BOX-packaged single-fiber three-transmitting and three-receiving optical device with built-in double-layer light combining and splitting device

Abstract

The BOX-packaged single-fiber three-transmitting and three-receiving optical device comprises a BOX shell, a light combining and splitting assembly is arranged in the BOX shell, the light combining and splitting assembly is of an upper-lower double-layer integrated structure, three groups of receiving detectors are arranged behind the upper layer structure in the left-right direction, and a light inlet is formed in the front side face of the upper layer structure; three groups of emitting lasers are arranged behind the lower-layer structure in the left-right direction, and a light outlet is formed in the front side surface; a beam splitter prism comprising a surface A and a surface B which are parallel up and down is arranged in front of the beam combining and splitting assembly, an optical fiber adapter is arranged in front of the beam splitter prism, the surface A is obliquely located between a light inlet of the upper-layer structure and the optical fiber adapter, and the surface B is obliquely located in front of a light outlet of the lower-layer structure; by means of BOX packaging with a built-in double-layer light combining and splitting assembly, the size of the device is effectively reduced, the port density can be increased by 50%, the packaging technology is simple, the cost is moderate, and the requirement for 50G PON three-mode transmission or other application scenes needing single-fiber three-transmitting and three-receiving can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of optical communication, in particular to a single-fiber triple-transmission and triple-reception optical device with a BOX package integrating a double-layer combined optical splitter device. Background Art

[0002] In the PON access network, the central office OLT of 10G PON has passed the peak deployment period. According to market forecasts, the next three years will be the transition period from 10G PON to 50G PON, and it is expected that 50G PON will start large-scale commercial deployment in 2026.

[0003] During the deployment of 50G PON, it is necessary to be compatible with the triple-mode transmission of three generations of PON (the three generations of PON are GPON, 10G PON, and 50G PON), that is, to meet the transmission requirements of three different wavelengths for both upstream and downstream. Existing traditional PON optical devices have only single-fiber single-transmission and two-reception, single-fiber double-transmission and one-reception, or single-fiber double-transmission and double-reception in the transmission channel, and cannot meet the triple-mode transmission requirements of 50G PON. Therefore, it is necessary to design a single-fiber triple-transmission and triple-reception optical device that can meet the above transmission requirements.

[0004] In addition, with the gradual clarification of the positioning of optoelectronic products in the market, the miniaturization of volume and the improvement of system technology integration density have become symbols defining the progress of optoelectronic products. Although there are already individual integrated optical components with triple-transmission and triple-reception in the prior art, the types are very few, mainly limited by the increase in the number and categories of components, the cumbersome layout and assembly, which increase the production cost, and the product volume inevitably increases and occupies space. Summary of the Utility Model

[0005] To solve the above problems, the utility model provides a single-fiber triple-transmission and triple-reception optical device with a BOX package integrating a double-layer combined optical splitter device, which has a reasonable structure, effectively reduces the device size, can increase the port density by 50%, and has a simple packaging process and moderate cost, and can meet the triple-mode transmission requirements of 50G PON or other application scenarios requiring single-fiber triple-transmission and triple-reception.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A single-fiber triple-transmission and triple-reception optical device with a built-in double-layer integrated optical splitting device in a BOX package, comprising a BOX housing. An integrated optical splitting component is arranged inside the BOX housing. The integrated optical splitting component is an integrated structure including upper and lower double layers. Three receiving detectors are arranged side by side along the left-right direction at the rear of the upper-layer structure of the integrated optical splitting component, and a light input port is opened on the front side surface of the upper-layer structure; three transmitting lasers are arranged side by side along the left-right direction at the rear of the lower-layer structure of the integrated optical splitting component, and a light output port is opened on the front side surface of the lower-layer structure; a beam splitting prism is arranged in the BOX housing in front of the integrated optical splitting component. The beam splitting prism includes an A surface and a B surface arranged in parallel up and down. An optical fiber adapter is arranged in front of the beam splitting prism. The A surface is inclined between the light input port of the upper-layer structure and the optical fiber adapter, and the B surface is inclined in front of the light output port of the lower-layer structure.

