Photodiode receiving device for receiving dual-wavelength optical signal
By integrating a beam splitter prism and a focusing element into a photodiode receiver, the problem of large space occupation for optical signal splitting and focusing in existing technologies has been solved, and the miniaturization of laser receivers has been achieved.
Patent Information
- Application Number
- CN202520514869.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-21
AI Technical Summary
Existing laser receivers require external beam splitting and focusing when receiving multi-wavelength mixed optical signals, resulting in a large footprint and making it difficult to meet miniaturization requirements.
An integrated photodiode receiver is used, and a beam splitter is used to separate the dual-wavelength mixed optical signal into two wavelength optical signals. The two signals are then focused by a focusing element and received by the photodiode chip. This integrates the functions of beam splitting, focusing and receiving, reducing the use of external optical components.
Integrated processing of optical signals was achieved, reducing the size of the laser receiver and meeting the miniaturization requirements.
Smart Images
Figure CN223943096U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical communication technology, specifically to a photodiode receiver for receiving dual-wavelength optical signals. Background Technology
[0002] When a laser receiver receives a multi-wavelength mixed optical signal, the light should first be split externally before each signal is received by a separate laser receiver. Currently, most light splitting uses filters; the splitting principle can be found in [link to relevant documentation]. Figure 1 A dual-wavelength mixed optical signal 'a' is incident on a first filter 110. The first wavelength optical signal 'a1' in the dual-wavelength mixed optical signal 'a' is transmitted through the first filter 110, while 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 a first condenser lens 140; the second wavelength optical signal 'a2' is reflected to a reflector 130, then reflected again by the reflector 130 to a second filter 120, and transmitted through the second filter 120 to a second condenser lens 150. The first condenser lens 140 is used to focus the first wavelength optical signal 'a1', and the second condenser lens 150 is used to focus the second wavelength optical signal 'a2'. The focused first wavelength optical signal 'a1' and second wavelength optical signal 'a2' are then received by independent laser receivers.
[0003] The above-mentioned existing technologies are currently widely used, but they have the problem of large space occupation, making it difficult to meet the current miniaturization requirements. Utility Model Content
[0004] The purpose of this application is to provide a photodiode receiver for receiving dual-wavelength optical signals. The photodiode receiver of this application integrates the functions of optical signal splitting, focusing and receiving, and can meet the requirements of miniaturization.
[0005] This application provides a photodiode receiving device for receiving dual-wavelength optical signals, including a substrate, a support, a photodiode receiving assembly, and a current-to-voltage conversion unit; wherein, the photodiode receiving assembly further includes a beam splitter, a first focusing element, a second focusing element, a first photodiode chip, and a second photodiode chip; the beam splitter is used to split the two wavelength optical signals in the incident dual-wavelength mixed optical signal, and to output the two wavelength optical signals parallel to each other and maintaining a distance between them;
[0006] The first photodiode chip, the second photodiode chip, and the current-to-voltage conversion unit are disposed on the substrate, and the current-to-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.
[0007] The beam splitter, the first focusing element, and the second focusing element are connected to the bracket, which is connected to the substrate. The beam splitter, the first focusing element, the second focusing element, the first photodiode chip, and the second photodiode chip should meet the following positional relationship: a wavelength light signal output from the beam splitter should pass through the first focusing element and the first photodiode chip in sequence, and another wavelength light signal output from the beam splitter should pass through the second focusing element and the second photodiode chip in sequence.
[0008] In some specific embodiments, there are two current-to-voltage conversion units, referred to as the first current-to-voltage conversion unit and the second current-to-voltage conversion unit, respectively. The first current-to-voltage conversion unit is electrically connected to the first photodiode chip, and the second current-to-voltage conversion unit is electrically connected to the second photodiode chip.
[0009] In some specific implementations, the current-to-voltage conversion unit is selected as a transimpedance amplifier.
[0010] In some specific embodiments, the support is circular, and the beam splitter, the first focusing element, and the second focusing element are connected inside the support.
[0011] Furthermore, the first and second focusing elements are integrally formed with the support.
