023] Please refer to Figure 2 , which shows a schematic diagram of the optical splitting principle of the photodiode receiving device of the present application. Different from Figure 1 the principle of using a filter to split light in , the present application uses a beam splitting prism 210 to split light. Using the beam splitting surface 211 in the beam splitting prism 210, the dual-wavelength mixed optical signal a is separated into a first-wavelength optical signal a1 and a second-wavelength optical signal a2. The reflection surface 212 is used to change the transmission direction of the second-wavelength optical signal a2, so that the second-wavelength optical signal a2 and the first-wavelength optical signal a1 are output parallel to each other. Compared with Figure 1 shown in , the photodiode receiving device of the present application realizes the integration of the functions of optical signal splitting, focusing and receiving. Since there is no need to arrange optical elements such as filter films and reflection films, it can meet the miniaturization requirements.

[0024] Compared with the prior art, the beneficial effects of the present application are as follows:

[0025] The existing laser receivers do not have the functions of splitting and focusing optical signals. It is necessary to arrange optical elements such as filter films and reflection films outside the laser receiver to realize the splitting and focusing of optical signals, resulting in a large occupied space and difficulty in miniaturization. The photodiode receiving device of the present application integrates the functions of splitting, focusing and receiving optical signals. At the same time, since there is no need for external optical elements such as filter films and reflection films, it can be miniaturized and meet the TO package requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is the spectral splitting principle based on the filter in the prior art;

[0028] Figure 2 It is a schematic diagram of the spectral splitting principle of the photodiode receiving device of the present application;

[0029] Figure 3 It is a specific structural schematic diagram of the photodiode receiving component in the embodiment of the present application;

[0030] Figure 4 It is a specific structural schematic diagram of the spectral splitting prism in the embodiment of the present application;

[0031] Figure 5 It is a specific structural schematic diagram of the photodiode receiving device in the embodiment of the present application;

[0032] Figure 6 It is a layout schematic diagram of the substrate in the photodiode receiving device in the embodiment of the present application.

[0033] Reference numerals: first filter 110, second filter 120, reflector 130, first condenser lens 140, second condenser lens 150; spectral splitting prism 210, straight parallelepiped prism 210a, right triangular prism 210b, spectral splitting surface 211, reflection surface 212, incident surface 213, first band-pass filter surface 214, second band-pass filter surface 215, first condenser element 220, second condenser element 230, first photodiode chip 240, second photodiode chip 250, base 260; substrate 300, wire bonding post 310, gold wire 311, filter capacitor 320; bracket 400, connecting member 410; first current-voltage conversion unit 510, second current-voltage conversion unit 520; dual-wavelength mixed optical signal a, first-wavelength optical signal a1, second-wavelength optical signal a2. Specific Embodiments

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present application in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0035] The core component of the photodiode receiving device for receiving dual-wavelength optical signals in this application is the photodiode receiving component. For ease of understanding, the specific structure and technical principle of the photodiode receiving component in the embodiments of this application will be described in detail below in combination with Figure 2-4 the specific structure and technical principle of the photodiode receiving component in the embodiments of this application will be described in detail.

[0036] The photodiode receiving component in the embodiments of this application includes a beam splitting prism 210, a first condenser 220, a second condenser 230, a first photodiode chip 240, and a second photodiode chip 250; wherein, the beam splitting prism 210 is provided with an incident surface 213 and an exit surface opposite to each other, as well as a beam splitting surface 211 and a reflecting surface 212; the beam splitting surface 211 is disposed within the beam splitting prism 210, and is configured to transmit and reflect two optical signals with different wavelengths in the incident dual-wavelength mixed optical signal a respectively; the reflecting surface 212 is configured to change the transmission direction of the reflected optical signal reflected by the beam splitting surface 211, so that the reflected optical signal and the transmitted optical signal transmitted from the beam splitting surface 211 are parallel to each other and transmitted to the exit surface at a distance and output in parallel; the first condenser 220 and the second condenser 230 are respectively used to converge the output transmitted optical signal and reflected optical signal; the converged transmitted optical signal and reflected optical signal are respectively received by the first photodiode chip 240 and the second photodiode chip 250.

