WO2012113941A1

WO2012113941A1 - Device for connecting two optical components that can be at least partially slid into one another

Info

Publication number: WO2012113941A1
Application number: PCT/EP2012/053287
Authority: WO
Inventors: Steffen Böhme; Gerd Harnisch; Michael VOM HEEDE; Dirk Walter BOGS; Volker Gustav WIRTH
Original assignee: Limo Patentverwaltung Gmbh & Co. Kg
Priority date: 2011-02-25
Filing date: 2012-02-27
Publication date: 2012-08-30

Abstract

The invention relates to a device for connecting two optical components that can be at least partially slid into one another, wherein the first component is a ferrule (3), for example, and has a cylindrical section, and wherein the device comprises clamping means, in particular a clamping sleeve (5), which can exert a force on the cylindrical section of the first of the two components in the radial direction.

Description

"Device for the connection of two at least partially telescoping, optical components"

The present invention relates to a device for the connection of two at least partially telescoping, optical components according to the preamble of claim 1.

Frequently in a laser system, the beam source and the optical processing (process head, pump medium, ...) are spatially separated from each other. The optical merging of the two parts is usually done by optical fibers, which are connected to each other via a plug-screw method.

Depending on the beam parameters of the source, the

the laser power used and the necessary protective mechanisms derived therefrom (e.g., stray light, temperature, breakage sensor, etc.), the development of fiber connectors and the like has occurred. for the

Automotive industry for laser welding of body parts with kW lasers. These plugs are expensive to manufacture and

accordingly expensive. In the power range up to some 100 W optical laser power often comes the partially standardized

Fiber connector SMA 905 is used. This is the case

Fiber guiding element, the ferrule, often made of a good

thermally conductive alloy to the incorrectly coupled laser radiation to convert heat and ensure good heat dissipation of the absorbed laser energy through the plug-socket connection. Part of the misdirected laser radiation thereby also reaches the cladding of the optical fiber and, if not properly disposed of, can damage or destroy the subsequent fiber coating and thereby also the fiber connector. Highly accurate, cost-effective fiber plug solutions for single-mode applications are known from the telecommunications sector, but they do not withstand high laser powers with in some cases moderate beam quality of the source, due in part to the use of plastics. For this reason, numerous

Plug solutions designed for higher laser powers, which usually consist of temperature-resistant and wear-resistant alloys and / or ceramics. Patent US 005179610 describes a detachable fiber plug connection with a socket, which dissipates misdirected radiation via a second transmission path, partially reflects it and dissipates it via absorption to housing parts. This approach requires many extremely accurate parts, the tolerances of which directly affect the efficiency of disposing of misdirected radiation. Also both ferrule and socket (counterpart) are subject to tolerances. Furthermore, part of the ferrule guide length is sacrificed for the lateral window openings, which can additionally reduce the positional stability of the fiber connector. A reproducible Faserstecker- socket connection with a lateral positional deviation of <1μιη is not

reachable.

Applying a similar approach misdirected laser radiation through a second transmission path with integrated or adjoining diffusion elements and then on absorption in the

Dispose of fiber connector, pursuing the patent WO 2005/040863 A2. However, here too, the numerous are closely tolerated

Components such as e.g. Diffusers with inner and outer diameter, the efficiency of the disposed radiation fixed. Due to the large number of tolerance-bearing parts is a centering error between inner

Fiber hole drilling and ferrule Au ßendurchmesser in the range of <1μιη unlikely and only insufficiently reproducible and thus hardly suitable for a mass product. Also is the fiber connector due to its low heat capacity and the missing

Thermal connection to a heat sink unable to absorb a power loss in the range of 5W. The case

resulting temperatures in and on the fiber plug can then lead to burns of the user when touching and gradual degradation of the fiber cable.

With increasing power density and the use of different

Laser sources (laser diode, fiber laser, etc.) with different beam quality also result in new requirements for the

Transport of the laser power via flexible, detachable fiber plug cables. The fiber connectors used contain as precisely manufactured ferrules for the lateral positioning of the optical fiber, the high performance of good thermal conductivity, wear-resistant

Alloys are made. A lossless coupling to the

Laser source can be achieved only to a limited extent due to manufacturing tolerances, in particular the ferrule, moderate beam quality and / or optical aberrations in the beam path.

One approach is to functionally separate the positional accuracy of the fiber in the ferrule from its desired, good one

Thermal conductivity and a holistic approach to the tolerancing of ferrule and bush (counterpart). The production of high-precision ferrules of Zr0 ₂ is mastered. The use of these ferrules in fiber connectors for low laser powers is in

Telecommunications area widely used. The concentricity error between fiber hole and ZrO2 ferrule Au ßendurchmesser is less than 1μιη. With the free-standing fiber end (this is already the EP 0704728 A2, in which inter alia a free-standing fiber end is described) within the ferrule is a laser material processing of the ferrule by the high power density in focus at a non-optimal coupling, eg by a moderate Beam quality, avoided. At the same time, the fiber end is adjusted and fixed in an axially highly reproducible manner relative to the ferrule end surface. No adhesive is applied in the immediate area of the fiber connector.

The problem underlying the present invention is to provide a device of the type mentioned, which allows a precise and reproducible positioning of the two components to each other.

This is inventively achieved by a device of the type mentioned above with the characterizing features of claim 1. The subclaims relate to preferred embodiments of the invention.

According to claim 1 it is provided that the device comprises clamping means which can exert a force on the cylindrical portion of the first of the two components in the radial direction. By such clamping means can be a precise mounting of a

cylindrical portion of a first component in a portion of a second component can be ensured.

