OTDR optical device housing and OTDR optical device
By adopting a beam splitting structure and stray light absorption cavity design, the problems of large size and high cost of traditional OTDR modules are solved, realizing the miniaturization and stability improvement of OTDR optical devices, which are suitable for compact optical modules.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2026-03-06
AI Technical Summary
Traditional OTDR modules are difficult to compress due to the use of circulators, have high costs, and are sensitive to temperature, which limits their application in compact optical modules.
The housing of the OTDR optical device with a beam splitting structure includes a mirror cavity, a beam splitting diaphragm, and a stray light absorption cavity. The beam splitting diaphragm splits the optical signal into target light and stray light. The stray light absorption cavity is equipped with a light-absorbing coating and a reflective slope to absorb stray light and avoid crosstalk.
It enables miniaturization of OTDR optical devices, reduces costs, and improves long-term stability, making it suitable for compact optical modules.
Smart Images
Figure CN223977386U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of optical communication technology, specifically relating to an OTDR optical device housing and an OTDR optical device. Background Technology
[0002] With the rapid development of fiber optic communication networks towards higher speeds and larger capacities, the demand for optical link performance monitoring and fault location is becoming increasingly urgent. OTDR (Optical Time Domain Reflectometer) technology, as a core means of fiber optic line quality assessment, has seen miniaturization and cost reduction of its modules become a key research focus in the industry.
[0003] Traditional OTDR modules employ a circulator architecture based on free-space optics. While this architecture can isolate emitted and reflected light, it suffers from several technical challenges due to the complex three-port non-reciprocal nature of the circulator: First, the circulator requires multiple sets of precision optical components, such as Faraday rotators and polarizing beam splitters, making it difficult to compress the device size. Second, the free-space optical path requires high-precision mechanical alignment, significantly increasing packaging complexity and manufacturing costs. Third, this discrete structure is highly sensitive to temperature, posing challenges to long-term stability and limiting its application in compact optical modules. Utility Model Content
[0004] The purpose of this invention is to overcome the problems in the existing technology where OTDR modules require the use of a circulator, which increases the packaging space and has a high cost.
[0005] To address this, the present invention provides an OTDR optical device housing, comprising a housing body having a mirror cavity; the housing body having a light emission port, a light receiving port, and an adapter port; the mirror cavity having a beam-splitting diaphragm and a stray light absorption cavity; the beam-splitting diaphragm having a transmission surface and a beam-splitting surface; the transmission surface facing the light emission port; the light inlet of the stray light absorption cavity being located on the reflected light path of the transmission surface; the light receiving port being located on the reflected light path of the beam-splitting surface; and the adapter port being located on the transmitted light path of the transmission surface.
[0006] Specifically, the inner wall of the aforementioned stray light absorption cavity is provided with a light-absorbing coating.
[0007] Specifically, the stray light absorption cavity is provided with a reflective inclined surface; the reflective inclined surface is located on the incident light path of the stray light absorption cavity.
[0008] Specifically, the shell body has an opening that communicates with the stray light absorption cavity; a sealing cover is provided at the opening; and the reflective slope is provided on the side of the sealing cover facing the stray light absorption cavity.
[0009] Specifically, a beam-splitting diaphragm support is provided inside the aforementioned mirror cavity; the beam-splitting diaphragm is mounted on the beam-splitting diaphragm support.
[0010] This utility model also provides an OTDR optical device, including an optical emitting module, an optical receiving module, an adapter, and the aforementioned OTDR optical device housing; the optical emitting module, the optical receiving module, and the adapter are respectively installed on the optical emitting port, the optical receiving port, and the adapter port of the housing body.
[0011] Specifically, an isolator is provided in the optical path between the aforementioned light emitting module and the beam splitting diaphragm.
[0012] Specifically, an optical fiber lens is provided in the optical path between the adapter and the beam splitter.
[0013] Specifically, the aforementioned OTDR optical device also includes an adjustment ring; the optical emission module is coupled and fixed to the optical emission port through the adjustment ring.
