Photodiode receiving assembly with light splitting function and application thereof

Abstract

The invention discloses a photodiode receiving assembly with a light splitting function and application thereof. The photodiode receiving assembly comprises a light splitting prism, a first light condensing element, a second light condensing element, a first photodiode chip and a second photodiode chip, the beam splitter prism is provided with an incident surface, an emergent surface, a beam splitting surface and a reflecting surface, the light splitting surface is configured to respectively transmit and reflect two optical signals with different wavelengths in the dual-wavelength mixed optical signals; the reflecting surface is configured to be used for changing the transmission direction of a reflected light signal, so that the reflected light signal and a transmission light signal transmitted from the light splitting surface are parallel to each other and are transmitted to the emergent surface in a spaced manner to be output; the output transmission light signal sequentially passes through the first light condensing element and the first photodiode chip; and the output reflected light signal sequentially passes through the second light condensing element and the second photodiode chip. The receiving assembly integrates the light splitting, converging and receiving functions of optical signals, miniaturization can be achieved, and the TO packaging requirement is met.

Description

Technical Field

[0001] This application relates to the field of optical communication technologies, and particularly to a photodiode receiving component with a beam splitting function and its application. Background Art

[0002] When a laser receiver receives a multi-wavelength mixed optical signal, beam splitting should be first performed outside the laser receiver, and then independent laser receivers are used to separately receive the separated optical signals. Currently, beam splitting mostly uses 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 is transmitted 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 is transmitted 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 prior art 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 this application is to provide a photodiode receiving component with a beam splitting function and its application. The photodiode receiving component of this application integrates the functions of beam splitting, converging, and receiving of optical signals, and can meet the miniaturization requirements.

[0005] On the one hand, this application provides a photodiode receiving component with a beam splitting function, including a beam splitting prism, a first condensing element, a second condensing 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 reflecting surface; the beam splitting surface is disposed inside the beam splitting prism and is configured to respectively transmit and reflect two optical signals with different wavelengths in the incident dual-wavelength mixed optical signal; 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 through the beam splitting surface are transmitted to the exit surface in parallel and at a distance from each other and are output in parallel;

[0007] The first condenser element and the first photodiode chip are arranged in sequence along the transmission optical path of the transmitted optical signal output; the second condenser element and the second photodiode chip are arranged in sequence along the transmission optical path of the reflected optical signal output.

[0008] In some specific embodiments, the exit surface includes a first band-pass filtering surface and a second band-pass filtering surface. The first band-pass filtering surface and the second band-pass filtering surface are respectively disposed in the exit regions of the transmitted optical signal and the reflected optical signal on the exit surface. The first band-pass filtering surface is configured to allow only the transmitted optical signal to pass through, and the second band-pass filtering surface is configured to allow only the reflected optical signal to pass through.

[0009] In some specific embodiments, an anti-reflection film is provided on the incident surface.

[0010] In some specific embodiments, a beam-splitting film is provided on the beam-splitting surface.

[0011] In some specific embodiments, a reflective film is provided on the reflection surface.

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

[0013] In some specific embodiments, the photodiode receiving assembly further includes a base, and the first photodiode chip and the second photodiode chip are mounted on the base.

[0014] In some specific embodiments, the beam-splitting prism is composed of a straight parallelepiped prism and a right triangular prism; specifically: a rectangular surface of the straight parallelepiped prism is glued to the inclined surface of the right triangular prism to form the beam-splitting prism, and the glued surface is made into the beam-splitting surface; in the straight parallelepiped prism, the surface connected to 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 optical signal, the opposite surface of the beam-splitting surface in the straight parallelepiped prism is used as the reflection surface, and the surface opposite to the incident surface in the right triangular prism is used as the exit surface of the transmitted optical signal.

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

[0016] Further, the exit surface of the reflected optical signal is configured to allow only the reflected optical signal to pass through.

[0017] Further, the exit surface of the transmitted optical signal is configured to allow only the transmitted optical signal to pass through.

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

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

[0020] Further, the right-angled triangular prism is an isosceles right-angled triangular prism, and the acute interior angle of the parallelogram face of the straight parallelepiped prism is 45 degrees.

[0021] Still further, the right-angled triangular prism is preferably an isosceles right-angled triangular prism, and the acute interior angle of the parallelogram face of the straight parallelepiped prism is preferably 45 degrees.

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

[0023] Please refer to Figure 2 , which shows a schematic diagram of the light splitting principle of the photodiode receiving component of the present application. Different from Figure 1 the principle of using a filter to split light in Figure 1 , the present application uses a beam splitting prism 210 for light splitting. 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

[0024] shown in

[0025] Compared with the prior art, the beneficial effects of the present application are as follows: Description of the Drawings

[0026] In order 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 following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

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

[0028] Figure 2 is a schematic diagram of the light splitting principle of the photodiode receiving component in the embodiment;

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

[0030] Figure 4 It is a schematic structural diagram of the beam splitting prism in the embodiment.