[0012] In some specific embodiments, the beam splitter has opposing incident and exit surfaces, as well as a beam splitting surface and a reflecting surface. The beam splitting surface is disposed within the beam splitter and is configured to transmit and reflect the two optical signals in the dual-wavelength mixed optical signal incident from the incident surface, respectively. The reflecting 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 transmitted to the exit surface parallel to each other and at a distance, and are output in parallel.
[0013] Furthermore, the emission surface includes a first selective filtering surface and a second selective filtering surface, which are respectively disposed on the emission areas of the transmitted light signal and the reflected light signal on the emission surface. The first selective filtering surface is configured to allow only the transmitted light signal to pass through, and the second selective filtering surface is configured to allow only the reflected light signal to pass through.
[0014] Furthermore, the spacing is 250um-1500um.
[0015] Furthermore, the beam-splitting prism is composed of a right parallelepiped prism and a right-angled triangular prism; specifically:
[0016] A beam splitter is constructed by gluing a rectangular face of a right parallelepiped prism to the inclined face of a right-angled triangular prism, with the glued face serving as the beam splitting surface. The face of the right parallelepiped prism that is connected to and faces the beam splitting surface is the incident surface. The face opposite the incident surface of the right parallelepiped prism serves as the exit surface for reflected light signals. The face opposite the beam splitting surface of the right parallelepiped prism serves as the reflecting surface. The face of the right-angled triangular prism that faces the incident surface serves as the exit surface for transmitted light signals.
[0017] Furthermore, the exit surface of the right parallelepiped prism is configured to allow only reflected light signals to pass through.
[0018] Furthermore, the exit surface of the right-angle prism is configured to allow only transmitted light signals to pass through.
[0019] Furthermore, the acute angle of the right-angled face of the right-angled prism is equal to the acute angle of the parallelogram face of the right parallelepiped prism. Preferably, the right-angled prism is an isosceles right-angled prism, and the interior angle of the parallelogram face of the right parallelepiped prism is 45 degrees.
[0020] Please see Figure 2 The diagram shown is a schematic representation of the beam-splitting principle of the photodiode receiving device of this application. Figure 1 Unlike the principle of using filters for beam splitting, this application uses a beam splitter prism 210 for beam splitting. The beam splitting surface 211 within the beam splitter prism 210 separates the dual-wavelength mixed optical signal a into a first-wavelength optical signal a1 and a second-wavelength optical signal a2. The reflecting surface 212 changes the transmission direction of the second-wavelength optical signal a2, making it output parallel to the first-wavelength optical signal a1. Figure 1 Compared to the previous version, the photodiode receiver in this application integrates the functions of optical signal splitting, focusing and receiving. Since there is no need to lay out optical components such as filters and reflectors, it can meet the requirements of miniaturization.
[0021] Compared with the prior art, the beneficial effects of this application are as follows:
[0022] Existing laser receivers lack optical signal splitting and focusing capabilities, requiring external optical components such as filters and reflectors to achieve these functions. This results in a large footprint and hinders miniaturization. The photodiode receiver in this application integrates optical signal splitting, focusing, and receiving functions. Furthermore, since it eliminates the need for external filters and reflectors, it can be miniaturized and meets TO packaging requirements. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is the current technology based on the principle of light dispersion using filters;
[0025] Figure 2 This is a schematic diagram illustrating the beam-splitting principle of the photodiode receiving device of this application;
[0026] Figure 3 This is a schematic diagram of the specific structure of the photodiode receiving component in the embodiments of this application;
[0027] Figure 4 This is a schematic diagram of the specific structure of the beam-splitting prism in the embodiments of this application;
[0028] Figure 5 This is a schematic diagram of the specific structure of the photodiode receiving device in the embodiments of this application;
[0029] Figure 6 This is a schematic diagram of the substrate layout in the photodiode receiver device in the embodiments of this application.