[0008] As a further improvement of the above technical solution:

[0009] Light output ports corresponding to the receiving detectors one by one are arranged at intervals along the left-right direction on the rear side surface of the upper-layer structure of the integrated optical splitting component, and a first filter is installed at each light output port; light input ports corresponding to the transmitting lasers one by one are arranged at intervals along the left-right direction on the rear side surface of the lower-layer structure of the integrated optical splitting component, and a second filter is installed at each light input port.

[0010] The light input port on the front side surface of the upper-layer structure of the integrated optical splitting component and the light output port on the front side surface of the lower-layer structure are arranged up and down in the same vertical plane. A first transmission film and a second transmission film are respectively arranged at the light input port and the light output port; a first reflection film is arranged on the front side surface of the integrated optical splitting component on the side of the first transmission film. The beam splitting part of the upper-layer structure of the integrated optical splitting component is formed by the first transmission film, the first reflection film and the first filter; a second reflection film is arranged on the front side surface of the integrated optical splitting component on the side of the second transmission film. The light combining part of the lower-layer structure of the integrated optical splitting component is formed by the second transmission film, the second reflection film and the second filter.

[0011] A first lens is respectively arranged between each first filter and the receiving detector; a second lens is respectively arranged between each second filter and the transmitting laser.

[0012] An isolator is arranged between the front of the light output port of the lower-layer structure of the integrated optical splitting component and the B surface of the beam splitting prism.

[0013] A window is opened on the front side door of the BOX housing in front of the A surface of the beam splitting prism, and a ferrule end lens is installed at the window; the optical fiber adapter is arranged directly opposite to the ferrule end lens.

[0014] The optical fiber adapter is welded on the outer side surface of the BOX housing window.

[0015] The A surface and the B surface are arranged at 45°. The B surface reflects and deflects the horizontal light in the front and back directions emitted from the light outlet of the lower layer structure of the combined beam splitting and combining component by 90° to convert it into vertical light in the up and down directions, and then the A surface reflects and deflects the vertical light by 90° to convert it into horizontal light in the front and back directions. The light input by the fiber optic adapter passes through the A surface and then enters the light inlet of the upper layer structure of the combined beam splitting and combining component.

[0016] The beam splitting prism includes a prism two, a prism one, and a prism three that are sequentially attached from top to bottom. The joint surface between the prism one and the prism two forms the A surface, and the joint surface between the prism one and the prism three forms the B surface. The rear side surface of the prism one is the C surface, and the rear side surface of the prism two is the D surface. The C surface and the D surface are arranged in parallel, and the D surface intersects with the A surface and is arranged at a 45° angle.

[0017] The beam splitting prism is supported and installed on the inner bottom surface of the BOX housing via the bottom surface of the prism three.

[0018] Compared with the prior art, the present utility model has the following beneficial effects:

[0019] The single-fiber triple-transmission and triple-reception optical device of the present utility model effectively reduces the device size through BOX packaging with an internal double-layer combined beam splitting and combining component, can increase the port density by 50%, and has a simple packaging process and moderate cost, meeting the requirements of 50G PON triple-mode transmission or other application scenarios that require single-fiber triple-transmission and triple-reception.

[0020] The present utility model also has the following advantages:

[0021] In the present utility model, the combined beam splitting and combining component for receiving and emitting light beams is designed as an integrated structure with high overall integration. It not only effectively improves the product reliability but also further increases the port integration density. Compared with similar products, the overall size of the device is reduced by half, and the thickness increase is less than 20%. It can be applied to environments that require ultra-small space and are not sensitive to cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an elevation structure diagram of the present utility model.

[0023] Figure 2 It is an elevation optical path schematic diagram of the present utility model.

[0024] Figure 3 It is a top view structure diagram of the present utility model.

[0025] Figure 4 It is an optical path schematic diagram of the present utility model in the top view state.

[0026] Figure 5 It is a perspective view of the light and shadow structure inside the BOX housing of the present utility model (the BOX housing is omitted).

[0027] Figure 6This is a schematic structural diagram of the combined beam splitter component of the present utility model.

