Wavelength division multiplexing device based on dichroscope for optical module and optical module

Abstract

The demultiplexing process of the wavelength division multiplexing device at the receiving end of the optical module comprises the following steps: transmitting a single beam of signal light containing four wavelengths lambda 1, lambda 2, lambda 3 and lambda 4 into the device through a Receptacle connector, collimating the single beam of signal light into a beam of parallel light through a C-Lens lens, and transmitting the parallel light to the receiving end of the optical module; and the light passes through the light path turning prism for preventing reflected light from being transmitted back to an input light path, enters the WDM module and is demultiplexed into four paths of parallel signal light with wavelengths of lambda 1, lambda 2, lambda 3 and lambda 4, is focused by the lens array, is received by the PD array, is converted into an electric signal from an optical signal, is amplified by the TIA 4CH, and is transmitted to the receiving end circuit RX Circuit. According to the utility model, the miniaturization of the wavelength division multiplexing device in the optical module can be promoted, and the manufacturing cost and the assembly difficulty of the high-speed optical module can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of optical communication especially relates to a kind of wave division multiplexing device and optical module based on dichroic mirror for optical module. BACKGROUND

[0002] The rapid development of AI large model, HPC, cloud computing and other services drives the rapid growth of computing power infrastructure, and the demand for high-speed optical modules such as 400G and 800G is also growing exponentially, directly driving the technical upgrade of optical modules to higher rates. Wave division multiplexer is an important scheme to improve the rate of optical modules. Currently, this scheme mainly uses AWG and Z-Block methods, which have fixed structure and cost, making it difficult to further reduce costs and space compression, and it is also difficult to disassemble and repair after being fixed in the optical module.

[0003] Among them, the Z-Block technology is based on thin film filters, which are attached to one side of the rhombic prism. Through the light path in the prism, the 4-way signal light is reflected in a Z shape, and the 4-way signal light is multiplexed into a bundle of light transmission or a bundle of 4-way signal light is demultiplexed into 4-way single signal light. In this scheme, the optical path of the 4-way signal light is inconsistent, so the loss also has a gap. In theory, the larger the optical path, the larger the insertion loss. The coupling of the transmitting light path and the collimated light beam is very sensitive to angle, so the patch precision is high. The number of layers of the narrowband filter coating used is as high as hundreds, and the stress in the filter is large, with low yield and high cost.

[0004] The AWG technology has more stringent requirements for chip size and cost constraints, and due to the limited width of the chip, the loss is higher than that of the TFF type WDM, and the channel quality is also poorer, making it difficult to apply in high-speed optical module Demux. Therefore, there is an urgent need for a wave division multiplexing device based on dichroic mirror for optical module. SUMMARY

[0005] The technical problem to be solved by the utility model is to provide a wave division multiplexing device based on dichroic mirror for optical module, which promotes the miniaturization of the wave division multiplexing device for optical module and reduces the manufacturing cost and assembly difficulty of high-speed optical module.

[0006] The technical scheme adopted by the utility model to solve the above technical problem is: a wave division multiplexing device based on dichroic mirror for optical module, the device comprising RX Circuit, TIA 4CH, PD array, lens array, WDM module, light path turning prism attached to the WDM module, C-Lens lens, receptacle connector, optical fiber connected to the receptacle connector, wherein the WDM module is a prism group composed of multiple rhombic prisms, dichroic mirrors and light path compensation prisms;

[0007] The single beam signal light containing multiple wavelengths transmitted in the optical fiber is transmitted into the device through the receptacle connector, collimated into a parallel light by the C-lens, transmitted into the light path turning prism to prevent the reflected light from being transmitted back to the input light path, demultiplexed into multiple parallel signal lights containing only one wavelength in the WDM module, focused by the lens array, received by the PD array, converted into an electrical signal, amplified by the TIA 4CH, and transmitted to the receiving circuit RXCircuit.

[0008] Further, the WDM module comprises rhombic prisms, first, second, third and fourth rhombic prisms; dichroic mirrors, first, second and third dichroic mirrors; a WDM base and a mounting guide rail; HR films coated on the reflecting surfaces, wherein the reflecting surfaces comprise first, second, third and fourth reflecting surfaces; and AR films coated on the light output surface and the light input surface of the WDM module.