[0030] Reference numerals: First filter 110, second filter 120, reflector 130, first condenser lens 140, second condenser lens 150; beam splitter prism 210, right parallelepiped prism 210a, right-angle triangular prism 210b, beam splitting surface 211, reflecting surface 212, incident surface 213, first bandpass filter surface 214, second bandpass 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, connector 410; first current-to-voltage conversion unit 510, second current-to-voltage conversion unit 520; dual-wavelength mixed optical signal a, first wavelength optical signal a1, second wavelength optical signal a2. Detailed Implementation
[0031] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0032] The core component of the photodiode receiver device for dual-wavelength optical signal reception in this application is the photodiode receiver component. For ease of understanding, it will be described below in conjunction with... Figure 2-4 The specific structure and technical principle of the photodiode receiving component in the embodiments of this application are described in detail.
[0033] In this embodiment, the photodiode receiving component includes a beam splitter 210, a first focusing element 220, a second focusing element 230, a first photodiode chip 240, and a second photodiode chip 250. The beam splitter 210 has opposing incident and exit surfaces, a beam splitter 211, and a reflecting surface 212. The beam splitter 211 is disposed within the beam splitter 210 and is configured to transmit and reflect two different wavelengths of light signals in the incident dual-wavelength mixed light signal a, respectively. The reflecting surface 212 is configured to change the transmission direction of the reflected light signal reflected by the beam splitter 211, so that the reflected light signal and the transmitted light signal transmitted from the beam splitter 211 are transmitted parallel to each other and maintain a distance from each other to the exit surface and output in parallel. The first focusing element 220 and the second focusing element 230 are used to converge the output transmitted and reflected light signals, respectively. The converged transmitted and reflected light signals are received by the first photodiode chip 240 and the second photodiode chip 250, respectively.
[0034] The reflected light signal and the transmitted light signal are parallel to each other and maintain a distance. Generally speaking, a small distance will result in a high manufacturing cost of the beam splitter; a large distance will affect the miniaturization of the component. In order to balance manufacturing cost and ensure miniaturization, the distance in this embodiment is preferably 250um-1500um.
[0035] In this application, a 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 separation of different wavelength optical signals. Please refer to [link to relevant documentation]. Figure 2 The dual-wavelength mixed optical signal a contains two optical signals with wavelengths of λ1 and λ2. The beam splitting surface 211 of the beam splitter 210 is configured to transmit the optical signal with wavelength λ1 and reflect the optical signal with wavelength 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.
[0036] In the photodiode receiving assembly of this embodiment, a first focusing element 220 and a first photodiode chip 240 are arranged sequentially on the transmission optical path of the transmitted light signal output from the beam splitter 210. The transmitted light signal passes through the first focusing element 220 and the first photodiode chip 240 in sequence. The first focusing element 220 is used to focus the transmitted light signal, and the focused transmitted light signal is received by the first photodiode chip 240.
[0037] In the photodiode receiving assembly of this embodiment, a second focusing element 230 and a second photodiode chip 250 are arranged sequentially on the transmission optical path of the reflected light signal output from the beam splitter 210. The reflected light signal passes through the second focusing element 230 and the second photodiode chip 250 in sequence. The second focusing element 230 is used to focus the reflected light signal, and the focused reflected light signal is received by the second photodiode chip 250.
[0038] Transmitted light signal Figure 2 The first wavelength optical signal a1 in the light, the reflected light signal is... Figure 2 The second wavelength optical signal a2 in the signal.
[0039] In this embodiment, the photodiode receiving component further includes a base 260, on which the first photodiode chip 240 and the second photodiode chip 250 are mounted.
[0040] In this embodiment, the beam-splitting surface 211 achieves selective reflection and transmission of light signals of different wavelengths through a beam-splitting film. A beam-splitting film is a common optical thin film, and common beam-splitting film materials include metallic 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. Different beam-splitting characteristics can be obtained by adjusting the composition, thickness, and / or structure of the beam-splitting film. 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 light signals with wavelengths of 1260nm-1280nm and reflect light signals with wavelengths of 1295nm-1330nm.
[0041] In this embodiment, the reflective surface 212 achieves its reflective function through a reflective film. Common reflective film materials include metallic 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 reflective film, the reflective surface 212 is configured to reflect the second wavelength light signal a2.
[0042] As a preferred embodiment, an antireflection film is provided on the incident surface 211. The antireflection film can reduce the reflection of the incident light signal and increase the transmittance of the light signal. Common antireflection film materials include tantalum pentoxide, silicon dioxide, and titanium dioxide.
