Visible light fiber optic rotary connector and calibration method

Abstract

The present invention belongs to the technical field of optical fiber rotary connectors. Provided is a visible light optical fiber rotary connector and calibration method, through a slotted ferrule with a flange end cap with an observation window, a main shaft with a calibration window, and an observation slot on the slotted ferrule, the distance between the end faces of two optical fibers can be controlled, thereby realizing the calibration of the insertion loss of the entire system; the rotating optical fiber and the stationary optical fiber in the observation slot of the calibration ferrule are observed under a microscope, the position of the calibration ferrule in the main shaft is adjusted, the light transmission efficiency of the optical power meter and the spectrum change of the spectrometer are observed in real time, and when the light transmission efficiency and the spectrum change reach the optimal effect, the main shaft is heated to solidify the epoxy resin, and the debugging is completed, thereby improving the efficiency of calibration and debugging.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber rotary connectors, and in particular to a visible light optical fiber rotary connector and a calibration method. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] Optical fiber communication has high bandwidth, large capacity, simple structure, no spectrum license required and good confidentiality, and is considered a key technology in the fields of industry, medical equipment, etc. Optical fiber rotary connector is an important device that uses optical fiber communication technology to realize the signal transmission function between the stationary platform and the relatively rotating platform. Its principle is that the light beam emitted from the stationary end optical fiber is processed and transmitted to the rotating end, and coupled to the optical fiber to realize optical signal transmission.

[0004] The traditional processing method is to use a fiber collimator. The light beam emitted from the static end of the fiber enters the gradient-index lens (G-Lens) for collimation to become a spatially collimated light beam, which is then transmitted to the gradient-index lens at the rotating end and coupled into the optical fiber to achieve optical signal transmission. The traditional processing method has the following problems: (1) It is difficult to debug. The optical axis of the collimator and the rotation axis of the mechanical part need to be highly overlapped, otherwise it will cause large insertion loss and light transmission efficiency fluctuations; (2) The speed limit is large. The volume of the entire system is large and high-speed rotation cannot be achieved (some current applications require a speed of more than 10,000 revolutions per minute); (3) Dispersion control is difficult, especially in the field of visible light OCT. The wider spectrum requires that there should not be too high chromatic aberration in the system. For these reasons, it becomes difficult to design a fiber optic rotary connector based on a collimator, and an achromatic double cemented lens is required, which is very expensive.

[0005] In recent years, lensless fiber optic rotary connector technology for high bandwidth has emerged. It uses two optical fibers to align directly, resulting in lower optical loss at the contact point. However, this technology still has some problems: (1) Compared with conventional infrared optical fibers, optical fibers in the visible light band have thinner cores and smaller mode field diameters, only 2~3μm, while the diameter of the optical fiber cladding is usually several hundred microns. This places very high demands on the position error (radial deviation) of the fiber optic rotary connector, which cannot be achieved with existing technology; (2) To maintain low insertion loss, the distance between the end faces of the two bare optical fibers (axial deviation) cannot be too large. If they are too close or even in contact, the end faces of the optical fibers will be worn, thereby causing damage to the device; in addition, it is difficult to observe, and the assembly of the optical fiber can only be evaluated by indirectly testing the light transmission efficiency. The overall assembly efficiency and assembly accuracy are not high. Summary of the invention

[0006] In order to solve the deficiencies of the prior art, the present invention provides a visible light fiber optic rotary connector and a calibration method, which improve the convenience of debugging while ensuring low insertion loss.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a visible light fiber optic rotary connector.

[0009] A visible light optical fiber rotary connector, comprising: a first male connector, a flange, a flange end cap, a slotted ferrule, a calibration ferrule, a main shaft with a calibration window, a synchronous wheel, a rotary bearing, a female connector, and a second male connector;

[0010] The slotted ferrule is inserted into the flange end cap, and the stationary optical fiber passes through the first male connector and the flange in sequence, and then enters the slotted ferrule in the flange end cap with the observation window;

[0011] The rotating optical fiber enters from the female connector, passes through the second male connector and enters the main shaft. The outer wall of the main shaft is connected with a synchronous wheel. The main shaft is connected to the inner ring of the rotating bearing and passes through the inner ring. The main shaft can rotate under the drive of the synchronous wheel. The rotating optical fiber is fixed in the main shaft by a calibration ferrule.

