A multiplexed optical transmission submodule

Abstract

This invention relates to the field of optical communication technology and provides a multiplexed optical emission submodule, including an optical multiplexing component, multiple collimating lenses, and multiple lasers. Each collimating lens corresponds one-to-one with each laser, and each collimating lens collimates the light emitted by its corresponding laser. A bandpass filter is provided at the light incident end of the optical multiplexing component. The light emitted by each laser is combined by the optical multiplexing component into two parallel beams that are close to each other and are emitted from the output end of the optical multiplexing component. This invention reduces the number of bandpass filters used from three to one, significantly reducing the cost of the optical multiplexing component.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to a multiplexed optical transmission submodule. Background Technology

[0002] With the development of the optical communication industry, the amount of data that needs to be transmitted is increasing, leading to a greater demand for optical modules. This also places higher demands on cost control of optical modules. Therefore, reducing the cost of optical modules and enhancing their market competitiveness has become increasingly important. Figure 1 This is a schematic diagram of the optical path of a traditional four-way multiplexed optical transmitter submodule. It mainly includes a PCB board, laser 7, collimating lens 6, optical multiplexing assembly 4, displacement prism 3, converging lens 2, and fiber optic adapter 1. Three bandpass filters 5 corresponding to different wavelengths are attached to the light incident end of the optical multiplexing assembly 4. Four lasers emitting different wavelengths are arranged at equal intervals. The light emitted by the four lasers is collimated by the lens, then multiplexed into a single path by the optical multiplexing assembly, and finally coupled into the fiber optic adapter for output via the displacement prism and converging lens. The bandpass filters in the optical multiplexing assembly are relatively expensive due to their complex manufacturing process. Summary of the Invention

[0003] The purpose of this invention is to provide a multiplexed optical emission submodule that can significantly reduce the cost of optical multiplexing components by reducing the use of bandpass filters.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a multiplexed optical emission submodule, comprising an optical multiplexing component, multiple collimating lenses, and multiple lasers, wherein each collimating lens corresponds one-to-one with each laser, and each collimating lens collimates the light emitted by its corresponding laser. A bandpass filter is provided at the light incident end of the optical multiplexing component, and the light emitted by each laser is combined by the optical multiplexing component into two parallel beams that are close to each other and emitted through the output end of the optical multiplexing component.

[0005] Furthermore, there are four lasers and four collimating lenses; the distance between the light emitted by the first laser and the light emitted by the second laser is between 200 and 400 μm, and the distance between the light emitted by the third laser and the light emitted by the fourth laser is also between 200 and 400 μm, and the distance between the light emitted by the first laser and the light emitted by the second laser is equal to the distance between the light emitted by the third laser and the light emitted by the fourth laser.

[0006] Furthermore, the distance between the light emitted by the first laser and the light emitted by the second laser, and the distance between the light emitted by the third laser and the light emitted by the fourth laser, are both 300 μm.

[0007] Furthermore, after passing through the optical multiplexing component and the bandpass filter, the light emitted by the first laser and the light emitted by the third laser are combined into a first optical path, and the light emitted by the second laser and the light emitted by the fourth laser are combined into a second optical path. The first optical path and the second optical path are parallel and the distance between them is between 200 and 400 μm.

[0008] Furthermore, each of the lasers is attached to the substrate, and the position of the light emitted by the laser is adjusted by adjusting the position of the laser on the substrate.

[0009] Furthermore, the light emitted from the light emitting end of the optical multiplexing component is deflected by a displacement prism.

[0010] Furthermore, the light, after being deflected by the displacement prism, enters the converging lens and is then coupled into the fiber optic adapter.

[0011] Furthermore, the collimating lens is an aspherical lens with a partially cut-off aspherical surface.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] 1. The number of bandpass filters used has been reduced from 3 to 1, which significantly reduces the cost of the optical multiplexing assembly.