[0028] Figure 7 This is a schematic structural diagram of the beam splitting prism of the present utility model.

[0029] Among them: 1. BOX housing; 2. Receiving detector; 3. Transmitting laser; 4. Combined beam splitter component; 5. Isolator; 6. Beam splitting prism; 7. Ferrule end lens; 8. Fiber optic adapter;

[0030] 11. Window;

[0031] 20. Lens 1;

[0032] 30. Lens 2;

[0033] 41. Filter 1; 42. Filter 2; 43. Reflective film 1; 44. Transmissive film 1; 45. Reflective film 2; 46. Transmissive film 2;

[0034] 61. Prism 1; 62. Prism 2; 63. Prism 3; 601. A surface; 602. B surface; 611. C surface; 621. D surface. Specific embodiments

[0035] The following combines the drawings to illustrate the specific embodiments of the present utility model.

[0036] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 shown, a single-fiber triple-transmit triple-receive optical device with a BOX package of an internal double-layer combined beam splitter device in this embodiment includes a BOX housing 1. Inside the BOX housing 1, a combined beam splitter component 4 is arranged. The combined beam splitter component 4 is an integrated structure including upper and lower double layers. Behind the upper structure of the combined beam splitter component 4, three groups of receiving detectors 2 are arranged side by side along the left-right direction, and a light input port is opened on the front side surface of the upper structure; behind the lower structure of the combined beam splitter component 4, three groups of transmitting lasers 3 are arranged side by side along the left-right direction, and a light output port is opened on the front side surface of the lower structure; inside the BOX housing 1 in front of the combined beam splitter component 4, a beam splitting prism 6 is arranged. The beam splitting prism 6 includes an A surface 601 and a B surface 602 arranged in parallel up and down. In front of the beam splitting prism 6, a fiber optic adapter 8 is arranged. The A surface 601 is inclined between the light input port of the upper structure and the fiber optic adapter 8, and the B surface 602 is inclined in front of the light output port of the lower structure.

[0037] In this embodiment, the optical multiplexing / demultiplexing component 4 for transmitting and receiving light beams is designed as an integrated structure with upper and lower double layers, and is packaged in a BOX to form a device. The overall integration degree is high, which not only effectively improves the product reliability, but also further improves the density of port integration. Compared with the same type of products, the overall size of the device is reduced by half, and the thickness increase is less than 20%. It can be applied to environments that require ultra-small space and are not sensitive to cost.

[0038] The combined beam of light emitted from the light outlet of the lower layer structure of the optical multiplexing / demultiplexing component 4 is reflected by the A surface 601 and the B surface 602 in sequence and then converges to the fiber optic adapter 8. The light input by the fiber optic adapter 8 enters the light inlet of the upper layer structure of the optical multiplexing / demultiplexing component 4 after passing through the B surface 602.

[0039] In this embodiment, the receiving optical path is formed by the upper layer structure of the optical multiplexing / demultiplexing component 4 combined with the beam splitting prism 6, and the transmitting optical path is formed by the lower layer structure of the optical multiplexing / demultiplexing component 4 combined with the beam splitting prism 6. While effectively integrating and reducing the number of components, the transmitting optical path and the receiving optical path are effectively separated, effectively avoiding the optical path crosstalk between transmission and reception.

[0040] In this embodiment, the BOX housing 1 can be hermetically or non-hermetically packaged.

[0041] On the rear side surface of the upper layer structure of the optical multiplexing / demultiplexing component 4, light outlets corresponding to the receiving detectors 2 one by one are arranged at intervals in the left-right direction, and a first filter 41 is installed at each light outlet; on the rear side surface of the lower layer structure of the optical multiplexing / demultiplexing component 4, light inlets corresponding to the transmitting lasers 3 one by one are arranged at intervals in the left-right direction, and a second filter 42 is installed at each light inlet.

[0042] In this embodiment, the filter can be fixed to the light outlet of the upper layer structure or the light inlet of the lower layer structure of the optical multiplexing / demultiplexing component 4 by bonding, which has high reliability, saves space and production costs.