[0014] Specifically, the pin assembly of the aforementioned adapter is coupled and fixed to the adapter port; the coupling end face angle of the pin assembly is 8°.
[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0016] The OTDR optical device housing provided by this invention eliminates the need for a circulator and employs a beam-splitting structure, significantly reducing production costs while ensuring the performance of both the emitted and reflected optical paths. The housing itself contains a stray light absorption cavity that absorbs stray light from the TX beam reflected by the beam-splitting diaphragm, preventing crosstalk to other TX TO and RX TO beams. Based on this OTDR optical device housing, the resulting OTDR optical device is smaller, lower in cost, and more manufacturable, providing a reliable technical path for integrating OTDR diagnostic functions into next-generation miniaturized pluggable optical modules.
[0017] The present invention will be further described in detail below with reference to the accompanying drawings. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the housing structure of an OTDR optical device in one implementation method.
[0019] Figure 2 This is a schematic diagram of the spectrophotometer structure in one implementation method.
[0020] Figure 3 This is a schematic diagram of the sealing cover structure in one implementation method.
[0021] Figure 4 This is a cross-sectional view of the sealing cover plate in one implementation method.
[0022] Figure 5This is a schematic diagram of the structure of an OTDR optical device in one implementation method.
[0023] Figure 6 This is an optical path diagram of an OTDR optical device in one implementation method.
[0024] Figure 7 This is a schematic diagram of the near-end reflection optical path of an OTDR optical device in one implementation method.
[0025] Figure 8 This is a schematic diagram of the stray light absorption cavity of an OTDR optical device absorbing TX TO in one implementation method.
[0026] Explanation of reference numerals in the attached drawings: 1. Housing body; 101. Optical transmitting port; 102. Optical receiving port; 103. Adapter port; 2. Beam splitting diaphragm; 201. Transmitting surface; 202. Beam splitting surface; 3. Beam splitting diaphragm support; 4. Stray light absorption cavity; 5. Light-absorbing coating; 6. Reflective bevel; 7. Sealing cover; 8. Boss; 9. Optical transmitting module; 901. TX base; 902. TX end cap; 903. Laser chip; 10. Adjustment ring; 11. Isolator; 12. Optical receiving module; 121. RX base; 122. RX end cap; 123. Detector chip; 13. Pin assembly; 131. Coupling end face; 14. Fiber optic lens. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0028] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0030] Reference Figure 1-2 This utility model provides an OTDR optical device housing, including a housing body 1 with a mirror cavity; the housing body 1 has a light emission port 101, a light receiving port 102, and an adapter port 103; the mirror cavity is provided with a beam-splitting diaphragm 2 and a stray light absorption cavity 4; the beam-splitting diaphragm 2 is inclined toward the light emission port 101 and includes a transmission surface 201 and a beam-splitting surface 202. The transmission surface 201 allows the target beam to pass through smoothly, and the beam-splitting surface 202 can split a beam of light into reflected light and transmitted light; the transmission surface 201 faces the light emission port 101; the light inlet of the stray light absorption cavity 4 is located on the reflected light path of the transmission surface 201; the light receiving port 102 is located on the reflected light path of the beam-splitting surface 202; and the adapter port 103 is located on the transmitted light path of the transmission surface 201. Light incident from the light emission port 101 is split into two beams by the transmission surface 201 of the beam splitter 2. One beam is the target beam, which propagates through the beam splitter 2 and then through the adapter port 103. The other beam is stray light, which is reflected and absorbed in the stray light absorption cavity 4. The optical signal transmitted from the adapter port 103 reaches the beam splitter 2, where the beam splitting surface 202 reflects a portion of the beam to the light receiving port 102, while the other beam passes through the beam splitter 2. The housing body 1 is preferably manufactured using powder metallurgy molding, which can further reduce costs.
[0031] Specifically, a light-absorbing coating 5 is provided on the inner wall of the stray light absorption cavity 4. The light-absorbing coating 5 is preferably formed by coating the inner wall with black glue.