[0031] Reference numerals: first filter 110, second filter 120, reflector 130, first condenser lens 140, second condenser lens 150; beam splitting prism 210, straight parallelepiped prism 210a, right-angled triangular prism 210b, beam splitting surface 211, reflection surface 212, incident surface 213, first band-pass filtering surface 214, second band-pass filtering surface 215, first condenser element 220, second condenser element 230, first photodiode chip 240, second photodiode chip 250, base 260; dual-wavelength mixed optical signal a, first-wavelength optical signal a1, second-wavelength optical signal a2. Detailed implementation manners

[0032] Next, in combination with the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. 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 shall fall within the protection scope of the present application.

[0033] Next, in combination with Figures 2 - 4 The specific structure and its technical principle of the photodiode receiving component with beam splitting function in the embodiment of the present application will be described in detail.

[0034] The photodiode receiving component with beam splitting function in the embodiment of the present application includes a beam splitting prism 210, a first condenser element 220, a second condenser element 230, a first photodiode chip 240 and a second photodiode chip 250; wherein, the beam splitting prism 210 is provided with an opposite incident surface 213 and an exit surface, as well as a beam splitting surface 211 and a reflection surface 212; the beam splitting surface 211 is disposed inside 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 reflection 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 are transmitted to the exit surface at a distance and output in parallel; the first condenser element 220 and the second condenser element 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.

[0035] The above-mentioned reflected light signal and the above-mentioned transmitted light signal are parallel to each other and maintain a spacing. Generally speaking, if the spacing is small, the manufacturing cost of the beam splitting prism is high; if the spacing is large, it affects the miniaturization of the component. In order to balance the manufacturing cost and ensure miniaturization, the spacing in this embodiment is preferably 250um - 1500um.

[0036] In this application, the beam splitting prism 210 is used to split the incident dual-wavelength mixed light signal a. Specifically, different wavelength light signals are selectively reflected and transmitted to achieve the separation of different wavelength light signals. Please refer to Figure 2 , the dual-wavelength mixed light signal a includes two light signals with wavelengths of λ1 and λ2. The beam splitting surface 211 of the beam splitting prism 210 is configured to transmit the light signal with a wavelength of λ1 and reflect the light signal with a wavelength of λ2, thereby separating the dual-wavelength mixed light signal a into two light signals: the first wavelength light signal a1 and the second wavelength light signal a2.

[0037] In this embodiment, a first condenser element 220 and a first photodiode chip 240 are sequentially arranged on the transmission optical path of the transmitted light signal output from the beam splitting prism 210. The transmitted light signal passes through the first condenser element 220 and the first photodiode chip 240 in sequence. The first condenser element 220 is used to converge the transmitted light signal, and the converged transmitted light signal is received by the first photodiode chip 240.

[0038] In this embodiment, a second condenser element 230 and a second photodiode chip 250 are sequentially arranged on the transmission optical path of the reflected light signal output from the beam splitting prism 210. The reflected light signal passes through the second condenser element 230 and the second photodiode chip 250 in sequence. The second condenser element 230 is used to converge the reflected light signal, and the converged reflected light signal is received by the second photodiode chip 250.

[0039] In this embodiment, the transmitted light signal is the Figure 2 first wavelength light signal a1 in Figure 2 , and the reflected light signal is the

[0040] second wavelength light signal a2 in

[0041] In this embodiment, the beam splitting surface 211 realizes the selective reflection and transmission of optical signals of 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, gold, etc., and dielectric materials such as silicon dioxide, titanium dioxide, tantalum pentoxide, etc. This application places no restrictions on the beam splitting film materials. 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.

[0042] 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, gold, etc., and dielectric materials such as silicon dioxide, titanium dioxide, tantalum pentoxide, etc. 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.

[0043] 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.

[0044] 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 of specific wavelengths to pass through while blocking optical signals of other wavelengths.

[0045] Furthermore, the first band-pass filtering surface 214 and the second band-pass filtering surface 215 are respectively disposed in the exit regions of the transmitted optical signal and the reflected optical signal on the exit surface. The first band-pass filtering surface 214 is configured to allow only the transmitted optical signal to pass through, and the second band-pass filtering surface 215 is configured to allow only the reflected optical signal to pass through. The use of the first band-pass filtering surface 214 and the second band-pass filtering surface 215 can avoid crosstalk between the two exit optical signals.