[0012] The bare connector of the rotating optical fiber passing through the calibration ferrule enters into the slotted ferrule, and an observation slot is provided on the slotted ferrule. The meeting point of the bare connector of the rotating optical fiber and the bare connector of the stationary optical fiber is located within the observation field of the observation window and the observation slot.

[0013] As a further limitation of the first aspect of the present invention, the first male connector, the flange and the flange end cap are all fixed in the stationary end cap, the first male connector is connected to one end of the flange, and the other end of the flange is connected to one end of the flange end cap;

[0014] The slotted insert is inserted into the center of the flange end cap from the other end of the flange end cap, and the other end of the flange end cap is axially fixedly connected with the side plate through screws.

[0015] As a further limitation of the first aspect of the present invention, the outer ring of the bearing is fixed in the rotating bearing seat, a part of the slotted core and the screw are inserted into the rotating bearing seat, and the side plate is located in the rotating bearing seat.

[0016] As a further limitation of the first aspect of the present invention, the rotary bearing is two angular contact ball bearings placed back to back, and one end of the rotary bearing is fixed in the rotary bearing seat by a bearing fixing ring.

[0017] As a further limitation of the first aspect of the present invention, a rotating end cap is connected to the end of the rotating bearing seat, and the main shaft enters the bearing in the rotating bearing seat from the rotating end cap.

[0018] As a further limitation of the first aspect of the present invention, the second male connector is connected to the rotating flange, and a portion of the second male connector that passes through the rotating flange is connected to the main shaft via a coupling.

[0019] As a further limitation of the first aspect of the present invention, a through hole with an inner diameter of 2.5 mm is opened on the main shaft along the direction of the central axis, and the inner diameter of the calibration insert is 250 μm.

[0020] As a further limitation of the first aspect of the present invention, the processing depth of the observation groove is 1.2 mm and the processing width is 1 mm.

[0021] As a further limitation of the first aspect of the present invention, the calibration ferrule is a ceramic ferrule.

[0022] In a second aspect, the present invention provides a method for calibrating a visible light fiber optic rotary connector.

[0023] A method for calibrating a visible light optical fiber rotary connector, used for the visible light optical fiber rotary connector according to the first aspect of the present invention, comprises the following steps:

[0024] The rotating optical fiber in the calibration ferrule is fixed by UV-curing glue, and the outer surface of the calibration ferrule is coated with epoxy resin and then inserted into the through hole of the main shaft;

[0025] The stationary optical fiber is connected to the light source, and the rotating optical fiber is connected to the optical power meter and the spectrometer respectively;

[0026] Observe the rotating optical fiber and the stationary optical fiber in the observation slot of the calibration ferrule under a microscope, adjust the position of the calibration ferrule in the spindle, and observe the light transmission efficiency of the optical power meter and the spectrum changes of the spectrometer in real time;

[0027] When the light transmission efficiency and spectrum change reach the optimal effect, heat the main shaft to solidify the epoxy resin and complete the debugging.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention innovatively proposes a visible light fiber optic rotary connector, which can control the distance between the end faces of two optical fibers through a slotted ferrule with a flange end cap with an observation window, a main shaft with a calibration window, and an observation slot on the slotted ferrule, thereby realizing the calibration of the insertion loss of the entire system.

[0030] 2. The present invention innovatively proposes a calibration method for a visible light fiber optic rotary connector. The rotating optical fiber and the stationary optical fiber in the observation slot of the calibration ferrule are observed under a microscope, the position of the calibration ferrule in the main shaft is adjusted, and the light transmission efficiency of the optical power meter and the spectral changes of the spectrometer are observed in real time. When the light transmission efficiency and the spectral changes reach the optimal effect, the main shaft is heated to solidify the epoxy resin, and the debugging is completed, thereby improving the efficiency of calibration and debugging.