[0009] Further, the first and third dichroic mirrors are long-pass dichroic mirrors, and the second dichroic mirror is a short-pass dichroic mirror. If the incident light is a single beam signal light containing four wavelengths λ1, λ2, λ3 and λ4, the cutoff wavelength of the first dichroic mirror is between λ2 and λ3; the cutoff wavelength of the second dichroic mirror is between λ4 and λ3; and the cutoff wavelength of the third dichroic mirror is between λ2 and λ1.

[0010] Further, when the refractive index of one of the rhombic prisms is less than a preset value, the maximum reflection wavelength of the HR film on the surface of the rhombic prism is greater than the maximum of the multiple incident light wavelengths, and the minimum reflection wavelength is less than the minimum of the multiple incident light wavelengths; when the refractive index of one of the rhombic prisms is greater than the preset value, the surface of the rhombic prism does not need to be coated with the HR film.

[0011] Further, the demultiplexing process in the WDM module comprises: a single beam signal light containing four wavelengths λ1, λ2, λ3 and λ4 is transmitted into the WDM module through the light path turning prism, reflected by the first reflecting surface, and split into a single beam containing two wavelengths λ1 and λ2 and a single beam containing two wavelengths λ3 and λ4 by the first dichroic mirror, wherein the single beam containing two wavelengths λ1 and λ2 is split into two signal lights containing wavelengths λ1 and λ2, respectively, by the third dichroic mirror after being reflected by the second dichroic mirror, and the single beam containing two wavelengths λ3 and λ4 is split into two signal lights containing wavelengths λ3 and λ4, respectively, by the second dichroic mirror after being reflected by the second reflecting surface.

[0012] Further, the single beam light of wavelength λ2 split by the third dichroic mirror and the single beam light of wavelength λ3 split by the second dichroic mirror are emitted from the WDM module through an optical path compensation prism; the single beam light of wavelength λ1 split by the third dichroic mirror and the single beam light of wavelength λ4 split by the second dichroic mirror are reflected by the third reflecting surface and the fourth reflecting surface respectively and emitted from the WDM module.

[0013] Further, for the four single beam signal lights of wavelengths λ1, λ2, λ3 and λ4 obtained by the WDM module through the demultiplexing process, the interval between the single beam signal light of wavelength λ1 and the single beam signal light of wavelength λ2 is equal to the length of the side of the first rhombic prism; the interval between the single beam signal light of wavelength λ2 and the single beam signal light of wavelength λ3 is equal to the length of the side of the fourth rhombic prism, and the interval between the single beam signal light of wavelength λ3 and the single beam signal light of wavelength λ4 is equal to the length of the side of the second rhombic prism.

[0014] Further, the WDM module is also adapted for a multiplexing optical path, that is, the four single beam signal lights of wavelengths λ1, λ2, λ3 and λ4 enter the WDM module in reverse to the demultiplexing optical path of the WDM module and are coupled into a single beam light containing the four wavelengths λ1, λ2, λ3 and λ4.

[0015] Further, the multiplexing process in the WDM module includes that the four parallel single beam signal lights of wavelengths λ1, λ2, λ3 and λ4 enter the WDM module through a lens array, wherein the single beam signal light of wavelength λ1 is reflected to the third dichroic mirror after the third reflecting surface, combined with the single beam signal light of wavelength λ2 through the optical path compensation prism into a single beam signal light containing the two wavelengths λ1 and λ2 and transmitted to the first dichroic mirror, and another single beam signal light containing the two wavelengths λ3 and λ4 is obtained in the same way, the single beam signal light containing the two wavelengths λ3 and λ4 is reflected to the first dichroic mirror through the second reflecting surface, combined with the single beam signal light containing the two wavelengths λ1 and λ2 into a single beam light containing the four wavelengths λ1, λ2, λ3 and λ4.

[0016] The utility model also provides a kind of optical module, and the optical module contains the above-mentioned optical module based on dichroic mirror's wavelength division multiplexing device.

