High return loss coaxial expanded beam contact

Abstract

The present invention relates to the field of optical fiber communication technology, and discloses a high return loss coaxial beam expansion contact, including a ceramic sleeve, a beam expansion lens, a glass slide, and an optical fiber pin. The front end face of the optical fiber pin is a first inclined plane; the rear end face of the glass slide is a second inclined plane with the same inclination angle as the first inclined plane, so that the rear end face of the glass slide and the front end face of the optical fiber pin are adapted and fixed at an angle, and the angle of the outgoing light emitted from the front end face of the optical fiber pin is corrected and the first stage of beam expansion is performed; the front end face of the glass slide is a plane, and the rear end face of the beam expansion lens facing the glass slide is a vertical plane, which receives the light beam after the angle correction and the first stage of beam expansion by the glass slide, and after the second stage of beam expansion, emits the parallel light beam after the second stage of beam expansion from the front end face of the beam expansion lens. The high return loss coaxial beam expansion contact of the present invention has the characteristics of low loss, high return loss, good interchangeability, strong stain resistance, and stable connection, and can be integrated into a variety of optical fiber and optoelectronic composite connector applications such as circular / rectangular / neutral.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication, and in particular to a high return loss coaxial beam expansion contact. Background Art

[0002] As the transmission capacity of optical fiber communication systems continues to increase, single-channel 25Gbps optical modules have begun to be used. At the same time, with the rapid development of analog optical transmission systems, more and more communication systems use optical fibers to transmit analog signals such as clocks and radio frequencies, which places higher requirements on the insertion loss and return loss of optical fiber connectors.

[0003] Traditional physical contact fiber optic connectors are very sensitive to dirt and dust, because the fiber end face is exposed to the air during assembly or use. Whether it is environmental factors or human factors, the fiber end face may be contaminated. The optical fiber light transmission area is very small. If dust of a few microns or tens of microns appears on the fiber docking end face, it will block the light signal and even damage the optical interface. In an environment with frequent shock and vibration, the fiber end face of the physical contact type connector is constantly rubbed or even collided, which will cause damage to the fiber end face, which may increase the insertion loss or even fail to connect. Compared with the contact type fiber optic connector, the beam expansion type fiber optic connector uses the beam expansion lens added to the front end of the optical fiber to expand the light transmission area and collimate the light beam, thereby reducing the impact of longitudinal deviation and realizing non-contact transmission. It has the characteristics of environmental resistance, anti-pollution, stable connection, etc., and is more suitable for field communications and emergency communications in dusty environments.

[0004] Traditional coaxial fiber beam expansion contacts adopt an optical-mechanical coaxial design. For example, a Chinese patent with publication number CN218547056U provides a self-focusing lens beam expansion contact composed of a sleeve, a fiber optic pin and a self-focusing lens. The self-focusing lens is inserted from the front end of the sleeve, and the fiber optic pin is inserted from the rear end of the sleeve. The front end face of the fiber optic pin and the rear end face of the self-focusing lens are spaced apart in the front-to-back direction, and the focus of the self-focusing lens is located at the front end face of the fiber optic pin. As shown in the accompanying drawings, by setting the end faces of the pin and the lens as inclined planes, the light beam is deflected through the inclined plane to improve the return loss performance. However, the outgoing light beam and the outgoing end face form a small angle, and calibration is required for installation in the connector. The product interchangeability is poor, and the insertion loss performance of the product after being installed in the connector is difficult to guarantee. Summary of the invention

[0005] In view of the defects and shortcomings of the prior art, the present invention aims to provide a high return loss coaxial beam expansion fiber contact, in which a glass slide for correcting the inclination of the light beam is designed between the fiber pin and the self-focusing lens, and the front end face of the fiber pin of the beam expansion contact is designed as a bevel, and a glass slide with the same inclination angle is used to correct the angle of the optical fiber output light, so as to ensure that the two contacts have good coaxiality, interchangeability and high return loss when docked, and realize the primary amplification of the light beam; at the same time, the other end face of the glass slide is designed as a vertical plane, and the rear end face of the self-focusing lens is also designed as a vertical plane, so that the processing accuracy and assembly of the input surface of the self-focusing lens and the output surface of the glass slide are more precise, so as to realize more precise secondary beam expansion and amplification, so that the diameter of the beam expansion spot is far beyond the dust size, and the influence of pollutants such as dust is reduced.