[0043] As Figure 6 shown, the light inlet on the front side surface of the upper layer structure of the optical multiplexing / demultiplexing component 4 and the light outlet on the front side surface of the lower layer structure are arranged vertically one above the other in the same vertical plane. A first transmission film 44 and a second transmission film 46 are respectively installed at the light inlet and the light outlet; a first reflection film 43 is arranged on the front side surface of the optical multiplexing / demultiplexing component 4 on the side of the first transmission film 44. The beam splitting part of the upper layer structure of the optical multiplexing / demultiplexing component 4 is formed by the first transmission film 44 and the first reflection film 43 matching the first filter 41; a second reflection film 45 is arranged on the front side surface of the optical multiplexing / demultiplexing component 4 on the side of the second transmission film 46. The light combining part of the lower layer structure of the optical multiplexing / demultiplexing component 4 is formed by the second transmission film 46 and the second reflection film 45 matching the second filter 42.

[0044] In this embodiment, the light emitted by the three emitting lasers 3 is combined into a collimated light beam through the light combining part of the lower layer structure of the beam combining and splitting component 4, and then finally converges to the fiber optic adapter 8 through the reflection of the beam splitting prism 6; while the light input from the fiber optic adapter 8 passes through the beam splitting prism 6 and is split into three light beams through the beam splitting part of the upper layer structure of the beam combining and splitting component 4, and finally received by the three receiving detectors 2.

[0045] During use, the light beam emitted by the emitting laser 3 corresponding to the position of the second transmission film 46 enters the lower layer structure of the beam combining and splitting component 4 after passing through the second filter 42, and then exits the light outlet of the lower layer structure through the second transmission film 46; while the light beams emitted by the other two emitting lasers 3 corresponding to the positions of the second reflection films 45 enter the lower layer structure of the beam combining and splitting component 4 after passing through the corresponding second filters 42 respectively, and then are reflected by the adjacent second filters 42 and second reflection films 45 and exit the light outlet of the lower layer structure through the second transmission film 46; thus, the three light beams emitted by the three emitting lasers 3 are combined into one light beam by the light combining part of the beam combining and splitting component 4. The beam splitting principle of the beam splitting part of the beam combining and splitting component 4 is similar to the above-mentioned light combining principle, but opposite in the path.

[0046] In this embodiment, through the layout of the beam combining and splitting component 4, the light combining part and the beam splitting part are ingeniously integrated and arranged in an upper and lower double-layer structure. Compared with the existing optical devices in which the beam combiner / beam combining component and the beam splitter / beam splitting component are arranged in the horizontal plane, although the size is slightly increased in the thickness direction, it greatly reduces the horizontal occupied area. And compared with the existing optical devices in which the beam combiner / beam combining component and the beam splitter / beam splitting component are arranged in layers in the vertical direction, the size in the thickness direction is also greatly reduced.

[0047] A first lens 20 is respectively arranged between each first filter 41 and the receiving detector 2; a second lens 30 is respectively arranged between each second filter 42 and the emitting laser 3.

[0048] In this embodiment, through the layout of the lenses, the optical path is collimated into a collimated light beam.

[0049] An isolator 5 is arranged between the light outlet of the lower layer structure of the beam combining and splitting component 4 and the B surface 602 of the beam splitting prism 6.

[0050] In this embodiment, the isolator 5 is arranged outside the light outlet of the lower layer structure of the beam combining and splitting component 4. The three light beams emitted by the emitting lasers 3 are combined into a collimated light beam through the light combining part of the beam combining and splitting component 4, and the three emitting lasers 3 share one isolator 5.

[0051] A window 11 is opened on the front side door of the BOX housing 1 in front of the A surface 601 of the beam splitting prism 6, and a ferrule end lens 7 is installed at the window 11; the fiber optic adapter 8 is arranged facing the ferrule end lens 7.

[0052] In this embodiment, the converging light emitted from the fiber optic adapter 8 is collimated into parallel light by the ferrule end lens 7, and then passes through the beam splitting prism 6 and is split into three beams of light by the beam splitting part of the upper structure of the beam combining and splitting component 4.

[0053] The fiber optic adapter 8 is welded and installed on the outer side surface at the window 11 of the BOX housing 1.