[0017] The utility model has the advantages that:

[0018] The utility model discloses a kind of Wavelength Division Multiplexing devices and optical modules based on dichroic mirror for optical module, setting WDM module containing rhombic prism, dichroic mirror and optical path compensation prism carry out multiplexing and demultiplexing of light beam.The WDM module of the utility model has no influence on the spacing and angle of light beam in the length of optical path parallel direction, can realize the substantial compression of device size, promote miniaturization, simultaneously, the utility model does not contain narrowband filter in Z-Block and waveguide chip in AWG, and dichroic mirror uses quantity is less, reduce the manufacturing cost of device, in addition, the light entrance surface and light exit surface of the WDM module of the utility model are plane, can be assembled according to requirement with adjacent connector device pasting on surface, reduce assembly difficulty and coupling difficulty.

[0019] Further, the utility model is coated with AR film on the light entrance surface and light exit surface of WDM module, can reduce the Fresnel reflection when signal light passes through different medium interface, to reduce the attenuation of optical signal.

[0020] Further, the utility model sets up optical path turning prism, can avoid the reflected light in rear-end optical path back through into front-end optical path to thereby affect the realization of device function.

[0021] Further, the utility model guarantees the parallelism of each reflecting surface and dichroic mirror surface to guarantee the parallelism of light beam, reduce the assembly difficulty of device. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is overall assembly drawing for the utility model embodiment;

[0023] Fig. 2 (a) is the WDM module assembly drawing of the utility model embodiment;

[0024] Fig. 2 (b) is the film coating schematic drawing of the utility model embodiment WDM module;

[0025] Fig. 2 (c) is the side schematic drawing of rhombic prism in the WDM module of the utility model embodiment;

[0026] Figure 3 It is local schematic drawing for the utility model embodiment.

[0027] Reference numerals: 1. RX Circuit; 2. TIA 4CH; 3. PD array; 4. Lens array; 5. Optical path compensation prism; 6-1. First oblique prism; 6-2. Second oblique prism; 6-3. Third oblique prism; 6-4. Fourth oblique prism; 7-1. First dichroic mirror; 7-2. Second dichroic mirror; 7-3. Third dichroic mirror; 8. WDM base and mounting rail; 9. HR film; 10. Optical path deflection prism; 11. C-Lens lens; 12. Receptacle connector; 13. Optical fiber; 14-1. First reflecting surface; 14-2. Second reflecting surface; 14-3. Third reflecting surface; 14-4. Fourth reflecting surface; 15-1. Side of the first oblique prism; 15-2. Side of the second oblique prism; 15-3. Side of the third oblique prism; 15-4. Side of the fourth oblique prism. Detailed Implementation

[0028] Example 1

[0029] This embodiment provides a wavelength division multiplexing device based on a dichroic mirror for optical modules, such as... Figure 1 As shown, it includes optical fiber 13, receptacle connector 12, C-Lens lens 11, optical path deflection prism 10, WDM module, lens array 4, PD array 3, TIA 4CH 2, and RX Circuit 1. The assembly structure of lens array 4, PD array 3, TIA 4CH 2, and RX Circuit 1 is as follows... Figure 3 As shown.

[0030] Specifically, as shown in Figure 2(a), the WDM module includes an optical path compensation prism 5; a first rhombic prism 6-1, a second rhombic prism 6-2, a third rhombic prism 6-3, and a fourth rhombic prism 6-4; a first dichroic mirror 7-1, a second dichroic mirror 7-2, and a third dichroic mirror 7-3; a WDM base and mounting rail 8; an HR film 9 deposited on each reflective surface, wherein the reflective surfaces include a first reflective surface 14-1, a second reflective surface 14-2, a third reflective surface 14-3, and a fourth reflective surface 14-4; and an AR film deposited on the light-emitting surface and the light-receiving surface of the WDM module.

[0031] Specifically, as shown in Figure 2(b), when the refractive index of the prism is less than 1.4142, the maximum value of the reflected wavelength of each HR film is greater than the maximum value of the wavelength of various incident light in the device, and the minimum value is less than the minimum value of the wavelength of various incident light in the device; when the refractive index of the prism is greater than 1.4142, the first reflecting surface 14-1, the second reflecting surface 14-2, the third reflecting surface 14-3 and the fourth reflecting surface 14-4 can be uncoated, and the signal light undergoes total internal reflection on the prism surface.