[0037] The above-mentioned reflected optical signal and the above-mentioned transmitted optical signal are parallel to each other and maintain a distance. Generally speaking, if the distance is small, the manufacturing cost of the beam splitting prism is high; if the distance is large, it affects the miniaturization of the component; in order to balance the manufacturing cost and ensure miniaturization, the distance in this embodiment is preferably 250um - 1500um.

[0038] In this application, the beam splitting prism 210 is used to split the incident dual-wavelength mixed optical signal a. Specifically, different wavelength optical signals are selectively reflected and transmitted to achieve the separation of different wavelength optical signals. Please refer to Figure 2 , the dual-wavelength mixed optical signal a includes two optical signals with wavelengths of λ1 and λ2. The beam splitting surface 211 of the beam splitting prism 210 is configured to transmit the optical signal with a wavelength of λ1 and reflect the optical signal with a wavelength of λ2, thereby separating the dual-wavelength mixed optical signal a into two optical signals: the first wavelength optical signal a1 and the second wavelength optical signal a2.

[0039] In the photodiode receiving component of this embodiment, the first condenser 220 and the first photodiode chip 240 are sequentially arranged on the transmission optical path of the transmitted optical signal output from the beam splitting prism 210. The transmitted optical signal passes through the first condenser 220 and the first photodiode chip 240 in sequence. The first condenser 220 is used to converge the transmitted optical signal, and the converged transmitted optical signal is received by the first photodiode chip 240.

[0040] In the photodiode receiving component of this embodiment, a second condenser element 230 and a second photodiode chip 250 are sequentially arranged on the transmission optical path of the reflected optical signal output from the beam splitting prism 210. The reflected optical signal sequentially passes through the second condenser element 230 and the second photodiode chip 250. The second condenser element 230 is used to converge the reflected optical signal, and the converged reflected optical signal is received by the second photodiode chip 250.

[0041] The transmitted optical signal is Figure 2 the first wavelength optical signal a1 in Figure 2 and the reflected optical signal is the second wavelength optical signal a2 in

[0042] In this embodiment, the photodiode receiving component further includes a base 260, and the first photodiode chip 240 and the second photodiode chip 250 are mounted on the base 260.

[0043] In this embodiment, the beam splitting surface 211 realizes the selective reflection and transmission of optical signals with different wavelengths through a beam splitting film. The beam splitting film is a common optical thin film. Common beam splitting film materials include metal materials such as aluminum, silver, and gold, and dielectric materials such as silicon dioxide, titanium dioxide, and tantalum pentoxide. This application does not limit the beam splitting film material. By adjusting the composition, thickness, and / or structure of the beam splitting film, different beam splitting characteristics can be obtained. In this embodiment, by adjusting the composition, thickness, and / or structure of the beam splitting film, the beam splitting surface 211 is configured to transmit optical signals with wavelengths of 1260 nm - 1280 nm and reflect optical signals with wavelengths of 1295 nm - 1330 nm.

[0044] In this embodiment, the reflection surface 212 realizes the reflection function through a reflection film. Common reflection film materials include metal materials such as aluminum, silver, and gold, and dielectric materials such as silicon dioxide, titanium dioxide, and tantalum pentoxide. By adjusting the composition, thickness, and / or structure of the reflection film, the reflection surface 212 is configured to reflect the second wavelength optical signal a2.

[0045] As a preferred solution of this embodiment, an antireflection film is provided on the incident surface 211. The antireflection film can reduce the reflection of the incident optical signal and increase the transmittance of the optical signal. Common antireflection film materials include tantalum pentoxide, silicon dioxide, titanium dioxide, etc.

[0046] As a preferred solution of this embodiment, the exit surface is parallel to the incident surface 211, and the exit surface further includes a first band-pass filtering surface 214 and a second band-pass filtering surface 215. The band-pass filtering surface is used to allow only optical signals with specific wavelengths to pass through while blocking optical signals with other wavelengths.

[0047] Further, the first band-pass filtering surface 214 and the second band-pass filtering surface 215 are respectively arranged in the emission regions of the transmitted optical signal and the reflected optical signal on the emission surface. The first band-pass filtering surface 214 is configured to only allow the transmitted optical signal to pass through, and the second band-pass filtering surface 215 is configured to only allow the reflected optical signal to pass through. The first band-pass filtering surface 214 and the second band-pass filtering surface 215 can be used to avoid crosstalk between the two emitted optical signals.