[0043] In a preferred embodiment, the exit surface is parallel to the incident surface 211, and the exit surface further includes a first bandpass filter surface 214 and a second bandpass filter surface 215. The bandpass filter surface is used to allow only optical signals of specific wavelengths to pass through, while blocking optical signals of other wavelengths.
[0044] Furthermore, the first bandpass filter surface 214 and the second bandpass filter surface 215 are respectively disposed in the emission regions of the transmitted light signal and the reflected light signal on the emission surface. The first bandpass filter surface 214 is configured to allow only the transmitted light signal to pass through, and the second bandpass filter surface 215 is configured to allow only the reflected light signal to pass through. Using the first bandpass filter surface 214 and the second bandpass filter surface 215 can prevent crosstalk between the two types of emitted light signals.
[0045] The first bandpass filter surface 214 and the second bandpass filter surface 215 can achieve selective filtering function through filter films. Common filter film materials include silicon dioxide, titanium dioxide, tantalum pentoxide, etc.
[0046] To ensure the parallelism of the output transmitted light signal and the reflected light signal, and to facilitate precise control of the spacing between the output transmitted light signal and the reflected light signal, this embodiment also provides a preferred structure for the beam splitter.
[0047] Please see Figure 4 The beam splitter 210 is composed of a right parallelepiped prism 210a and a right-angled triangular prism 210b. The right parallelepiped includes three pairs of opposite faces, and two of the opposite faces in each pair 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 right parallelepiped prism 210a is glued to the inclined face of the right-angled triangular prism 210b to form the beam splitter prism 210. The glued surface is made into a beam splitter 211, that is, a beam splitter film is made on the glued surface to obtain the beam splitter 211.
[0048] In this preferred structure of the beam splitter prism, the side of the right parallelepiped prism 210a that is connected to and faces the beam splitter 211 is used as the incident surface 213, the opposite side of the incident surface 213 is used as the second bandpass filter surface 215, and the opposite side of the beam splitter 211 in the right parallelepiped prism 210a is used as the reflecting surface 212.
[0049] When designing the dimensions and angles of the right parallelepiped prism 210a, it should be ensured that: the dual-wavelength mixed light signal a is transmitted to the beam splitter 211 after being incident perpendicularly to the incident surface 213; the second wavelength light signal a2 in the dual-wavelength mixed light signal a is reflected by the beam splitter 211 and reaches the reflecting surface 212; and after being reflected by the reflecting surface 212, it is output from the second bandpass filter surface 215.
[0050] The straight parallelepiped prism 210a is used to horizontally deflect the second wavelength light signal a2 in the incident dual-wavelength mixed light signal a without changing its direction. Here, "without changing its direction" means that the incident and outgoing directions of the second wavelength light signal a2 are parallel.
[0051] In this preferred structure of the beam splitter, the side of the right-angle triangular prism 210b opposite to the incident surface 213 is used as the exit surface, namely the first bandpass filter surface 214. The dual-wavelength mixed optical signal a is incident from the incident surface 213 and transmitted to the beam splitter 211. The first wavelength optical signal a1 in the dual-wavelength mixed optical signal a is transmitted from the beam splitter 211 and transmitted to the first bandpass filter surface 214 and output from the first bandpass filter surface 214.
[0052] Furthermore, the acute angle of the right-angled facet of the right-angled prism 210b is equal to the acute angle of the parallelogram facet of the right parallelepiped prism 210a. In one specific embodiment, the right-angled prism 210b is preferably an isosceles right-angled prism, that is, the two acute angles of its right-angled facet are 45 degrees; and the acute interior angle of the parallelogram facet of the right parallelepiped prism 210a is preferably 45 degrees. The right-angled facet of the right-angled prism 210b refers to a right-angled triangular facet.