[0054] In this embodiment, by welding and installing the fiber optic adapter 8 at the window 11 of the BOX housing 1, a single-fiber triple-transmit and triple-receive optical device encapsulated by a single BOX is formed.

[0055] The A surface 601 and the B surface 602 are arranged at 45°. The B surface 602 reflects and deflects the horizontal light in the front and back directions emitted from the light outlet of the lower structure of the beam combining and splitting component 4 by 90° to convert it into vertical light in the up and down directions, and then the A surface 601 reflects and deflects the vertical light by 90° to convert it into horizontal light in the front and back directions, realizing the transmitting optical path from the transmitting laser 3 to the fiber optic adapter 8; the light input from the fiber optic adapter 8 passes through the A surface 601 and enters the light inlet of the upper structure of the beam combining and splitting component 4, realizing the receiving optical path from the fiber optic adapter 8 to the receiving detector 2.

[0056] As Figure 7 shown, the beam splitting prism 6 includes a prism two 62, a prism one 61, and a prism three 63 that are sequentially attached and arranged from top to bottom. The joint surface between the prism one 61 and the prism two 62 forms the A surface 601, and the joint surface between the prism one 61 and the prism three 63 forms the B surface 602; the rear side surface of the prism one 61 is the C surface 611, and the rear side surface of the prism two 62 is the D surface 621. The C surface 611 and the D surface 621 are arranged in parallel, and the D surface 621 intersects with the A surface 601 and is arranged at a 45° angle.

[0057] For the beam splitting prism 6 located in the transmitting optical path, the light combined by the beam combining and splitting component 4 is incident on the C surface 611, and then is reflected by the B surface 602 and the A surface 601 in sequence and then emitted to the fiber optic adapter 8; for the beam splitting prism 6 located in the receiving optical path, the light input from the fiber optic adapter 8 passes through the A surface 601 and then passes out from the D surface 621 and is incident on the light inlet of the upper structure of the beam combining and splitting component 4.

[0058] In actual operation, in order to prevent reflection, the beam splitting prism 6 is placed slightly inclined, so that the C surface 611 as the incident surface is inclined by 1-8° relative to the combined beam on the basis of perpendicular incidence.

[0059] The beam splitting prism 6 is supported and installed on the inner bottom surface of the BOX housing 1 through the bottom surface of the prism three 63, and the structural stability of the beam splitting prism 6 in the BOX housing 1 is effectively ensured through the prism three 63.

[0060] In actual use, the single-fiber three-transmitter and three-receiver optical device of this embodiment can meet the requirements of 50G PON triple-mode transmission. For example, during the upgrade and transition stage from 2.5G or 10G PON to 50G PON, the wavelengths of the transmitting lasers and receiving detectors can correspond to the communication wavelengths of 2.5G, 10G, and 50G PON respectively. For example, the wavelengths matched by the three transmitting lasers can be 1342nm, 1577nm, and 1490nm respectively, and the wavelengths matched by the three receiving detectors can be 1286nm, 1310nm, and 1270nm respectively.

[0061] The single-fiber three-transmitter and three-receiver optical device of the present utility model effectively reduces the device size through the BOX package with an internal double-layer combined beam splitter component, and can increase the port density by 50%. Moreover, the packaging process is simple and the cost is moderate, which can meet the requirements of 50G PON triple-mode transmission or other application scenarios that require single-fiber three-transmitter and three-receiver.

[0062] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0063] The above description is an explanation of the present utility model, not a limitation thereof. For the scope defined by the present utility model, refer to the claims. Within the protection scope of the present utility model, any form of modification can be made.