[0048] The first band-pass filtering surface 214 and the second band-pass filtering surface 215 can achieve the selective filtering function through a filtering film. Common filtering film materials include silicon dioxide, titanium dioxide, tantalum pentoxide, etc.

[0049] To ensure the parallelism of the output transmitted optical signal and reflected optical signal and facilitate the precise control of the distance between the output transmitted optical signal and reflected optical signal, a preferred structure of the beam splitting prism is also provided in this embodiment.

[0050] Please refer to Figure 4 , the beam splitting prism 210 is composed of a straight parallelepiped prism 210a and a right triangular prism 210b. The straight parallelepiped includes three pairs of opposite faces. In each pair of opposite faces, the two opposite faces are parallel and equal. One pair of opposite faces is a parallelogram, and the other two pairs of opposite faces are rectangles. Specifically, a rectangular face of the straight parallelepiped prism 210a is glued to the inclined surface of the right triangular prism 210b to form the beam splitting prism 210, and the glued surface is made into a beam splitting surface 211, that is, a beam splitting film is made on the glued surface to obtain the beam splitting surface 211.

[0051] In this preferred structure of the beam splitting prism, a surface of the straight parallelepiped prism 210a that is connected to the beam splitting surface 211 and faces the beam splitting surface 211 is used as the incident surface 213, the opposite surface of the incident surface 213 is used as the second band-pass filtering surface 215, and the opposite surface of the beam splitting surface 211 in the straight parallelepiped prism 210a is used as the reflection surface 212.

[0052] When designing the size and angle of the straight parallelepiped prism 210a, it should be ensured that: after the dual-wavelength mixed optical signal a is incident perpendicularly to the incident surface 213, it should be transmitted to the beam splitting surface 211. The second-wavelength optical signal a2 in the dual-wavelength mixed optical signal a should be reflected by the beam splitting surface 211 and reach the reflection surface 212, and then be reflected by the reflection surface 212 and output from the second band-pass filtering surface 215.

[0053] The straight parallelepiped prism 210a is used to horizontally shift the second-wavelength optical signal a2 in the incident dual-wavelength mixed optical signal a without changing its direction. Here, not changing its direction means that the incident and outgoing directions of the second-wavelength optical signal a2 are parallel.

[0054] In this preferred structure of the beam splitting prism, the surface of the right-angled triangular prism 210b opposite to the incident surface 213 is used as the output surface, that is, the first band-pass filtering surface 214. The dual-wavelength mixed optical signal a is incident from the incident surface 213 and transmitted to the beam splitting surface 211. The optical signal a1 with the first wavelength in the dual-wavelength mixed optical signal a is transmitted through the beam splitting surface 211, transmitted to the first band-pass filtering surface 214 and output from the first band-pass filtering surface 214.

[0055] Furthermore, the acute angle of the right-angled surface of the right-angled triangular prism 210b is equal to the acute angle of the parallelogram surface of the straight parallelepiped prism 210a. In a specific embodiment, the right-angled triangular prism 210b is preferably an isosceles right-angled triangular prism, that is, the two acute angles of its right-angled surface are 45 degrees; and the acute interior angle of the parallelogram surface of the straight parallelepiped prism 210a is preferably 45 degrees. The right-angled surface of the right-angled triangular prism 210b refers to the right-angled triangle surface.

[0056] Please refer to Figure 4-5 , which shows a schematic structural diagram of the photodiode receiving device in the embodiment of the present application. It includes a substrate 300, a bracket 400, a photodiode receiving component and a current-voltage conversion unit; the photodiode receiving component further includes a beam splitting prism 210, a first condenser 220, a second condenser 230, a first photodiode chip 240 and a second photodiode chip 250; the first photodiode chip 240, the second photodiode chip 250 and the current-voltage conversion unit are arranged on the substrate 300, and the current-voltage conversion unit is electrically connected to the first photodiode chip 240 and the second photodiode chip 250 to convert the photocurrent output by the first photodiode chip 240 and the second photodiode chip 250 into a voltage signal; the beam splitting prism 210, the first condenser 220 and the second condenser 230 are connected to the bracket 400, the bracket 400 is connected to the substrate 300, and the beam splitting prism 210, the first condenser 220, the second condenser 230, the first photodiode chip 240 and the second photodiode chip 250 should satisfy the positional relationship: the transmitted optical signal output from the beam splitting prism 210 should sequentially pass through the first condenser 220 and the first photodiode chip 240, and the reflected optical signal output from the beam splitting prism 210 should sequentially pass through the second condenser 230 and the second photodiode chip 250.