[0006] According to a first aspect of the present invention, a high return loss coaxial beam expansion optical fiber contact is provided, comprising a ceramic sleeve, a beam expansion lens, a glass sheet and an optical fiber pin coaxially arranged in the ceramic sleeve; the glass sheet is located between the beam expansion lens and the optical fiber pin;

[0007] The front end surface of the optical fiber pin is set as a first inclined surface;

[0008] The rear end face of the glass slide is set as a second inclined surface with the same inclination angle as the first inclined surface, so that the rear end face of the glass slide and the front end face of the optical fiber pin are adapted at an angle and fixed to form a whole, and the angle of the outgoing light emitted from the front end face of the optical fiber pin is corrected and the first stage of beam expansion is performed;

[0009] The front end surface of the glass slide is set as a vertical plane, serving as an exit surface of the light beam after the first stage of beam expansion;

[0010] The rear end face of the beam expander lens facing the glass slide is used as the incident surface and is set as a vertical plane to receive the light beam after angle correction and primary beam expansion through the glass slide, and after the secondary beam expansion, emit the parallel light beam after the secondary beam expansion from the front end face of the beam expander lens.

[0011] As an optional embodiment, the diameter of the glass slide is larger than the diameter of the expanded beam spot formed by the parallel light beam after secondary beam expansion, and smaller than the inner diameter of the ceramic sleeve.

[0012] As an optional embodiment, the sum of the lengths of the air gaps formed between the glass slide and the beam expander lens is set to an optical length of (0.25±0.02)P, where the parameter P represents the intercept.

[0013] As an optional embodiment, the rear end face of the glass slide is fixed to the front end face of the optical fiber pin via a glue having a matching refractive index.

[0014] As an optional embodiment, the beam expander lens is a cylindrical G-Lens lens or a C-Lens lens, and the surface shape of one end close to the glass slide is set to be a plane.

[0015] As an optional embodiment, the outer cylindrical surface of the beam expander lens is frosted and fixed to the inside of the ceramic sleeve using UV heated dual-curing glue on the outer cylindrical surface.

[0016] As an optional embodiment, the beam expander lens is fixed to the inside of the ceramic sleeve using UV heated dual-curing glue.

[0017] As an optional embodiment, the ceramic sleeve is fixedly sleeved on the outer surface of the optical fiber pin using UV heating dual-curing glue.

[0018] As an optional embodiment, the inner and outer cylindrical surfaces at both ends of the ceramic sleeve are provided with rounded corner structures.

[0019] As an optional embodiment, the inclination angle between the first inclined plane and the second inclined plane is 8°±. 0.5°.

[0020] In the high return loss coaxial beam expansion contact of each embodiment of the present invention, the front end face of the optical fiber pin of the beam expansion contact is set as a bevel, and a glass slide with the same inclination angle is used to correct the angle of the optical fiber output light, so as to ensure that the two contacts have good coaxiality, interchangeability and return loss performance when docked. At the same time, the glass slide and the beam expansion lens are used to achieve secondary amplification of the light spot, so that the diameter of the beam expansion spot is far beyond the dust size, reducing and eliminating the influence of pollutants such as dust. UV heating dual-curing glue is used to fix the beam expansion lens to the ceramic sleeve and the ceramic sleeve to the optical fiber pin, which can quickly complete the pre-curing of the glue, effectively avoiding the pollution of the optical end face of the product during the curing process of a single thermal curing glue or the problem of insufficient bonding strength of a single UV glue.

[0021] The high return loss coaxial expanded beam contact proposed in the present invention has the characteristics of low loss, high return loss, good interchangeability, strong pollution resistance and stable connection. It can be integrated into a variety of circular / rectangular / neutral optical fiber and optoelectronic composite connectors, and is suitable for applications with relatively stringent requirements such as large capacity, high strength and high temperature resistance.

[0022] In combination with the embodiments of the above aspects, compared with the prior art, the high return loss coaxial expanded beam contact of the present invention has the following significant advantages:

[0023] 1. High return loss and good interchangeability. In the existing designs, the return loss of optical fiber contacts has been improved by optical coating. The return loss of single-mode beam expansion contacts only meets ≥30dB, and the return loss of multi-mode beam expansion contacts only meets ≥20dB. However, the high return loss coaxial beam expansion contacts proposed in the present invention can improve the return loss of single-mode beam expansion contacts to ≥50dB, and the return loss of multi-mode beam expansion contacts to ≥35dB. At the same time, the glass slides with the same tilt angle are used to correct the angle of the optical fiber output light, and the amplified light spot is concentrated at the center of the beam expansion contact, which can ensure that the two contacts have good coaxiality and interchangeability when docking.

