Optical receiving sub-module and optical module

Abstract

The invention relates to the technical field of optical communication, and provides a light receiving sub-module which comprises an optical fiber adapter, input light emitted by a light emitting end face of the optical fiber adapter deviates towards a Y-axis direction along an X-axis direction and then is obliquely emitted, the input light sequentially passes through a collimating lens and a convergent lens, the collimating lens and the convergent lens are obliquely arranged, and the collimating lens and the convergent lens are obliquely arranged. And the optical axis of the inclined collimating lens and the optical axis of the inclined convergent lens coincide with the input light. The invention further provides an optical module which comprises the optical receiving secondary module. By obliquely arranging the collimating lens and the convergent lens, the input light can pass through the optical axis of the collimating lens, the optical axis of the convergent lens and the light beam collimated by the center of the collimating lens, so that the influence of aberration caused by miscoincidence of the center of the light beam and the optical axis of the collimating lens can be eliminated, and the error code of optical signal transmission is reduced; and the performance of the optical module is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to an optical receiving submodule and an optical module. Background Art

[0002] Figure 1 This is a typical optical path diagram of a ROSA. In order to prevent the reflected light from affecting the photodiode, the fiber end face of the fiber adapter of the optical receiving submodule is usually designed as a bevel, and the inclination of the bevel is usually 6 degrees. The light beam from the fiber adapter is emitted at an angle of about 2.8 degrees to the optical axis. The light from the fiber adapter is collimated by the collimating lens and then converged by the converging lens to the photosensitive surface of the photodiode to complete the photoelectric conversion. Figure 1 The light beam shown in the figure will be offset from the optical axis of the collimating lens after it comes out of the fiber adapter and pass through the collimating lens (the center of the light beam does not coincide with the optical axis of the collimating lens, but is offset by a distance), and then converge to the photosensitive surface of the photodiode through the center of the converging lens. Since the light beam coming out of the fiber adapter is offset from the optical axis when passing through the collimating lens, that is, it does not pass through the optical axis of the collimating lens, the light spot that finally converges on the photosensitive surface of the photodiode will have aberration, thereby affecting the signal transmission quality, especially for single-channel products with a rate of more than 100G, this effect is more obvious, which will significantly increase the bit error rate of optical signal transmission, thereby reducing the performance of the optical module. Summary of the invention

[0003] The object of the present invention is to provide a light receiving sub-module and an optical module, which can at least solve some of the defects in the prior art.

[0004] To achieve the above-mentioned purpose, an embodiment of the present invention provides the following technical solution: an optical receiving submodule, comprising an optical fiber adapter, wherein the input light emitted from the light-emitting end face of the optical fiber adapter is offset along the X-axis direction toward the Y-axis direction and then emitted obliquely, and the input light passes through a collimating lens and a converging lens in sequence, and the collimating lens and the converging lens are both tilted, and the optical axis of the collimating lens after tilting and the optical axis of the converging lens after tilting both coincide with the input light.

[0005] Furthermore, the angle at which the collimating lens and the converging lens are offset relative to the X-axis direction is consistent with the angle at which the input light is offset relative to the X-axis direction.

[0006] Furthermore, the input light is offset by an angle of 2.8 degrees relative to the X-axis direction.

[0007] Furthermore, the angle between the optical fiber end face of the optical fiber adapter and the X-axis direction is 84 degrees.

[0008] Furthermore, it also includes an optical demultiplexer, which is arranged on the optical path between the collimating lens and the converging lens.

[0009] Furthermore, the angle at which the optical demultiplexer is offset relative to the X-axis direction is consistent with the angle at which the input light is offset relative to the X-axis direction.

[0010] Furthermore, the number of light paths decomposed by the converging lens is the same as that by the optical demultiplexer and they correspond one to one.

[0011] Furthermore, it also includes photodiodes for receiving the light converged by the converging lenses, and the number of the converging lenses is the same as the number of the photodiodes.

[0012] The embodiment of the present invention provides another technical solution: an optical module, comprising the above-mentioned optical receiving sub-module.