[0057] In this embodiment, there are two current-voltage conversion units, which are respectively denoted as the first current-voltage conversion unit 510 and the second current-voltage conversion unit 520, and are respectively electrically connected to the first photodiode chip 240 and the second photodiode chip 250 to respectively convert the optical signals output by the first photodiode chip 240 and the second photodiode chip 250 into voltage signals. The current-voltage conversion unit can be a transimpedance amplifier.

[0058] In this embodiment, the bracket 400 is in a circular ring shape, and the beam splitting prism 210, the first condenser element 220, and the second condenser element 230 are connected inside the bracket 400. In a specific implementation, the first condenser element 220, the second condenser element 230, and the bracket 400 are integrally formed. A connecting member 410 is provided at the bottom end of the circular ring-shaped bracket 400, and the bracket 400 is connected to the substrate 300 by gluing the connecting member 410 to the substrate 300.

[0059] The connection positions of the beam splitting prism 210, the first condenser element 220, and the second condenser element 230 on the bracket 400 and the connection position of the bracket 400 to the substrate 300 are designed in advance, and it should be ensured that: the first condenser element 220 and the first photodiode chip 240 are sequentially located on the transmission optical path of the transmitted optical signal output from the beam splitting prism 210; and the second condenser element 230 and the second photodiode chip 250 are sequentially located on the transmission optical path of the reflected optical signal output from the beam splitting prism 210.

[0060] In this embodiment, the material of the substrate 300 is selected as a valve alloy plated with gold; a plurality of wire bonding posts 310 are arranged on the substrate 300, and the wire bonding posts 310 are connected to the current-voltage conversion unit through gold wires 311, and the voltage signal generated by the conversion of the current-voltage conversion unit is output through the gold wires 311; a plurality of filter capacitors 320 are also installed on the substrate 300 to filter out interference signals.

[0061] The working principle of the photodiode receiving device in the embodiment of the present application is as follows:

[0062] The dual-wavelength mixed optical signal a enters the beam splitting prism 210 from the incident surface 213 and is transmitted to the beam splitting surface 211. The first-wavelength optical signal a1 and the second-wavelength optical signal a2 in the dual-wavelength mixed optical signal a are respectively transmitted and reflected by the beam splitting surface 211; the first-wavelength optical signal a1 passes through the beam splitting surface 211 and is output from the first selection filter surface 214; the second-wavelength optical signal a2 is reflected to the reflection surface 212, and the reflection surface 212 uses reflection to change the transmission direction of the second-wavelength optical signal a2 to be parallel to the first-wavelength optical signal a1 and is output from the second selection filter surface 215. The output first-wavelength optical signal a1 and second-wavelength optical signal a2 are transmitted parallel to each other and maintain a spacing, and after being converged by the first condenser element 220 and the second condenser element 230 respectively, they are received by the first photodiode chip 240 and the second photodiode chip 250.

[0063] After the first photodiode chip 240 and the second photodiode chip 250 receive an optical signal, a photocurrent is generated based on the photoelectric effect and output. Specifically, the photocurrents of the first photodiode chip 240 and the second photodiode chip 250 are respectively output to a first transimpedance amplifier 510 and a second transimpedance amplifier 520. The first transimpedance amplifier 510 and the second transimpedance amplifier 520 convert the photocurrent into a voltage signal, and then output it from a gold wire 311 through a bonding post 310. By processing the output voltage signal, the recognition of different optical signals can be realized.

[0064] If the prior art is used to prepare the photodiode receiving device of this embodiment for separating and receiving the dual-wavelength mixed optical signal a, two TO-46 chips plus external beam splitting and focusing optical components are required. However, the photodiode receiving device of the present application integrates the functions of beam splitting, focusing, and receiving, and does not require external beam splitting and focusing optical components. Only one TO-46 chip is needed to realize the separation and reception of the dual-wavelength mixed optical signal a, achieving miniaturization.

[0065] Those skilled in the art will understand that the present application is not limited to the specific embodiments here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments only. Without departing from the concept of the present application, more other equivalent embodiments can be included, all of which fall within the protection scope of the present application.