[0053] Please see Figure 4-5 The diagram shows a schematic of the structure of a photodiode receiving device in an embodiment of this application. It includes a substrate 300, a support 400, a photodiode receiving assembly, and a current-to-voltage conversion unit. The photodiode receiving assembly further includes a beam splitter 210, a first focusing element 220, a second focusing element 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-to-voltage conversion unit are disposed on the substrate 300, and the current-to-voltage conversion unit is electrically connected to the first photodiode chip 240 and the second photodiode chip 250 to transmit the signal. The photocurrent output by the second photodiode chip 250 is converted into a voltage signal; the beam splitter 210, the first focusing element 220, and the second focusing element 230 are connected to the bracket 400, and the bracket 400 is connected to the substrate 300. The beam splitter 210, the first focusing element 220, the second focusing element 230, the first photodiode chip 240, and the second photodiode chip 250 should meet the following positional relationship: the transmitted light signal output from the beam splitter 210 should pass through the first focusing element 220 and the first photodiode chip 240 in sequence, and the reflected light signal output from the beam splitter 210 should pass through the second focusing element 230 and the second photodiode chip 250 in sequence.
[0054] In this embodiment, there are two current-to-voltage conversion units, designated as the first current-to-voltage conversion unit 510 and the second current-to-voltage conversion unit 520, respectively. These units are electrically connected to the first photodiode chip 240 and the second photodiode chip 250, respectively, and are used to convert the optical signals output by the first photodiode chip 240 and the second photodiode chip 250 into voltage signals. The current-to-voltage conversion unit can be a transimpedance amplifier.
[0055] In this embodiment, the support 400 is annular, and the beam splitter 210, the first focusing element 220, and the second focusing element 230 are connected within the support 400. In one specific embodiment, the first focusing element 220, the second focusing element 230, and the support 400 are integrally formed. A connector 410 is provided at the annular bottom end of the support 400, and the support 400 is connected to the substrate 300 by adhesive bonding the connector 410 to the substrate 300.
[0056] The connection positions of the beam splitter 210, the first focusing element 220, and the second focusing element 230 on the support 400, as well as the connection position between the support 400 and the substrate 300, should be designed in advance to ensure that: the first focusing element 220 and the first photodiode chip 240 are sequentially located on the transmission optical path of the transmitted light signal output from the beam splitter 210; and the second focusing element 230 and the second photodiode chip 250 are sequentially located on the transmission optical path of the reflected light signal output from the beam splitter 210.
[0057] In this embodiment, the substrate 300 is made of a valve alloy plated with gold; several wire bonding posts 310 are arranged on the substrate 300, and the wire bonding posts 310 are connected to the current-to-voltage conversion unit through gold wires 311. The voltage signal generated by the current-to-voltage conversion unit is output through the gold wires 311; several filter capacitors 320 are also installed on the substrate 300 to filter interference signals.
[0058] The working principle of the photodiode receiver in this application embodiment is as follows:
[0059] A dual-wavelength hybrid optical signal 'a' enters the beam splitter 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 hybrid optical signal 'a' are transmitted and reflected by the beam splitting surface 211, respectively. The first wavelength optical signal 'a1' is transmitted through the beam splitting surface 211 and output from the first selective filter surface 214. The second wavelength optical signal 'a2' is reflected to the reflecting surface 212, which 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 outputs from the second selective 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 distance. After being converged by the first focusing element 220 and the second focusing element 230, respectively, they are received by the first photodiode chip 240 and the second photodiode chip 250.
[0060] After receiving the optical signal, the first photodiode chip 240 and the second photodiode chip 250 generate and output photocurrent based on the photoelectric effect. Specifically, the photocurrents from the first photodiode chip 240 and the second photodiode chip 250 are output to the first transimpedance amplifier 510 and the second transimpedance amplifier 520, respectively. The first transimpedance amplifier 510 and the second transimpedance amplifier 520 convert the photocurrent into a voltage signal, which is then output from the gold wire 311 via the wire bonding post 310. By processing the output voltage signal, the identification of different optical signals can be achieved.
[0061] If the photodiode receiver of this embodiment is fabricated using existing technology to separate and receive the dual-wavelength mixed optical signal 'a', two TO-46 chips plus external beam-splitting and focusing optical components are required. However, the photodiode receiver of this application integrates beam-splitting, focusing, and receiving functions, eliminating the need for external beam-splitting and focusing optical components. Only a single TO-46 chip is needed to achieve the separation and reception of the dual-wavelength mixed optical signal 'a', thus realizing miniaturization.