[0031] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 A schematic diagram of the overall appearance of a visible light optical fiber rotary connector including a jumper provided by the present invention;

[0034] Figure 2 A schematic diagram of the appearance of the main part of the visible light optical fiber rotary connector provided by the present invention;

[0035] Figure 3 A detailed schematic diagram of the main body of the visible light optical fiber rotary connector provided by the present invention;

[0036] Figure 4 A schematic diagram of a slotted ferrule provided by the present invention;

[0037] Figure 5 A schematic diagram of a flange end cap provided by the present invention;

[0038] Figure 6 A schematic diagram of the main shaft provided by the present invention;

[0039] Among them, 1. stationary end cap; 2. rotating bearing seat; 3. synchronous wheel; 4. coupling; 5. first male connector; 6. female connector; 7. jumper wire; 8. main shaft; 9. calibration insert; 10. slotted insert; 11. screw; 12. flange end cap; 13. flange; 14. second male connector; 15. rotating end cap; 16. angular contact ball bearing; 17. rotating flange; 18. bearing fixing ring; 19. side plate. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0042] In this implementation, a visible light fiber optic rotary connector is proposed, which can achieve very low insertion loss and is easy to debug. Figure 1 , Figure 2 and Figure 3 As shown, it includes: a first male connector 5 (preferably an FC male connector), a flange 13 (preferably an FC flange), a flange end cap 12 (preferably an FC flange), Figure 5 As shown), slotted ferrule 10 (as Figure 4 As shown), calibration insert 9, spindle 8 with calibration window (as shown Figure 6 As shown), a synchronous wheel 3, a rotary bearing, a female connector 6 (preferably an SC female connector) and a second male connector 14 (preferably an FC male connector);

[0043] The slotted ferrule 10 is inserted into the flange end cap 12, and the stationary optical fiber passes through the first male connector 5 and the flange 13 in sequence, and then enters the slotted ferrule 10 in the flange end cap 12 with the observation window;

[0044] The rotating optical fiber enters from the female connector 6, passes through the second male connector 14 and enters the main shaft 8. The outer wall of the main shaft 8 is connected with a synchronous wheel 3. The main shaft 8 is connected to the inner ring of the rotating bearing and passes through the inner ring. The main shaft 8 can rotate under the drive of the synchronous wheel 3. The rotating optical fiber is fixed in the main shaft 8 by the calibration ferrule 9.

[0045] The bare connector of the rotating optical fiber passing through the calibration ferrule 9 enters into the slotted ferrule 10, and the slotted ferrule 10 is provided with an observation groove. The meeting point of the bare connector of the rotating optical fiber and the bare connector of the stationary optical fiber is located within the observation field of the observation window and the observation groove.

[0046] In this implementation, preferably, the first male connector 5, the flange 13 and the flange end cap 12 are all fixed in the stationary end cap 1, the first male connector 5 is connected to one end of the flange 13, and the other end of the flange 13 is connected to one end of the flange end cap 12;

[0047] The slotted ferrule 10 is inserted into the center of the flange end cap 12 from the other end thereof, and the other end of the flange end cap 12 is axially fixedly connected to the side plate 19 by means of screws 11; the outer ring of the bearing is fixed in the rotating bearing seat 2, a part of the slotted ferrule 10 and the screws 11 are inserted into the rotating bearing seat 2, and the side plate 19 is located in the rotating bearing seat 2. More specifically, the stationary optical fiber enters from the jumper 7, passes through the first male connector 5 and the flange 13 in sequence, and enters the slotted ferrule 10 with a diameter of 2.5 mm (the slotted ferrule 10 is inserted in the flange end cap 12 with an observation window).