Claims

1. A photodiode receiving device for receiving dual-wavelength optical signals, characterized in that: It includes a substrate, a bracket, a photodiode receiving component and a current-voltage conversion unit; wherein the photodiode receiving component further includes a beam splitter prism, a first focusing element, a second focusing element, a first photodiode chip and a second photodiode chip; The beam splitter prism is provided with an incident surface and an exit surface opposite to each other, a beam splitter surface, and a reflection surface; the beam splitter surface is provided in the beam splitter prism, and is configured to transmit and reflect two optical signals in a dual-wavelength mixed optical signal incident from the incident surface respectively; the reflection surface is configured to change the transmission direction of the reflected optical signal reflected by the beam splitter surface, so that the reflected optical signal and the transmitted optical signal transmitted from the beam splitter surface are transmitted to the exit surface in parallel with each other and with a spacing maintained, and are output in parallel; The first photodiode chip, the second photodiode chip, and the current-voltage conversion unit are arranged on the substrate, and the current-voltage conversion unit is electrically connected to the first photodiode chip and the second photodiode chip to convert the photocurrent output by the first photodiode chip and the second photodiode chip into a voltage signal; The beam splitter prism, the first light focusing element, and the second light focusing element are connected to the bracket, the bracket is connected to the substrate, and the beam splitter prism, the first light focusing element, the second light focusing element, the first photodiode chip, and the second photodiode chip should satisfy the positional relationship: the transmitted light signal output from the beam splitter prism should pass through the first light focusing element and the first photodiode chip in sequence, and the reflected light signal output from the beam splitter prism should pass through the second light focusing element and the second photodiode chip in sequence.

2. The photodiode receiving device according to claim 1, characterized in that: There are two current-voltage conversion units, which are respectively denoted as a first current-voltage conversion unit and a second current-voltage conversion unit. The first current-voltage conversion unit is electrically connected to the first photodiode chip, and the second current-voltage conversion unit is electrically connected to the second photodiode chip.

3. The photodiode receiving device according to claim 1, characterized in that: The current-to-voltage conversion unit selects a transimpedance amplifier.

4. The photodiode receiving device according to claim 1, characterized in that: The exit surface includes a first selective filtering surface and a second selective filtering surface, which are respectively arranged on the exit areas of the transmitted light signal and the reflected light signal on the exit surface, the first selective filtering surface is configured to only allow the transmitted light signal to pass through, and the second selective filtering surface is configured to only allow the reflected light signal to pass through.

5. The photodiode receiving device according to claim 1, characterized in that: The spacing is 250um-1500um.

6. The photodiode receiving device according to claim 1, characterized in that: The beam splitter prism is composed of a straight parallelepiped prism and a right-angle prism; specifically: A rectangular surface of a right parallelepiped prism is glued to the inclined surface of a right-angle prism to form a beam splitter prism, and the glued surface is made into a beam splitter surface; a surface of the right parallelepiped prism connected to the beam splitter surface and facing the beam splitter surface is an incident surface, a surface opposite to the incident surface of the right parallelepiped prism is used as an exit surface of a reflected light signal, a surface opposite to the beam splitter surface of the right parallelepiped prism is used as a reflection surface, and a surface of the right-angle prism opposite to the incident surface is used as an exit surface of a transmitted light signal.

7. The photodiode receiving device according to claim 6, characterized in that: The step of making the bonding surface into a light splitting surface comprises: making a light splitting film on the bonding surface.

8. The photodiode receiving device according to claim 6, characterized in that: The exit surface in the straight parallelepiped prism is configured to allow only reflected light signals to pass therethrough.

9. The photodiode receiving device according to claim 6, characterized in that: The exit surface of the right-angle prism is configured to allow only the transmission light signal to pass through.

10. The photodiode receiving device according to claim 6, characterized in that: An anti-reflection film is arranged on the incident surface.

11. The photodiode receiving device according to claim 6, characterized in that: A reflective film is provided on the reflective surface.

12. The photodiode receiving device according to claim 6, characterized in that: The acute angles of the right-angled faces of the right-angled prism are equal to the acute angles of the parallelogram faces of the right parallelepiped prism.

13. The photodiode receiving device according to claim 6, characterized in that: The right-angle prism is an isosceles right-angle prism, and the interior angle of the parallelogram face of the right parallelepiped prism is 45 degrees.

14. Use of the photodiode receiving device according to any one of claims 1 to 13 in separating mixed optical signals.

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