[0032] Specifically, the position relationship of the side 15-1 of the first rhomboid prism 6-1, the side 15-2 of the second rhomboid prism 6-2, the side 15-3 of the third rhomboid prism 6-3 and the side 15-4 of the fourth rhomboid prism 6-4 can be obtained from Fig. 2(c). The distance between the λ1 and λ2 light beams split by the third dichroic mirror 7-3 is equal to the length of the side 15-1 of the first rhomboid prism 6-1, the distance between the λ2 and λ3 light beams is equal to the length of the side 15-4 of the fourth rhomboid prism 6-4, and the distance between the λ3 and λ4 light beams is equal to the length of the side 15-2 of the second rhomboid prism 6-2. That is, the beam spacing and angle of the λ1, λ2, λ3 and λ4 four-channel signal light are independent of the thickness of the parallel direction prism of the optical path, so that the device can be compressed in this direction, thereby reducing the size.

[0033] Specifically, the parallelism of the light beams is ensured by ensuring the parallelism of the reflecting surface and the dichroic mirror surface.

[0034] Specifically, the input and output surfaces of the WDM module of the device are planes, and the light path turning prism can be attached to the output or input surface of the WDM module to reduce the assembly and coupling difficulty.

[0035] Embodiment 2

[0036] The embodiment provides a light path control method for implementing the demultiplexing of light beams in the dichroic mirror-based wavelength division multiplexing device for optical modules described in Embodiment 1.

[0037] Specifically, a single beam of signal light containing four wavelengths λ1, λ2, λ3 and λ4 is transmitted into the device by the Receptacle connector 12, collimated into a parallel light beam after the C-Lens lens 11, enters the WDM module for demultiplexing into four parallel signal light beams of different wavelengths after passing through the light path turning prism 10 for preventing the reflected light from being transmitted back to the input light path, and is focused by the lens array 4 and received by the PD array 3, so as to convert the optical signal into an electrical signal, amplify the signal by the TIA 4CH 2, and transmit the signal to the receiving end circuit RX Circuit 1.

[0038] Further, the process of demultiplexing in the WDM module includes that the first dichroic mirror 7-1 divides the single beam of incident light containing four wavelengths λ1, λ2, λ3, λ4 into a single beam containing two wavelengths λ1, λ2 and a single beam containing two wavelengths λ3, λ4, wherein the single beam containing two wavelengths λ1, λ2 is reflected and then divided into λ1 and λ2 by the third dichroic mirror 7-3, the single beam containing two wavelengths λ3, λ4 is transmitted and then the light path is turned at the second reflecting surface 14-2, and then divided into λ3, λ4 by the second dichroic mirror 7-2, λ2 divided by the third dichroic mirror 7-3 and λ3 divided by the second dichroic mirror 7-2 are emitted from the WDM module through the light path compensation prism 5, and the single beam with wavelength λ1 divided by the third dichroic mirror 7-3 and the single beam with wavelength λ4 divided by the second dichroic mirror 7-2 are respectively reflected at the third reflecting surface 14-3 and the fourth reflecting surface 14-4 and then emitted from the WDM module.

[0039] Embodiment 3

[0040] The embodiment provides a light path control method for implementing beam multiplexing in the dichroic mirror-based wavelength division multiplexing device for the optical module described in Embodiment 1.

[0041] Specifically, the electrical signal of the receiving circuit RX Circuit 1 is attenuated by the TIA 4CH2, received by the PD array 3, converted into an optical signal, and then diverged into four parallel signal lights by the lens array 4, the four parallel signal lights are multiplexed into a single beam containing four wavelengths in the WDM module, transmitted through the light path turning prism 10 for preventing the reflected light from being transmitted back to the input light path, collimated by the C-Lens lens 11, and then transmitted out of the device from the receptacle connector 12 through the optical fiber 13.