[0062] Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of this application, all of which fall within the scope of protection of this application.
Claims
1. A photodiode receiving device for receiving dual-wavelength optical signals, characterized in that: It includes a substrate, a support, a photodiode receiving component, and a current-to-voltage conversion unit; wherein the photodiode receiving component further includes a beam splitter, a first focusing element, a second focusing element, a first photodiode chip, and a second photodiode chip; A beam splitter is used to separate the two wavelengths of an incident dual-wavelength mixed optical signal and output the two wavelengths of optical signal parallel to each other and with a distance between them. The first photodiode chip, the second photodiode chip, and the current-to-voltage conversion unit are disposed on the substrate, and the current-to-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, the first focusing element, and the second focusing element are connected to the bracket, which is connected to the substrate. The beam splitter, the first focusing element, the second focusing element, the first photodiode chip, and the second photodiode chip should meet the following positional relationship: a wavelength light signal output from the beam splitter should pass through the first focusing element and the first photodiode chip in sequence, and another wavelength light signal output from the beam splitter should pass through the second focusing element and the second photodiode chip in sequence.
2. The photodiode receiving device as described in claim 1, characterized in that: There are two current-to-voltage conversion units, referred to as the first current-to-voltage conversion unit and the second current-to-voltage conversion unit, respectively. The first current-to-voltage conversion unit is electrically connected to the first photodiode chip, and the second current-to-voltage conversion unit is electrically connected to the second photodiode chip.
3. The photodiode receiving device as described in claim 1, characterized in that: The current-to-voltage conversion unit is selected as a transimpedance amplifier.
4. The photodiode receiving device as described in claim 1, characterized in that: The bracket is circular, and the beam splitter, the first focusing element, and the second focusing element are connected inside the bracket.
5. The photodiode receiving device as described in claim 4, characterized in that: The first and second focusing elements are integrally formed with the support.
6. The photodiode receiving device as described in claim 1, characterized in that: The beam splitter has opposing incident and exit surfaces, as well as a beam splitting surface and a reflecting surface. The beam splitting surface is disposed inside the beam splitter and is configured to transmit and reflect the two optical signals in the dual-wavelength mixed optical signal incident from the incident surface, respectively. The reflecting 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 transmitted to the exit surface in parallel and at a distance from each other and are output in parallel.
7. The photodiode receiving device as described in claim 6, characterized in that: The emission surface includes a first selective filter surface and a second selective filter surface, which are respectively disposed on the emission areas of the transmitted light signal and the reflected light signal on the emission surface. The first selective filter surface is configured to allow only the transmitted light signal to pass through, and the second selective filter surface is configured to allow only the reflected light signal to pass through.
8. The photodiode receiving device as described in claim 6, characterized in that: The spacing is 250um-1500um.
9. The photodiode receiving device as described in claim 6, characterized in that: The beam-splitting prism is composed of a right parallelepiped prism and a right-angled triangular prism; specifically: A beam splitter is constructed by gluing a rectangular face of a right parallelepiped prism to the inclined face of a right-angled triangular prism, with the glued face serving as the beam splitting surface. The face of the right parallelepiped prism that is connected to and faces the beam splitting surface is the incident surface. The face opposite the incident surface of the right parallelepiped prism serves as the exit surface for reflected light signals. The face opposite the beam splitting surface of the right parallelepiped prism serves as the reflecting surface. The face of the right-angled triangular prism that faces the incident surface serves as the exit surface for transmitted light signals.
10. The photodiode receiving device as described in claim 9, characterized in that: The exit surface of the right parallelepiped prism is configured to allow only reflected light signals to pass through.
11. The photodiode receiving device as described in claim 9, characterized in that: The exit surface of the right-angle prism is configured to allow only transmitted light signals to pass through.
12. The photodiode receiving device as described in claim 6, characterized in that: An anti-reflection coating is provided on the incident surface.
13. The photodiode receiving device as described in claim 9, characterized in that: The acute angle of the right-angled face of the right-angled triangular prism is equal to the acute angle of the parallelogram face of the right parallelepiped prism.
14. The photodiode receiving device as described in claim 9, 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.