[0014] 2. The optical path lengths of the light emitted by the first and second lasers to the fiber optic adapter are significantly reduced, which lowers the difficulty of coupling and enhances the stability of the optical path. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the optical path of a traditional four-way multiplexed optical transmission submodule;

[0016] Figure 2 This is a schematic diagram of the optical path of a multiplexed optical emission submodule provided in an embodiment of the present invention;

[0017] Figure 3 for Figure 2 Detailed schematic diagram;

[0018] Figure 4 A schematic diagram illustrating the effect of the optical fiber incident light angle on the coupling efficiency of a multiplexed optical transmitting submodule provided in an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of the optical path of parallel light entering a converging lens in a multiplexed optical emission submodule provided in an embodiment of the present invention;

[0020] In the attached figures, the following labels are used: 1-Fiber optic adapter; 2-Converging lens; 3-Displacement prism; 4-Optical multiplexing assembly; 5-Bandpass filter; 6-Collimating lens; 7-Laser; 8-Substrate; 9-Reflective coating; 10-Antireflective coating; 11-First optical path; 12-Second optical path. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 2 to 5 This invention provides a multiplexed optical emission submodule, including an optical multiplexing component 4, multiple collimating lenses 6, and multiple lasers 7. Each collimating lens 6 corresponds one-to-one with each laser 7, and each collimating lens 6 collimates the light emitted by its corresponding laser 7. A bandpass filter 5 is provided at the light incident end of the optical multiplexing component 4. The light emitted by each laser is combined into two parallel beams that are close to each other and emitted from the output end of the optical multiplexing component. In this embodiment, by cleverly adjusting the position of the light emitted by the laser 7, the number of bandpass filters 5 can be reduced from 3 to 1, significantly reducing the cost of the optical multiplexing component 4.

[0023] As an optimized solution for an embodiment of the present invention, please refer to Figures 2 to 5 There are four lasers 7 and four collimating lenses 6. The distance between the light emitted by the first laser and the light emitted by the second laser is between 200 and 400 μm, and the distance between the light emitted by the third laser and the light emitted by the fourth laser is also between 200 and 400 μm. The distance between the light emitted by the first laser and the second laser is equal to the distance between the light emitted by the third laser and the fourth laser. The distance between the light emitted by the first laser and the second laser, and the distance between the light emitted by the third laser and the fourth laser, is 300 μm. For ease of description, the first, second, third, and fourth lasers are... Figure 2 The light is defined sequentially from top to bottom. After passing through the optical multiplexing component 4 and the bandpass filter 5, the light emitted by the first laser and the light emitted by the third laser are combined into the first optical path 11, and the light emitted by the second laser and the light emitted by the fourth laser are combined into the second optical path 12. The first optical path 11 and the second optical path 12 are parallel, and the distance between them is between 200 and 400 μm. Specifically, as shown... Figure 2As shown, taking a CWDM4 laser 7 with four wavelengths as an example, the wavelengths emitted by the four lasers λ1, λ2, λ3, and λ4 are 1271nm, 1291nm, 1311nm, and 1331nm, respectively. The lasers 7 and lenses are arranged with non-equidistant spacing. The distance between the emitting points of the two upper lasers 7 is set at approximately 300µm (because the emitting points of the lasers 7 are close to the center, a certain distance needs to be maintained), such as between 200 and 400µm. The distance between the emitting points of the two lower lasers 7 is the same as the distance between the emitting points of the two upper lasers 7. The distance between the second and third upper lasers 7 can be adjusted according to process requirements; the distance can be made relatively large, typically around 1mm, preferably 1mm. The light emitted by the four lasers 7 is collimated by the collimating lens 6 and then combined by the optical multiplexing component 4 into two parallel beams with a spacing of 300um. The two parallel beams are then converged at an angle by the converging lens 2, one above and one below, and enter the fiber optic adapter 1.

[0024] As an optimized solution for an embodiment of the present invention, please refer to Figures 2 to 5 Each of the lasers 7 is attached to the substrate 8, and the position of the light emitted by the laser 7 is adjusted by adjusting its position on the substrate 8. The light emitted from the light-emitting end of the optical multiplexing assembly 4 is deflected by the displacement prism 3. The light deflected by the displacement prism 3 enters the converging lens 2 and is then coupled into the fiber optic adapter 1. Specifically, as... Figure 3 As shown, in order to make the two upper lasers 7 and the two lower lasers 7 as close as possible, the spacing is about 300um, thereby reducing the loss of coupling efficiency. Figure 3 In the optical multiplexing assembly 4, the reflective film 9 reflects the light emitted by the first and second lasers, and the multiplexed light exits from the antireflective film 10 of the optical multiplexing assembly 4. Laser 7, according to... Figure 3 The optical path is attached to the edge of substrate 8 as shown. After passing through optical multiplexing component 4, λ1 and λ3 combine to form the first optical path 11, and λ2 and λ4 combine to form the second optical path 12. The distance between the combined first optical path 11 and the second optical path 12 is approximately 300 μm. Thus, the first optical path 11 and the second optical path 12 enter the converging lens 2 at a distance of approximately 150 μm offset from the optical axis of the converging lens 2, and are then coupled into the fiber optic adapter 1.