[0024] 2. Strong dirt resistance; the high return loss coaxial beam expansion contact of the present invention adopts a glass slide and a beam expansion lens to achieve secondary amplification of the light spot, and can expand the diameter of the light spot of a single-mode optical fiber from 9um to 220um, which is far beyond the dust size (0.2-20um);

[0025] 3. High production efficiency and good reliability. The expansion lens of the high return loss coaxial expansion contact of the present invention is fixed to the ceramic sleeve by UV heating dual-curing glue, which can timely and effectively pre-cure the bonding glue, avoid contamination of the lens end face during the glue bonding process, reduce the cleaning time of the lens end face, improve production efficiency, and perform secondary curing by heating to ensure the reliability of product bonding.

[0026] The outer cylindrical surface of the beam expander lens is set to be frosted, which can effectively ensure the amount of glue between the beam expander lens and the ceramic sleeve, increase the bonding force, and make the bonding between the beam expander lens and the ceramic sleeve firm and reliable, with a bonding force of more than 70N;

[0027] 4. Low cost: The high return loss coaxial beam expansion contact of the present invention achieves high return loss without the need for traditional optical coating methods, thus saving production time and manufacturing costs;

[0028] 5. The high return loss coaxial beam expansion contact of the present invention has an outer diameter and installation positioning dimensions that meet the requirements of the Arinc801 standard, and can be easily integrated on a variety of optical fiber and optoelectronic composite connectors such as circular / rectangular / neutral.

[0029] It should be understood that all combinations of the aforementioned concepts and the additional concepts described in more detail below can be considered as part of the inventive subject matter of the present disclosure as long as such concepts are not mutually inconsistent. In addition, all combinations of the claimed subject matter are considered as part of the inventive subject matter of the present disclosure.

[0030] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in each figure may be represented by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0032] Figure 1 It is a structural diagram of the first self-focusing optical fiber beam expansion contact according to the prior art.

[0033] Figure 2 It is a structural diagram of a second self-focusing optical fiber beam expansion contact according to the prior art.

[0034] Figure 3 4 is a schematic structural diagram of a high return loss coaxial beam expansion optical fiber contact according to an embodiment of the present invention.

[0035] Figure 4 4 is a three-dimensional diagram of a glass slide of a high return loss coaxial expanded beam optical fiber contact according to an embodiment of the present invention.

[0036] Figure 5 FIG. 4 is a side view of a glass slide of a high return loss coaxial expanded beam optical fiber contact according to an embodiment of the present invention.

[0037] Figure 6 Schematic diagram of a fiber optic pin of a high return loss coaxial beam expansion fiber optic contact according to an embodiment of the present invention.

[0038] Figure 7 FIG. 4 is a side view of a beam expander lens of a high return loss coaxial beam expander optical fiber contact according to an embodiment of the present invention.

[0039] Figure 8 Schematic diagram of a fiber optic pin tail tube of a high return loss coaxial beam expansion fiber optic contact according to an embodiment of the present invention.

[0040] Fig. 9 It is a principle diagram of optical path transmission of a high return loss coaxial beam expansion optical fiber contact in a docking state according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0042] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. In addition, some aspects disclosed by the present invention can be used alone or in any appropriate combination with other aspects disclosed by the present invention.

[0043] {Example 1}

[0044] Combination Figure 3 to Figure 9 As shown, the high return loss coaxial beam expansion contact according to the embodiment of the present invention comprises a ceramic sleeve 10, a beam expansion lens 11, a glass sheet 12 and an optical fiber pin 13 coaxially arranged in the ceramic sleeve 10. The glass sheet 12 is located between the beam expansion lens 11 and the optical fiber pin 13.

[0045] Combination Figure 3 , Figure 6 As shown, the front end surface of the optical fiber pin 13 is set as a first inclined surface. Figure 4 , Figure 5 As shown, the rear end surface 12B of the glass slide 12 is set to have the same inclination angle as the first inclined surface. β The second inclined surface makes the rear end face of the glass slide 12 and the front end face of the optical fiber pin 13 form an angle adaptation and fixation, and the angle of the outgoing light emitted from the front end face of the optical fiber pin 13 is corrected and the first stage of beam expansion is performed.

[0046] Combination Figure 3 , Figure 5 , Fig. 9 As shown, the front end face 12A of the glass slide 12 is set as a vertical plane, which serves as the exit face of the light beam after the first stage of beam expansion. The rear end face of the beam expander lens 11 facing the glass slide 12 is used as the incident face, which is set as a vertical plane, receives the light beam after angle correction and first stage of beam expansion through the glass slide 12, and emits a parallel light beam after second stage of beam expansion from the front end face of the beam expander lens 11 after second stage of beam expansion.