[0013] Compared with the prior art, the beneficial effects of the present invention are: a light receiving submodule, by tilting the collimating lens and the converging lens, allows the input light to pass through the optical axis of the collimating lens and the optical axis of the converging lens. The light beam after passing through the center of the collimating lens can eliminate the influence of aberration caused by the misalignment of the center of the light beam with the optical axis of the collimating lens, thereby reducing the bit error of optical signal transmission and improving the performance of the optical module. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the optical path of a conventional light receiving submodule (top view);

[0015] Figure 2 A schematic diagram of a light path of a light receiving sub-module provided in an embodiment of the present invention (top view);

[0016] Figure 3 A schematic diagram of a multi-path light path of a light receiving sub-module provided in an embodiment of the present invention (top view);

[0017] In the accompanying drawings: 1-fiber adapter; 2-collimating lens; 3-converging lens; 4-optical demultiplexer; 5-photodiode; A-optical axis of the collimating lens and the optical axis of the converging lens; B-X axis direction. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 2, an embodiment of the present invention provides an optical receiving submodule, including an optical fiber adapter 1, the input light emitted from the light emitting end face of the optical fiber adapter 1 is offset along the X-axis direction B toward the Y-axis direction and then emitted at an angle, the input light passes through a collimating lens 2 and a converging lens 3 in sequence, the collimating lens 2 and the converging lens 3 are both tilted, and the optical axis of the tilted collimating lens and the optical axis of the tilted converging lens 3 both coincide with the input light. In this embodiment, by tilting the collimating lens 2 and the converging lens 3, the input light can pass through the optical axis of the collimating lens 2 and the optical axis of the converging lens 3, and the light beam that passes through the center of the collimating lens 2 can eliminate the influence of aberration caused by the non-coincidence between the center of the light beam and the optical axis of the collimating lens 2, thereby reducing the bit error of optical signal transmission and improving the performance of the optical module. Specifically, in a conventional optical path such as Figure 1 As shown, the collimating lens 2 and the converging lens 3 are mounted normally along the X-axis direction without angular deviation, so that the optical axis of the collimating lens and the optical axis A of the converging lens are both set along the X-axis direction. Since the light emitting end face of the optical fiber adapter is inclined, the optical fiber end face is usually an inclined surface, that is, Figure 1 As shown, the optical axis A is offset by 84 degrees. Then the input light from the fiber adapter 1 will be emitted at an angle of about 2.8 degrees with the optical axis of the collimating lens and the optical axis A of the converging lens, which will cause the input light to be offset from the optical axis of the collimating lens 2, and will not pass through the optical axis of the collimating lens 2, resulting in aberration of the light spot, which will affect the transmission quality of the signal, especially for single-channel products with a rate of more than 100G. The impact will be more obvious, and the increase in rate is driven by the field of optical modules. Therefore, if the aberration problem is not improved, the performance of future optical module products will not be high, or correction from other more complex angles will be required, which will undoubtedly increase the cost. The present embodiment ingeniously utilizes the tilted setting of the collimating lens 2 and the converging lens 3, so that the optical axis of the tilted collimating lens and the optical axis of the converging lens 3 coincide with the input light, thereby solving the above technical problems. This method only adjusts the mounting angles of the collimating lens 2 and the converging lens 3. For example, when mounting on a PCB board, the two lenses are offset by a certain angle along the X-axis direction toward the Y-axis direction, thereby changing the direction of the optical axis of the collimating lens and the optical axis of the converging lens to match the offset direction of the input light, thereby simply solving the above technical problems.

[0020] See also Figure 2 , the angle at which the collimating lens 2 and the converging lens 3 are offset relative to the X-axis direction B is consistent with the angle at which the input light is offset relative to the X-axis direction B. In this embodiment, the direction in which the collimating lens 2 and the converging lens 3 are offset can be matched according to the direction in which the input light is offset and emitted. Preferably, the angle at which the input light is offset relative to the X-axis direction B is 2.8 degrees, and the angle between the optical fiber end face of the optical fiber adapter 1 and the X-axis direction is 84 degrees.