[0025] As an optimized solution for an embodiment of the present invention, please refer to Figures 2 to 5 The collimating lens 6 is an aspherical lens with a partially cut-out surface. In this embodiment, a partially cut-out aspherical lens can be used as the collimating lens 6. The cut-out area can be the adjacent part of two collimating lenses 6. Because after adjusting the position of the laser 7, they are close to each other, and interference between the two collimating lenses 6 can be avoided by cutting out a part of the surface.

[0026] As an optimized solution for an embodiment of the present invention, please refer to Figure 4 and Figure 5 For light near 1310 nm, the coupling efficiency of light entering a single-mode fiber is related to the incident angle as follows: Figure 4 As shown. When light enters the optical fiber at a certain incident angle, the coupling efficiency will be somewhat lost. The parallel light of this invention, after passing through the converging lens 2, couples into the optical fiber adapter 1 at an angle, which also results in a loss of coupling efficiency. For example... Figure 5 As shown, parallel light 1 and parallel light 2 enter the converging lens 2 at a distance of 150 μm from the optical axis of the offset lens, and then converge onto the fiber optic adapter 1. The focal length of the converging lens 2 that we usually use is 2700 μm. The angle at which the parallel light enters the fiber optic adapter 1 after convergence is а = в = 150 / 2700 * 57 = 3.17° (Figure). Figure 4 It can be concluded that the coupling efficiency loss when the parallel light is incident on the optical axis of the offset converging lens 2 at 150µm and converges into the fiber optic adapter 1 is approximately 38%. Under normal circumstances, the coupling efficiency without offset is greater than 60%. Therefore, the coupling efficiency using this invention is approximately 60%*(100-38)% = 37.2%, which translates to a loss of approximately 4.3dB. Taking 100GCWDM4 as an example, the optical power coupled by the optical transmitting submodule can typically reach over 5dBm. Considering the 4.3dB loss, the coupling power using this invention can reach 0.7dBm, while the protocol specifies that the optical power specification for 100GCWDM4 is -6.5 to 2.5dBm, leaving sufficient margin. Therefore, although the coupling efficiency is slightly reduced using this invention, it still meets the specifications and has sufficient margin, thus proving that this module meets the requirements.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multiplexed optical emission submodule, comprising an optical multiplexing component, multiple collimating lenses, and multiple lasers, characterized in that: Each collimating lens corresponds one-to-one with each laser. Each collimating lens collimates the light emitted by its corresponding laser. A bandpass filter is provided at the light incident end of the optical multiplexing component. The light emitted by each laser is combined into two parallel beams that are close to each other by the optical multiplexing component and emitted through the output end of the optical multiplexing component. The collimating lens is an aspherical lens with a partially cut-out aspherical surface to avoid interference between two adjacent collimating lenses.

2. The multiplexed optical transmission submodule as described in claim 1, characterized in that: There are four lasers and four collimating lenses; the distance between the light emitted by the first laser and the light emitted by the second laser is between 200 and 400 μm, and the distance between the light emitted by the third laser and the light emitted by the fourth laser is also between 200 and 400 μm, and the distance between the light emitted by the first laser and the light emitted by the second laser is equal to the distance between the light emitted by the third laser and the light emitted by the fourth laser.

3. The multiplexed optical transmission submodule as described in claim 2, characterized in that: The distance between the light emitted by the first laser and the light emitted by the second laser, and the distance between the light emitted by the third laser and the light emitted by the fourth laser, are both 300 μm.

4. The multiplexed optical transmission submodule as described in claim 2, characterized in that: After passing through the optical multiplexing component and the bandpass filter, the light emitted by the first laser and the light emitted by the third laser are combined into a first optical path, and the light emitted by the second laser and the light emitted by the fourth laser are combined into a second optical path. The first optical path and the second optical path are parallel and the distance between them is between 200 and 400 μm.

5. The multiplexed optical transmission submodule as described in claim 1, characterized in that: Each of the lasers is attached to a substrate, and the position of the light emitted by the laser is adjusted by adjusting the position of the laser on the substrate.

6. The multiplexed optical transmission submodule as described in claim 1, characterized in that: The light emitted from the light emitting end of the optical multiplexing component is deflected by the displacement prism.

7. The multiplexed optical transmission submodule as described in claim 6, characterized in that: After being deflected by the displacement prism, the light enters the converging lens, converges, and is then coupled into the fiber optic adapter.

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