[0047] Thus, through the cooperation between the optical fiber pin and the glass slide, the front end face of the optical fiber pin 13 is an inclined surface, which improves the return loss of the beam expansion contact, and the rear end face 12B of the glass slide adopts the same tilt angle to match, and the angle of the optical fiber output light is corrected in advance by the glass slide with the same tilt angle. Fig. 9 As shown, the enlarged light spot is concentrated at the center of the beam expansion contact, which can ensure good coaxiality and interchangeability when the two contacts are docked;

[0048] Therefore, by designing the bevel matching between the optical fiber pin and the glass slide, the return loss of the beam expansion contact, the beam correction and the first-stage beam expansion effect can be achieved at the same time.

[0049] Furthermore, through the cooperation between the glass slide and the beam expander lens, the front end face of the glass slide is a vertical plane, and the rear end face of the beam expander lens 11 is also a vertical plane. The light beam after the first beam expansion by the glass slide enters the beam expander lens vertically, and the second stage beam expansion is performed on the vertically incident light beam to achieve the second stage amplification of the light spot, so that the size of the beam expansion light spot is far beyond the dust size, and the anti-fouling ability is improved. The diameter of the light spot of the single-mode optical fiber 9um can be expanded to 220um, which is far beyond the dust size (0.2-20um).

[0050] As an optional embodiment, the diameter of the glass slide 12 is larger than the diameter of the expanded beam spot formed by the parallel light beam after the secondary beam expansion, and smaller than the inner diameter of the ceramic sleeve 10. Thus, it is ensured that the light beam completely passes through the glass slide 12, avoiding the loss caused by the edge of the light beam contacting the edge of the glass slide or exceeding the range of the glass slide, and facilitating the installation of the glass slide in the ceramic sleeve.

[0051] As an optional embodiment, the sum of the lengths of the air gaps formed between the glass slide 12 and the beam expander lens 11 is set to an optical length of (0.25±0.02)P, where the parameter P represents the intercept. Thus, by precisely controlling the length of the air gap, it can be ensured that the light emitted from the optical fiber pin can be approximately horizontal after passing through the glass slide and the beam expander lens, ensuring that the beam quality after beam expansion is good and the spot shape is regular.

[0052] As an optional embodiment, the inclination angle between the first bevel and the second bevel is 8°±0.5°, which can not only achieve a higher return loss, but also reduce the processing and grinding time to ensure efficiency.

[0053] Preferably, the rear end face of the glass slide 12 is fixed to the front end face of the optical fiber pin 13 via a glue 18 with a matching refractive index to form a fixed whole, so as to reduce the docking loss during the optical path transmission process.

[0054] As an optional embodiment, combining Figure 7 As shown, the beam expander lens 11 may be a cylindrical G-Lens lens or a C-Lens lens, and the surface of one end (i.e., the rear end surface 11B) close to the glass slide 12 is set to be a plane. The front end surface 11A of the beam expander lens 11 is an exit surface.

[0055] In a particularly preferred embodiment, the outer cylindrical surface of the beam expander lens 11 is frosted, and is fixed to the inside of the ceramic sleeve 10 using UV heated dual-curing glue on the outer cylindrical surface. Thus, the amount of glue between the beam expander lens and the ceramic sleeve can be effectively guaranteed, so that the bonding between the beam expander lens and the ceramic sleeve is firm and reliable.

[0056] As an optional embodiment, the beam expander lens 11 is fixed to the inside of the ceramic sleeve 10 by using UV heating dual-curing glue. The ceramic sleeve 10 is fixedly sleeved on the outer surface of the optical fiber pin 13 by using UV heating dual-curing glue.

[0057] Therefore, UV heated dual-curing glue is used to fix the beam expander lens and the ceramic sleeve, which can pre-cure the bonding glue in a timely and effective manner, avoid contamination of the lens end face during the glue bonding process, reduce the cleaning time of the end face of the beam expander lens, and improve production efficiency. At the same time, secondary curing is performed by heating to ensure the reliability of product bonding.

[0058] In an optional embodiment, the ceramic sleeve 10 is fixed to the optical fiber pin 13 with UV heated dual-curing glue, and the dual-curing glue is pre-cured with a UV lamp on the optical coupling platform. This can effectively prevent the glue from flowing to the end face of the glass slide or the beam expander lens, affecting the optical performance of the product, thereby improving the first-time qualified rate of the product.

[0059] Combination Figure 3 In the illustrated embodiment, the high return loss coaxial beam expansion contact of the present invention further includes a fiber optic pin tail tube 14 , a spring 15 , an outer shell 16 and a crimping sleeve 17 .