[0032] Furthermore, a reflective slope 6 is provided within the stray light absorption cavity 4; the reflective slope 6 is located on the incident light path of the stray light absorption cavity 4. Preferably, a light-absorbing coating 5 is also provided on the reflective slope 6 to absorb stray light. (Refer to...) Figure 8 The reflective ramp 6 prevents stray light from returning to its original optical path and reflects it to the inner wall of the stray light absorption cavity 4, absorbing the stray light multiple times, thus improving the absorption effect and reducing the damage caused by stray light to the laser's interior. The tilt angle of the reflective ramp 6 is generally 15-20°, but can be arranged according to actual conditions to ensure that the reflected light does not pass through the light inlet of the stray light absorption cavity 4. During assembly, a light-absorbing coating 5 can also be applied to the reflective ramp 6.
[0033] In a more detailed embodiment, the shell body 1 has an opening communicating with the stray light absorption cavity 4, preferably located on the surface opposite to the light inlet of the stray light absorption cavity 4 and parallel to the plane of the light inlet. A sealing cover plate 7 is provided at the opening; the reflective inclined surface 6 is provided on the side of the sealing cover plate 7 facing the stray light absorption cavity 4.
[0034] Specifically, such as Figure 3-4 As shown, the sealing cover 7 has a boss 8 on the side facing the stray light absorption cavity 4; the outer diameter of the boss 8 matches the inner diameter of the stray light absorption cavity 4, and it can be inserted into the stray light absorption cavity 4. The reflective bevel 6 is provided on the surface of the boss 8 and is arranged opposite to the light inlet. The sealing cover 7 and the boss 8 are preferably made of metal.
[0035] Furthermore, a beam-splitting diaphragm support 3 is provided inside the mirror cavity; the beam-splitting diaphragm 2 is mounted on the beam-splitting diaphragm support 3.
[0036] Reference Figure 5 This utility model also provides an OTDR optical device, including an optical emitting module 9, an optical receiving module 12, an adapter, and the aforementioned OTDR optical device housing; the optical emitting module 9, the optical receiving module 12, and the adapter are respectively installed on the optical emitting port 101, the optical receiving port 102, and the adapter port 103 of the housing body 1. In use, the optical path references... Figure 6 The optical signal emitted by the optical emitting module 9 is split into two beams by the beam splitter 2. One beam is coupled into the pin assembly 13 of the adapter and propagates, while the other beam is reflected by the beam splitter 2 and absorbed by the stray light absorption cavity 4. The optical signal transmitted from the adapter enters the mirror cavity through the pin assembly 13 and reaches the beam splitter 2. The beam splitter 2 reflects a portion of the beam to the optical receiving module 12, converting the optical signal into an electrical signal, while the other beam passes through the beam splitter 2.
[0037] In one embodiment, the optical emitting module 9 is a TX TO, including a TX base 901, a TX end cap 902, and a laser chip 903 (LD chip). The laser chip 903 is mounted on the TX base 901 and encapsulated by the TX end cap 902, which has a first lens. After the laser chip 903 converts an electrical signal into an optical signal and emits it, the large-aperture optical signal is shaped into a small-angle beam by the first lens on the TX end cap 902 and enters the mirror cavity.
[0038] The optical receiver module 12 is preferably RX TO, including an RX base 121, an RX end cap 122, and a detector chip 123 (PD chip). The detector chip 123 is mounted on the RX base 121 and encapsulated by the RX end cap 122, which has a second lens. The detector chip 123 can be an APD & TIA chip. The optical signal transmitted from the remote end reaches the beam splitter 2 through the ferrule assembly 13. The beam splitter 2 reflects a portion of the beam to the RX end cap 122, where it is focused by the second lens onto the detector chip 123, converting the optical signal into an electrical signal.
[0039] Furthermore, an isolator 11 is provided in the optical path between the optical emitting module 9 and the beam splitter 2. The light emitted by the optical emitting module 9 is split into two beams by the beam splitter 2 after passing through the isolator 11. The optical signal transmitted from the adapter end enters the mirror cavity through the pin assembly 13 and reaches the beam splitter 2. The beam splitter 2 reflects a portion of the beam into the optical receiving module 12, while the other beam passes through the beam splitter 2 and reaches the isolator 11.