[0042] Further, the process of multiplexing in the WDM module includes that the four parallel signal lights with wavelengths λ1, λ2, λ3, λ4 respectively enter the WDM module through the lens array 4, wherein the signal light with wavelength λ1 is reflected to the third dichroic mirror 7-3 after the third reflecting surface 14-3, combined with λ2 passing through the light path compensation prism 5 into a single beam containing two wavelengths λ1, λ2, the signal light with wavelength λ4 is reflected to the third dichroic mirror 7-3 after the fourth reflecting surface 14-4, combined with λ3 passing through the light path compensation prism 5 into a single beam containing two wavelengths λ3, λ4, and then reflected to the first dichroic mirror 7-1 by the second reflecting surface 14-2, and combined with the single beam containing two wavelengths λ1, λ2 into a single beam containing four wavelengths λ1, λ2, λ3, λ4.

[0043] Embodiment 4

[0044] The embodiment provides a kind of optical module, which contains the wavelength division multiplexing device for optical module in embodiment 1.

[0045] Preferably, the optical module can be a high-speed optical module, since the wavelength division multiplexing device for optical module in embodiment 1 has the characteristics that the transverse length has no effect on the spacing and angle of the light beams, a smaller number of dichroic mirrors is used, and the entrance and exit light surfaces are both flat, compared with other prior art, the high-speed optical module can achieve smaller size, lower manufacturing cost and lower assembly difficulty, etc. under the premise of ensuring higher channel transmission quality.

[0046] In summary, the utility model discloses a kind of wavelength division multiplexing device for optical module based on dichroic mirror and optical module, setting up the WDM module containing rhombic prism, dichroic mirror and optical path compensation prism carries out the multiplexing and demultiplexing of light beam, and only through the specific side length of rhombic prism determines the light beam spacing, it is favorable to reduce product size, promote the miniaturization of wavelength division multiplexing device in optical module, while reduce the manufacturing cost and assembly difficulty of high-speed optical module.

[0047] It should be understood that, for those skilled in the art, improvements or changes can be made according to the above description, and all such improvements and changes shall fall within the scope of protection of the appended claims of the utility model.

Claims

1. A wavelength division multiplexing device based on a dichroic mirror for an optical module, characterized in that, The device includes an RX Circuit (1); a TIA 4CH (2); a PD array (3); a lens array (4); a WDM module; an optical path deflection prism (10) attached to the WDM module; a C-Lens lens (11); a Receptacle connector (12); and an optical fiber (13) connecting the Receptacle connector (12); wherein the WDM module is a prism group composed of multiple orthorhombic prisms, dichroic mirrors, and optical path compensation prisms; A single beam of signal light containing multiple wavelengths is transmitted in the optical fiber (13). After being transmitted into the device through the Receptacle connector (12), it is collimated into a parallel beam by the C-Lens lens (11). It then enters the optical path deflection prism (10) to prevent reflected light from being transmitted back to the input optical path. It is then transmitted into the WDM module and demultiplexed into multiple beams of parallel signal light containing only one wavelength. The multiple beams of parallel signal light are focused by the lens array (4), received by the PD array (3), converted into electrical signals, amplified by the TIA 4CH (2), and transmitted to the receiving circuit RX Circuit (1).

2. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 1, characterized in that, The WDM module includes: rhombic prisms: a first rhombic prism (6-1), a second rhombic prism (6-2), a third rhombic prism (6-3), and a fourth rhombic prism (6-4); dichroic mirrors: a first dichroic mirror (7-1), a second dichroic mirror (7-2), and a third dichroic mirror (7-3); a WDM base and mounting rails (8); HR films (9) respectively deposited on the reflective surfaces of different rhombic prisms, wherein the reflective surfaces include a first reflective surface (14-1), a second reflective surface (14-2), a third reflective surface (14-3), and a fourth reflective surface (14-4); and AR films deposited on the light-emitting surface and the light-receiving surface of the WDM module.

3. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 2, characterized in that, The first dichroic mirror (7-1) and the third dichroic mirror (7-3) are long-pass dichroic mirrors, and the second dichroic mirror (7-2) is a short-pass dichroic mirror; if the incident light includes , , , Four wavelengths of single-beam signal light, the cutoff wavelength of the first dichroic mirror (7-1) is between and Between, the cutoff wavelength of the second dichroic mirror (7-2) is between and The cutoff wavelength of the third dichroic mirror (7-3) is between [a certain value] and [a certain value]. and between.

4. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 2, characterized in that, When the refractive index of the rhombic prism is less than the preset value, the maximum value of the reflected wavelength of the HR film on the reflecting surface of the rhombic prism is greater than the maximum value among the various incident light wavelengths contained in the device, and the minimum value of the reflected wavelength is less than the minimum value among the various incident light wavelengths contained in the device; when the refractive index of one of the rhombic prisms is greater than the preset value, the reflecting surface of the rhombic prism does not need to be coated with an HR film.

5. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 3, characterized in that, The demultiplexing process in the WDM module includes: , , , Four wavelengths of single-beam signal light enter the WDM module through the optical path deflection prism (10), are reflected by the first reflecting surface (14-1), and are split into beams containing [various wavelengths] by the first dichroic mirror (7-1). , Two wavelengths of single beam light and containing , A single beam of light with two wavelengths, containing , Two beams of light of different wavelengths are reflected by the first dichroic mirror (7-1) and then split into two beams of different wavelengths by the third dichroic mirror (7-3). and Signal light, containing , Two single beams of light of different wavelengths are transmitted through the first dichroic mirror (7-1) and reflected at the second reflecting surface (14-2). The light is then split into two beams with wavelengths of [wavelengths missing] at the second dichroic mirror (7-2). , The signal light.

6. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 5, characterized in that, The wavelength separated by the third dichroic mirror (7-3) is The single beam of light and the wavelength separated by the second dichroic mirror (7-2) are A single beam of light is emitted from the WDM module through the optical path compensation prism (5); the wavelength separated by the third dichroic mirror (7-3) is... The single beam of light and the wavelength separated by the second dichroic mirror (7-2) are The single beam of light is reflected by the third reflective surface (14-3) and the fourth reflective surface (14-4) respectively, and then emitted from the WDM module.

7. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 6, characterized in that, The four wavelengths obtained by the WDM module through the demultiplexing process are as follows: , , , The signal light has a wavelength of A single beam of signal light with a wavelength of The spacing between the single beams of signal light is equal to the length of the side (15-1) of the first rhomboid prism (6-1); the wavelength is A single beam of signal light with a wavelength of The spacing of the single-beam signal light is equal to the length of the side (15-4) of the fourth rhomboid prism (6-4), and the wavelength is... A single beam of signal light with a wavelength of The spacing of the single beam signal light is equal to the length of the side (15-2) of the second rhomboid prism (6-2).

8. The wavelength division multiplexing device based on a dichroic mirror for optical modules according to claim 1, characterized in that, The WDM module is also compatible with multiplexed optical paths, i.e., the four wavelengths are respectively , , , The parallel signal light enters the WDM module in reverse direction from the demultiplexed optical path of the WDM module, and couples to form a signal containing... , , , A single beam of light with four wavelengths.

9. The wavelength division multiplexing device for optical modules based on dichroic mirrors according to claim 8, characterized in that, The multiplexing process in the WDM module includes four beams with wavelengths of... , , , The parallel signal light passes through the lens array (4) and enters the WDM module, where the wavelength is... The signal light is reflected by the third reflecting surface (14-3) and then onto the third dichroic mirror, where it interacts with the light passing through the optical path compensation prism (5). Bundles are included , Two single-beam signal lights of different wavelengths are transmitted to the first dichroic mirror (7-1) and, in the same manner, obtain signals containing... , Another single beam of signal light of two wavelengths, containing , Two single-beam signal lights of different wavelengths are reflected by the second reflecting surface (14-2) to the first dichroic mirror (7-1), and then... , Two wavelengths of single-beam signal light combined to form a beam containing , , , A single beam of light with four wavelengths.

10. An optical module, characterized in that, The optical module includes a wavelength division multiplexing device based on a dichroic mirror for optical modules as described in any one of claims 1-9.

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