[0060] The tail of the optical fiber pin 13 is fixed to the front end of the optical fiber pin tail handle 14 by interference fit. Figure 3 As shown, the exposed length of the ceramic sleeve 10 relative to the optical fiber pin tail handle 14 is relatively short, and can be better integrated into various optical fiber and optoelectronic connectors.

[0061] As an optional embodiment, the inner and outer cylindrical surfaces at both ends of the ceramic sleeve 10 are provided with rounded corners to ensure smooth insertion and removal of the optical fiber contact after being installed in the connector. The ceramic sleeve 10 can be designed as a closed form to provide sufficient docking strength for the contact when docking.

[0062] Combination Figure 3 , Figure 8 As shown, the front opening of the optical fiber ferrule tail handle 14 is provided with a flaring structure 14A, which facilitates one end of the ceramic sleeve 10 to smoothly enter the front groove of the optical fiber ferrule tail handle 14. An angled structure 14B is provided at the upper end of the convex key of the optical fiber ferrule tail handle 14 to ensure operability when the outer shell is closed with a closing tool.

[0063] {Example 3}

[0064] Combination Figure 3 to Figure 9 As shown, the high return loss coaxial expanded beam contact sample according to the embodiment of the present invention was tested and compared with the coaxial expanded beam contact of traditional design, and the test results are shown in Tables 1 and 2 below.

[0065] Table 1 - Return loss test comparison in multimode transmission mode

[0066]

[0067] Table 2 - Return loss test comparison in single-mode transmission mode

[0068]

[0069] From the above test comparison, it can be seen that according to the high return loss coaxial expanded beam contact designed according to the present invention, the return loss of the single-mode expanded beam contact can be increased to ≥50dB, and the return loss of the multi-mode expanded beam contact can be increased to ≥35dB. Compared with the expanded beam contacts of traditional design, the return loss performance is significantly improved, and it has the advantages of coaxiality, good interchangeability, strong pollution resistance and stable connection.

[0070] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A high return loss coaxial expanded beam contact, characterized in that: It comprises a ceramic sleeve (10), and a beam expander lens (11), a glass sheet (12), and an optical fiber plug pin (13) which are coaxially arranged in the ceramic sleeve (10); the glass sheet (12) is located between the beam expander lens (11) and the optical fiber plug pin (13); The front end surface of the optical fiber pin (13) is configured as a first inclined surface; The rear end face (12B) of the glass slide (12) is arranged as a second inclined surface having the same inclination angle as the first inclined surface, so that the rear end face of the glass slide (12) and the front end face of the optical fiber plug pin (13) are adapted at an angle and fixed to form an integral body, and the angle of the outgoing light emitted from the front end face of the optical fiber plug pin (13) is corrected and the first stage of beam expansion is performed; The front end surface (12A) of the glass slide (12) is set as a vertical plane, serving as an exit surface of the light beam after the first stage of beam expansion; The rear end face of the beam expanding lens (11) facing the glass slide (12) is used as an incident face and is arranged as a vertical plane, receives the light beam after angle correction and primary beam expansion through the glass slide (12), performs secondary beam expansion, and emits a parallel light beam after secondary beam expansion from the front end face of the beam expanding lens (11); The diameter of the glass slide (12) is larger than the diameter of the beam expansion spot formed by the parallel light beam after secondary beam expansion, and smaller than the inner diameter of the ceramic sleeve (10).

2. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The sum of the lengths of the air gap formed between the glass slide (12) and the beam expanding lens (11) is set to an optical length of (0.25±0.02)P, where the parameter P represents the intercept.

3. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The rear end face (12B) of the glass slide (12) is fixed to the front end face of the optical fiber pin (13) via a refractive index matching glue (18).

4. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The beam expansion lens (11) is a cylindrical G-Lens lens or a C-Lens lens, and the surface shape of one end close to the glass slide (12) is set to be a plane.

5. The high return loss coaxial expanded beam contact according to claim 4, characterized in that: The outer cylindrical surface of the beam expanding lens (11) is frosted and fixed to the inside of the ceramic sleeve (10) using UV heated dual-curing glue on the outer cylindrical surface.

6. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The beam expanding lens (11) is fixed inside the ceramic sleeve (10) using UV heated dual-curing glue.

7. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The ceramic sleeve (10) is fixedly sleeved on the outer surface of the optical fiber pin (13) using UV heated dual-curing glue.

8. The high return loss coaxial expanded beam contact according to claim 1, characterized in that: The inner and outer cylindrical surfaces at both ends of the ceramic sleeve (10) are both provided with rounded corner structures.

9. The high return loss coaxial expanded beam contact according to any one of claims 1 to 8, characterized in that: The inclination angle between the first inclined surface and the second inclined surface is 8°±0.5°.

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