[0048] In this implementation, when the first male connector 5 and the second male connector 14 adopt FC male connectors, the full name of FC is Ferrule Connector, which is an optical fiber connector that is externally reinforced with a metal sleeve and fastened with a screw buckle; the first male connector 5 and the second male connector 14 in this implementation can both use the PC (Physical Connection) method to grind the cross-section of the optical fiber connector.

[0049] In this implementation, when the female connector 6 adopts an SC female connector, the full name of SC is Subscriber Connector, which is a standard connector type widely used in optical fiber communication systems; the female connector 6 in this implementation can adopt the APC (Angled Physical Contact Connector) method to grind the cross-section of the optical fiber connector.

[0050] In the present implementation, preferably, the rotary bearings are two angular contact ball bearings 16 placed back to back, and one end of the rotary bearing is fixed in the rotary bearing seat 2 via a bearing fixing ring 18 .

[0051] In this implementation, preferably, a rotating end cap 15 is connected to the end of the rotating bearing seat 2, and the main shaft 8 enters the bearing in the rotating bearing seat 2 from the rotating end cap 15.

[0052] In this implementation, preferably, the second male connector 14 is connected to the rotating flange 17 , and the portion of the second male connector 14 that passes through the rotating flange 17 is connected to the main shaft 8 through the coupling 4 .

[0053] In this implementation, preferably, Figure 6 As shown, the spindle 8 is provided with a through hole with an inner diameter of 2.5 mm along the center axis, and calibration windows are provided at the upper and lower parts of the spindle 8 .

[0054] In this implementation, preferably, the inner diameter of the calibration ferrule 9 is 250 μm (preferably a ceramic ferrule is used), the calibration ferrule 9 is used to fix the rotating optical fiber, the rotating optical fiber is in a coating state (diameter 250 μm) when it is on the right side of the calibration ferrule 9 and inside the calibration ferrule 9, and on the left side of the calibration ferrule 9 is a bare optical fiber with the coating removed and only a 125 μm cladding (corresponding to the bare connector of the rotating optical fiber), the bare connector of the rotating optical fiber is directly inserted into the slotted ferrule 10 of the static part on the left, the bare connector of the rotating optical fiber and the bare connector of the static optical fiber meet in the slotted ferrule 10, and the meeting point can be observed in the 1 mm observation groove of the slotted ferrule 10. Through tools such as a microscope, through the observation window on the observation groove and the flange end cap 12, and then through the calibration window opened on the main shaft 8, the end face distance of the bare connector of the rotating optical fiber and the bare connector of the static optical fiber can be controlled, thereby realizing the calibration of the insertion loss of the entire system.

[0055] In this implementation, preferably, Figure 4 As shown, the slotted ferrule 10 is 22 mm long, 2.5 mm in outer diameter, 126 μm in inner diameter, with V holes at both ends (the V holes can easily insert 250 μm optical fibers), an observation groove in the middle, a processing depth of 1.2 mm, and a processing width of 1 mm (a small portion of the optical fiber can be seen exposed, rather than half of the optical fiber being exposed).

[0056] Based on the above-mentioned visible light fiber optic rotary connector, this implementation also proposes a calibration method for the visible light fiber optic rotary connector, including the following process:

[0057] Step (1): The optical fiber in the calibration ferrule 9 is fixed by UV-curing glue, and epoxy resin is applied to the outer surface of the calibration ferrule 9 and then inserted into the hole of the main shaft 8;

[0058] Step (2): The stationary optical fiber is connected to the light source, and the rotating optical fiber is connected to the optical power meter and the spectrometer respectively;

[0059] Step (3): Observe the conditions of the two optical fibers in the ceramic ferrule slot under a microscope, use tweezers or other tools to adjust the position of the calibration ferrule 9 in the main shaft 8, and observe the light transmission efficiency of the optical power meter and the spectrum changes of the spectrometer in real time;