[0021] See also Figure 3 , the optical receiving submodule is not only suitable for single-channel but also for multiplexing. Specifically, the optical receiving submodule also includes an optical demultiplexer 4, and the optical demultiplexer 4 is arranged on the optical path between the collimating lens 2 and the converging lens 3. In this embodiment, the input light can be decomposed into multiple light paths by the optical demultiplexer 4. After adopting the optical demultiplexer 4, the method of solving the optical axis offset problem is consistent with the method of solving the problem of the collimating lens 2 and the converging lens 3 mentioned above. The angle of the optical demultiplexer 4 relative to the X-axis direction B can be adjusted to be consistent with the angle of the input light relative to the X-axis direction B. Specifically, during mounting, the optical demultiplexer 4 can be offset by a certain angle along the X-axis direction toward the Y-axis direction to form an inclined posture with an angle of b, and the angle b is consistent with the angle a of the input light relative to the X-axis direction B. For example, both angle a and angle b can be 2.8 degrees. This embodiment shows four-path light. The light beam from the optical fiber adapter 1 is collimated by the center of the collimating lens 2 and then divided into four paths of light by the optical demultiplexer 4. Then, the light beams are respectively converged to the photosensitive surfaces of four photodiodes 5 by four converging lenses 3.

[0022] To further optimize the above solution, please refer to Figure 3 The number of light paths decomposed by the converging lens 3 and the light demultiplexer 4 is the same and corresponds one to one. In this embodiment, when there are four light paths, four converging lenses 3 and four photodiodes 5 are provided accordingly.

[0023] See also Figure 2 and Figure 3 The optical receiving submodule further includes a photodiode 5 for receiving the light converged by the converging lens 3, and the number of the converging lens 3 is the same as that of the photodiode 5. In this embodiment, the photodiode 5 is used to receive the light beam converged by the converging lens 3, and the number of the photodiode 5 is consistent with the number of the light paths. As described above, the multi-path light beams decomposed by the optical demultiplexer 4 will be incident on the photosensitive surfaces of the corresponding number of photodiodes 5.

[0024] See also Figure 2 and Figure 3 , an embodiment of the present invention provides an optical module, including the above-mentioned light receiving submodule. The above-mentioned light receiving submodule is used in the optical module to improve the performance of the optical module. Specifically, by tilting the collimating lens 2 and the converging lens 3, the input light can pass through the optical axis of the collimating lens 2 and the optical axis of the converging lens 3. The light beam collimated by the center of the collimating lens 2 can eliminate the influence of aberration caused by the misalignment of the center of the light beam with the optical axis of the collimating lens 2, thereby reducing the bit error of the optical signal transmission and improving the performance of the optical module.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An optical receiving submodule, comprising an optical fiber adapter, characterized in that: The input light emitted from the light-emitting end face of the optical fiber adapter is offset along the X-axis direction toward the Y-axis direction and then emitted obliquely. The input light passes through a collimating lens and a converging lens in sequence. Both the collimating lens and the converging lens are tilted, and the optical axis of the tilted collimating lens and the optical axis of the tilted converging lens both coincide with the input light.

2. The optical receiving submodule according to claim 1, wherein: The angle at which the collimating lens and the converging lens are offset relative to the X-axis direction is consistent with the angle at which the input light is offset relative to the X-axis direction.

3. The optical receiving submodule as claimed in claim 2, wherein: The input light is offset by 2.8 degrees relative to the X-axis direction.

4. The light receiving submodule according to claim 1, wherein: The angle between the optical fiber end face of the optical fiber adapter and the X-axis direction is 84 degrees.

5. The light receiving submodule as claimed in claim 1, wherein: It also includes an optical demultiplexer, which is arranged on the optical path between the collimating lens and the converging lens.

6. The light receiving submodule as claimed in claim 5, wherein: The angle at which the optical demultiplexer is offset relative to the X-axis direction is consistent with the angle at which the input light is offset relative to the X-axis direction.

7. The light receiving submodule as claimed in claim 5, wherein: The number of light paths decomposed by the converging lens is the same as that by the optical demultiplexer and they correspond one to one.

8. The light receiving submodule according to claim 1 or 5, characterized in that: The device further comprises photodiodes for receiving the light focused by the focusing lenses, and the number of the focusing lenses is the same as the number of the photodiodes.

9. An optical module, characterized in that: It comprises the optical receiving submodule as claimed in any one of claims 1 to 8.

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