[0040] In one embodiment, a fiber lens 14 is provided in the optical path between the adapter and the beam splitter 2. The incident light emitted by the optical emitting module 9 is split into two beams by the beam splitter 2. One beam is coupled to the pin assembly 13 of the adapter through the fiber lens 14 and propagates, while the other beam is reflected by the diaphragm and absorbed by the stray light absorption cavity 4. The optical signal transmitted from the remote end passes through the pin assembly 13 and the fiber lens 14 and reaches the beam splitter 2. The beam splitter 2 reflects a portion of the beam to the optical receiving module 12, while the other beam is transmitted through the beam splitter 2.
[0041] Specifically, a lens holder is installed inside the mirror cavity to mount the fiber optic lens 14.
[0042] In one embodiment, the OTDR optical device further includes an adjustment ring 10; the optical emitting module 9 is coupled and fixed to the optical emitting port 101 via the adjustment ring 10. The adjustment ring 10 is used to adjust the structured optical path matching to ensure the stability of the optical device.
[0043] In one embodiment, the adapter's pin assembly 13 is coupled and fixed to the adapter port 103; the coupling end face 131 of the pin assembly 13 has an angle of 8°. (Refer to...) Figure 7 As shown, this can reduce near-end reflection crosstalk from TX to RX.
[0044] Example 1:
[0045] This embodiment provides an OTDR optical device housing, including a housing body 1 with a mirror cavity; the housing body 1 is provided with a light emission port 101, a light receiving port 102, and an adapter port 103; the mirror cavity is provided with a beam splitting diaphragm support 3 and a stray light absorption cavity 4.
[0046] A beam-splitting diaphragm 2 is attached to the beam-splitting diaphragm support 3. The beam-splitting diaphragm 2 includes a transmission surface 201 and a beam-splitting surface 202. The transmission surface 201 allows the target beam to pass through smoothly, and the beam-splitting surface 202 can split a beam of light into 40% reflected light and 60% transmitted light. The transmission surface 201 faces the light emission port 101.
[0047] The light inlet of the stray light absorption cavity 4 is located on the reflected light path of the transmission surface 201; the light receiving port 102 is located on the reflected light path of the beam splitting surface 202; and the adapter port 103 is located on the transmitted light path of the transmission surface 201.
[0048] The inner wall of the stray light absorption cavity 4 is coated with black glue to form a light-absorbing coating 5. An opening communicating with the stray light absorption cavity 4 is provided on the shell body 1, located on the surface opposite to the light inlet of the stray light absorption cavity 4 and parallel to the plane of the light inlet. A sealing cover 7 is provided at the opening; a boss 8 is provided on the side of the sealing cover 7 facing the stray light absorption cavity 4; the outer diameter of the boss 8 matches the inner diameter of the stray light absorption cavity 4 and can be inserted into the stray light absorption cavity 4; the surface of the boss 8 is a reflective slope 6, arranged opposite to the light inlet, and the reflective slope 6 is coated with black glue to form a light-absorbing coating 5. The sealing cover 7, the boss 8, and the shell body 1 are made of metal.
[0049] This embodiment also provides an OTDR optical device, including an optical transmitting module 9, an optical receiving module 12, an adapter, and the aforementioned OTDR optical device housing;
[0050] The optical emitting module 9 is a TX TO, including a TX base 901, a TX end cap 902, and a laser chip 903; the laser chip 903 is mounted on the TX base 901 and encapsulated by the TX end cap 902, and the TX end cap 902 is provided with a first lens;
[0051] The optical receiver module 12 is RX TO, including RX base 121, RX end cap 122, and detector chip 123; the detector chip 123 is mounted on the RX base 121 and encapsulated by the RX end cap 122, and the RX end cap 122 is provided with a second lens.
[0052] The optical emitting module 9 is installed on the optical emitting port 101 of the housing body 1 via the adjusting ring 10, the optical receiving module 12 is installed on the optical receiving port 102 of the housing body 1, and the adapter pin assembly 13 is coupled and installed on the adapter port 103. The coupling end face 131 of the pin assembly 13 has an angle of 8°.