[0060] Step (4): When the effect is optimal (i.e., both the light transmission efficiency and the spectrum change reach the optimal value), the main shaft 8 is heated to solidify the epoxy resin, and the debugging is completed.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A visible light optical fiber rotary connector, It is characterized in that It includes: a first male connector, a flange, a flange end cap, a slotted insert, a calibration insert, a main shaft with a calibration window, a synchronous wheel, a rotary bearing, a female connector and a second male connector; The slotted ferrule is inserted into the flange end cap, and the stationary optical fiber passes through the first male connector and the flange in sequence, and then enters the slotted ferrule in the flange end cap with the observation window; The rotating optical fiber enters from the female connector, passes through the second male connector and enters the main shaft. The outer wall of the main shaft is connected with a synchronous wheel. The main shaft is connected to the inner ring of the rotating bearing and passes through the inner ring. The main shaft can rotate under the drive of the synchronous wheel. The rotating optical fiber is fixed in the main shaft by a calibration ferrule. The bare connector of the rotating optical fiber passing through the calibration ferrule enters into the slotted ferrule, the slotted ferrule is provided with an observation slot, and the meeting point of the bare connector of the rotating optical fiber and the bare connector of the stationary optical fiber is located within the observation field of the observation window and the observation slot; Through the microscope through the observation slot and the observation window on the flange end cap, and then through the calibration window opened on the main shaft, the end face distance of the bare connector of the rotating optical fiber and the bare connector of the stationary optical fiber is controlled to achieve the calibration of the insertion loss; The outer diameter of the slotted ferrule is 2.5mm, the processing depth of the observation slot is 1.2mm, and the processing width is 1mm. A small part of the optical fiber can be seen exposed, rather than half of the optical fiber; A through hole with an inner diameter of 2.5 mm is opened along the central axis of the spindle, and calibration windows are opened on the upper and lower parts of the spindle; The calibration method of the visible light optical fiber rotary connector comprises: The rotating optical fiber in the calibration ferrule is fixed by UV-curing glue, and the outer surface of the calibration ferrule is coated with epoxy resin and then inserted into the through hole of the main shaft; The stationary optical fiber is connected to the light source, and the rotating optical fiber is connected to the optical power meter and the spectrometer respectively; Observe the rotating optical fiber and the stationary optical fiber in the observation slot of the calibration ferrule under a microscope, adjust the position of the calibration ferrule in the spindle, and observe the light transmission efficiency of the optical power meter and the spectrum changes of the spectrometer in real time; When the light transmission efficiency and spectrum change reach the optimal effect, heat the main shaft to solidify the epoxy resin and complete the debugging.

2. The visible light optical fiber rotary connector according to claim 1, characterized in that: The first male connector, the flange and the flange end cap are all fixed in the stationary end cap, the first male connector is connected to one end of the flange, and the other end of the flange is connected to one end of the flange end cap; The slotted insert is inserted into the center of the flange end cap from the other end of the flange end cap, and the other end of the flange end cap is axially fixedly connected with the side plate through screws.

3. The visible light optical fiber rotary connector according to claim 2, characterized in that: The outer ring of the bearing is fixed in the rotating bearing seat, a part of the slotted insert and the screw are inserted into the rotating bearing seat, and the side plate is located in the rotating bearing seat.

4. The visible light optical fiber rotary connector according to claim 3, characterized in that: The rotary bearing is two angular contact ball bearings placed back to back, and one end of the rotary bearing is fixed in the rotary bearing seat through a bearing fixing ring.

5. The visible light optical fiber rotary connector according to claim 3, characterized in that: The end of the rotating bearing seat is connected with a rotating end cap, and the main shaft enters the bearing in the rotating bearing seat from the rotating end cap.

6. The visible light optical fiber rotary connector according to any one of claims 1 to 5, characterized in that: The second male joint is connected to the rotating flange, and a portion of the second male joint passing through the rotating flange is connected to the main shaft through a coupling.

7. The visible light optical fiber rotary connector according to any one of claims 1 to 5, characterized in that: The inner diameter of the calibration ferrule is 250 μm.

8. The visible light optical fiber rotary connector according to any one of claims 1 to 5, characterized in that: The calibration ferrule is a ceramic ferrule.

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