Claims

1. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices, characterized in that: The invention comprises a BOX shell (1), wherein a light combining and splitting component (4) is arranged inside the BOX shell (1), and the light combining and splitting component (4) is an integrated structure including an upper and lower double layer, and three groups of receiving detectors (2) are arranged in parallel along the left-right direction at the rear of the upper structure of the light combining and splitting component (4), and a light inlet is provided on the front side of the upper structure; three groups of emitting lasers (3) are arranged in parallel along the left-right direction at the rear of the lower structure of the light combining and splitting component (4), and a light outlet is provided on the front side of the lower structure; a light splitting prism (6) is arranged inside the BOX shell (1) in front of the light combining and splitting component (4), and the light splitting prism (6) comprises an A surface (601) and a B surface (602) arranged in parallel up and down, and an optical fiber adapter (8) is arranged in front of the light splitting prism (6), and the A surface (601) is obliquely located between the light inlet of the upper structure and the optical fiber adapter (8), and the B surface (602) is obliquely located in front of the light outlet of the lower structure.

2. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 1, characterized in that: On the rear side surface of the upper structure of the light combining and splitting component (4), light outlets corresponding to the receiving detectors (2) are arranged at intervals in the left-right direction, and each light outlet is equipped with a filter 1 (41); on the rear side surface of the lower structure of the light combining and splitting component (4), light inlets corresponding to the emitting lasers (3) are arranged at intervals in the left-right direction, and each light inlet is equipped with a filter 2 (42).

3. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 2, characterized in that: The light inlet on the front side of the upper structure of the light combining and splitting component (4) and the light outlet on the front side of the lower structure are arranged up and down and located in the same vertical plane, and a transmission film 1 (44) and a transmission film 2 (46) are respectively arranged at the light inlet and the light outlet; a reflection film 1 (43) is arranged on the front side of the light combining and splitting component (4) located on the side of the transmission film 1 (44), and the light splitting part of the upper structure of the light combining and splitting component (4) is formed by the transmission film 1 (44), the reflection film 1 (43) and the matching filter 1 (41); a reflection film 2 (45) is arranged on the front side of the light combining and splitting component (4) located on the side of the transmission film 2 (46), and the light combining part of the lower structure of the light combining and splitting component (4) is formed by the transmission film 2 (46), the reflection film 2 (45) and the matching filter 2 (42).

4. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 2, characterized in that: A lens one (20) is arranged between each filter one (41) and the receiving detector (2); and a lens two (30) is arranged between each filter two (42) and the transmitting laser (3).

5. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 1, characterized in that: An isolator (5) is arranged between the front of the light outlet of the lower structure of the light combining and splitting component (4) and the B surface (602) of the light splitting prism (6).

6. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 1, characterized in that: A window (11) is provided on the front door of the BOX housing (1) located in front of the A surface (601) of the beam splitter prism (6), and a core end lens (7) is installed at the window (11); the optical fiber adapter (8) is arranged facing the core end lens (7).

7. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 6, characterized in that: The optical fiber adapter (8) is welded to the outer surface of the BOX shell (1) at the window (11).

8. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 1, characterized in that: The A surface (601) and the B surface (602) are arranged at 45 degrees. The B surface (602) reflects and folds the horizontal light in the front-to-back direction emitted from the light outlet of the lower structure of the light combining and splitting component (4) by 90 degrees to convert it into vertical light in the upper direction, and then reflects and folds the vertical light by 90 degrees through the A surface (601) to convert it into horizontal light in the front-to-back direction; the light input by the optical fiber adapter (8) passes through the A surface (601) and then enters the light inlet of the upper structure of the light combining and splitting component (4).

9. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 1, characterized in that: The beam splitter prism (6) comprises a prism 2 (62), a prism 1 (61), and a prism 3 (63) which are sequentially bonded and arranged from top to bottom; the bonding surfaces of the prism 1 (61) and the prism 2 (62) form an A surface (601); the bonding surfaces of the prism 1 (61) and the prism 3 (63) form a B surface (602); the rear side surface of the prism 1 (61) is a C surface (611); the rear side surface of the prism 2 (62) is a D surface (621); the C surface (611) and the D surface (621) are arranged in parallel; the D surface (621) intersects with the A surface (601) and is arranged at an angle of 45°.

10. A BOX-packaged single-fiber three-transmitter and three-receiver optical device with built-in double-layer optical combining and splitting devices as claimed in claim 9, characterized in that: The dichroic prism (6) is mounted on the inner bottom surface of the BOX shell (1) via the bottom surface support of prism three (63).

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