[0053] An isolator 11 is provided in the optical path between the optical emission module 9 and the beam splitting diaphragm 2;
[0054] A fiber optic lens 14 is provided in the optical path between the adapter and the beam splitter 2.
[0055] The above-mentioned OTDR optical devices are assembled using the following steps:
[0056] The first step is to use traditional coaxial device packaging technology to seal and solder both TX TO and RX TO to provide hermetically sealed protection for the laser chip 903 and the detector chip 123.
[0057] The second step is to sequentially attach the isolator 11, fiber optic lens 14, and beam splitter 2 to the housing body 1 using 353ND glue and then bake them.
[0058] The third step is to perform four-piece coupling on the pin assembly 13, the adjusting ring 10, the TX TO, and the housing body 1, and to couple them to the maximum value. First, the pin assembly 13 is lap-welded to the housing body 1, and then the TX TO is recoupled. First, the TX TO and the adjusting ring 10 are pierced and welded, and then the housing body 1 and the adjusting ring 10 are lap-welded.
[0059] The fourth step is to couple RX TO to the shell body 1. After coupling to the maximum value, apply adhesive and cure.
[0060] Step 5, sealing the cover plate 7 and reinforcing with glue: Apply black glue to the inclined surface of the sealing cover plate 7 and the stray light absorption cavity 4 respectively, then assemble them together and bake; add black glue reinforcement at RX TO.
[0061] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.
Claims
1. An OTDR optical device housing, characterized by: The OTDR optical device shell comprises a shell body (1) with a mirror cavity; a light emitting port (101), a light receiving port (102) and an adapter port (103) are formed on the shell body (1); a light splitting diaphragm (2) and a stray light absorption cavity (4) are arranged in the mirror cavity; the light splitting diaphragm (2) comprises a transmission surface (201) and a light splitting surface (202); the transmission surface (201) faces the light emitting port (101); the light entrance of the stray light absorption cavity (4) is located on the reflection light path of the transmission surface (201); the light receiving port (102) is located on the reflection light path of the light splitting surface (202); the adapter port (103) is located on the transmission light path of the transmission surface (201).
2. The OTDR optical device housing of claim 1, wherein: An inner wall of the stray light absorption cavity (4) is provided with a light absorption coating (5).
3. The OTDR optical device housing of claim 1, wherein: The stray light absorption cavity (4) is provided with a reflection inclined surface (6); the reflection inclined surface (6) is located on the incident light path of the stray light absorption cavity (4).
4. The OTDR optical device housing of claim 3, wherein: An opening is formed on the shell body (1) and communicates with the stray light absorption cavity (4); a sealing cover plate (7) is arranged at the opening; the reflection inclined surface (6) is arranged on the side of the sealing cover plate (7) facing the stray light absorption cavity (4).
5. The OTDR optical device housing as described in claim 1, characterized in that: The mirror cavity is provided with a light splitting diaphragm support (3); the light splitting diaphragm (2) is mounted on the light splitting diaphragm support (3).
6. An OTDR optical device, characterized by: The OTDR optical device shell comprises a light emitting module (9), a light receiving module (12), an adapter and the shell body of any one of claims 1-5; the light emitting module (9), the light receiving module (12) and the adapter are respectively mounted on the light emitting port (101), the light receiving port (102) and the adapter port (103) of the shell body (1).
7. The OTDR optical device of claim 6, wherein: An isolator (11) is arranged on the light path between the light emitting module (9) and the light splitting diaphragm (2).
8. The OTDR optical device of claim 6, wherein: An optical fiber lens (14) is arranged on the light path between the adapter and the light splitting diaphragm (2).
9. The OTDR optical device of claim 6, wherein: An adjusting ring (10) is further arranged; the light emitting module (9) is coupled and fixed to the light emitting port (101) through the adjusting ring (10).
10. The OTDR optical device of claim 6, wherein: A pin assembly (13) of the adapter is coupled and fixed to the adapter port (103); the coupling end surface (131) of the pin assembly (13) has an angle of 8°.