[0046] The first band-pass filtering surface 214 and the second band-pass filtering surface 215 can realize the selective filtering function through a filtering film. Common filtering film materials include silicon dioxide, titanium dioxide, tantalum pentoxide, etc.

[0047] To ensure the parallelism of the output transmitted optical signal and reflected optical signal and facilitate the precise control of the spacing between the output transmitted optical signal and reflected optical signal, this embodiment provides a preferred structure of the beam splitting prism.

[0048] 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, where the two 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 straight parallelepiped prism 210a is glued to the inclined face 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.

[0049] In this preferred structure of the beam splitting prism, the 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.

[0050] When designing the size and angle of the straight parallelepiped prism 210a, it should be ensured that: the dual-wavelength mixed optical signal a is incident perpendicularly to the incident surface 213 and then transmitted to the beam splitting surface 211. The second-wavelength optical signal a2 in the dual-wavelength mixed optical signal a is reflected by the beam splitting surface 211 and should reach the reflection surface 212, and then be reflected by the reflection surface 212 and output from the second band-pass filtering surface 215.

[0051] The straight parallelepiped prism 210a is used to horizontally offset 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.

[0052] In this preferred structure of the beam splitting prism, the surface of the right triangular prism 210b that is opposite to the incident surface 213 is used as the outgoing 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 first-wavelength optical signal a1 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.

[0053] Furthermore, the acute angle of the right-angled face of the right triangular prism 210b is equal to the acute angle of the parallelogram face of the straight parallelepiped prism 210a. In a specific embodiment, the right triangular prism 210b is preferably an isosceles right triangular prism, that is, the two acute angles of its right-angled face are 45 degrees; and the acute interior angle of the parallelogram face of the straight parallelepiped prism 210a is preferably 45 degrees.

[0054] The right-angled face of the right triangular prism 210b refers to the right-angled triangular face.

[0055] The above photodiode receiving component with beam splitting function has the following working principle:

[0056] 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 selective filtering 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 selective filtering 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. 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. After the first photodiode chip 240 and the second photodiode chip 250 receive the optical signal, a photocurrent is generated based on the photoelectric effect and output, thereby realizing the separation of optical signals of different wavelengths.

[0057] If the prior art is used to realize the separation and reception of the dual-wavelength mixed optical signal a in this embodiment, two TO-46 chips plus external beam splitting and converging optical components are required. However, the photodiode receiving component of this application integrates the functions of beam splitting, converging, and receiving, and does not require external beam splitting and converging 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.

[0058] Those skilled in the art will understand that this 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 this application. Therefore, although this application has been described in more detail through the above embodiments, this application is not limited to the above embodiments only. Without departing from the concept of this application, more other equivalent embodiments can be included, all of which belong to the protection scope of this application.

Claims

1. A photodiode receiving component with a light splitting function, characterized in that: It includes a beam splitter prism, a first light focusing element, a second light 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 relative 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 of different wavelengths in the incident dual-wavelength mixed optical signal 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 light-concentrating element and the first photodiode chip are arranged in sequence along the transmission optical path of the output transmitted light signal; the second light-concentrating element and the second photodiode chip are arranged in sequence along the transmission optical path of the output reflected light signal.

2. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: The exit surface includes a first band-pass filter surface and a second band-pass filter 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 band-pass filter surface is configured to only allow the transmitted light signal to pass through, and the second band-pass filter surface is configured to only allow the reflected light signal to pass through.

3. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: An anti-reflection film is arranged on the incident surface.

4. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: The light splitting surface is provided with a light splitting film.

5. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: A reflective film is provided on the reflective surface.

6. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: The spacing is 250um-1500um.

7. The photodiode receiving component with light splitting function as claimed in claim 1, characterized in that: The photodiode receiving component also includes a base, and the first photodiode chip and the second photodiode chip are mounted on the base.

8. The photodiode receiving component with light splitting function as claimed in 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.

9. The photodiode receiving component with light splitting function as claimed in claim 8, 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.

10. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: The exit surface of the reflected light signal is configured to allow only the reflected light signal to pass through.

11. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: The emission surface of the transmitted light signal is configured to allow only the transmitted light signal to pass through.

12. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: An anti-reflection film is arranged on the incident surface.

13. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: A reflective film is provided on the reflective surface.

14. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: The acute angle of the right angle face of the right angle triangular prism is equal to the acute angle of the parallelogram face of the right parallelepiped prism.

15. The photodiode receiving component with light splitting function as claimed in claim 8, characterized in that: The right-angle prism is an isosceles right-angle prism, and the acute internal angle of the parallelogram face of the right parallelepiped prism is 45 degrees.

16. Use of the photodiode receiving assembly according to any one of claims 1 to 15 in separating mixed optical signals.

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