The device may include embodiments for clamping

Sliding sleeves, ferrules, rods or other axially symmetric components include that should be held either laterally and / or axially very accurately.

With the device can be, for example, lateral

To reach accuracies in the range of 0.1 to 5 μιη. Axial position accuracies can be achieved in the range from 0.01 ° to 0.5 °. The development of a play-free ferrule-socket connection creates a highly accurate, detachable fiber connector without

Losses due to manufacturing tolerances, which is also suitable for high optical performance. Nevertheless meets a part of the laser radiation only the cladding of the fiber, this portion is absorbed by the roughened mantle surface radially diffused to the fiber axis over the good heat conducting connector housing before the beginning of the fiber coating. The plug housing serves as a thermal bridge to the housing of the radiation source. Sufficient cooling of the laser source e.g. by a Peltier element or water is often already there

available to achieve a power and wavelength stable laser operation. Thus, the presented fiber connector has a similar dimension as a conventional SMA 905 connector with a significantly improved centering error and the potential for

Disposal of optical power loss of at least 5W.

Due to the functional separation of the required high

Positional accuracy of the optical fiber of the previously used high ferrule thermal conductivity can also be recovered

High precision ferrules made of ZrO ₂ with poorer properties

Use thermal conductivity for high laser powers. If the position of the fiber in the ferrule also remains in the counterpart of the socket, the coupling losses for a detachable fiber connector connection are minimized. Both the fiber connector with integrated thermal bridge and the position-preserving socket are followed by a few variants.

The presented approach with its variants is applicable for lasers in cw as well as in pulse mode. Other features and advantages of the present invention will become more apparent from the following description

Embodiments with reference to the accompanying

Illustrations. Show in it

Fig. 1 is a schematic perspective view of a first

Component of a device according to the invention;

Fig. 2 is a schematic perspective view of a second

Component of a device according to the invention;

3 shows schematically a first operating principle of the clamping means;

4 shows schematically a second operating principle of the clamping means;

5 shows a section through a first embodiment of a

Clamping sleeve of a device according to the invention;

Fig. 6 is a section through a second embodiment of a

Clamping sleeve of a device according to the invention;

Fig. 7 is a section through a fiber connector a

device according to the invention;

8 shows a section through a connection of the fiber connector according to FIG. 7 with a socket of a device according to the invention;

Fig. 9 is a schematic sectional view of an inventive

Contraption;

Fig. 10 is a schematic sectional view of the device according to

Fig. 9 with a first embodiment of clamping means; Fig. 11 is a schematic sectional view of the device according to

Fig. 9 with a second embodiment of clamping means.

In the figures, identical or functionally identical parts are provided with the same reference numerals. Fig. 1 shows a first optical component, which is designed as a fiber connector 1. On the end of the optical fiber 2, a ferrule 3 is applied, which has a cylindrical outer contour.

However, there is also the possibility that the first component is a sliding sleeve, a ferrule, or a rod or another axially symmetrical component, or that the first component comprises a sliding sleeve, a ferrule, or a rod or another axially symmetrical component ,

Fig. 2 shows a second optical component, which is designed as a fiber connector socket 4, for example, to a laser light source

is arranged. The fiber connector socket 4 has a cylindrical cavity with a clamping sleeve 5 arranged therein serving as a clamping means and having a receptacle 6. The ferrule 3 can be inserted into the receptacle 6 of the clamping sleeve 5 for producing the connection between the first and second component. In particular, such a clamping sleeve 5 on the one hand ensure precise positioning in the lateral or radial direction. For example, lateral

Position accuracies in the range of 0.1 to 5 μιη can be achieved.

On the other hand, such a clamping sleeve a precise

Ensure alignment of the ferrule 3 and the fiber end held by this to the fiber connector socket 4. For example, you can while directional accuracies in the range of 0.01 ° to 0.5 ° can be achieved.

3 and 4 illustrate that the ferrule 3 can be held in the receptacle 6 by radial forces 7, 8, 9, which press the ferrule 3 against one or more sections 10, 11, 12 of the inside of the clamping sleeve 5.

Figures 3 and 4 illustrate a precise lateral clamping in a fixed reference socket of the socket. It is irrelevant whether the lateral clamping pressure is uniform from several sides or only one side, as shown in the sketch. The design of the pan as an exact impression of the plug or only as a 2-point support is not crucial. Important is the precise lateral

Guiding and clamping a precisely cylindrical shape, which may be a precision ferrule of a fiber connector or a precision sleeve of a laser diode.

Fig. 5 shows a first embodiment of a clamping sleeve 5. As the dimensions of 2,983.61 μιη and 2,991.80 μιη can be removed, deviates the cross section of the receptacle 6 in the percentage range of the circular shape. The receptacle 6 is followed on the right side of FIG. 5 a

Gap 13 which extends over more than about 210 ° circumferentially spaced from the perimeter of the receptacle 6 around it. In this way, two result, at least partially in

Circumferentially extending, in the radial direction through the

Interspace 13 spaced sections 14, 15 of the clamping sleeve. 5

When the ferrule 3 is inserted into the receptacle 6, it is outside with a large portion of their Au on the inner portion fourteenth on, which is slightly resilient due to the adjoining him outside the gap 13 and can exert a radially inwardly directed force on the ferrule 3.

Fig. 6 shows a second embodiment of a clamping sleeve 5, the receptacle 6 also has a slightly different from the circular cross-section. Fig. 6 shows that the right third (120 ° circumferential) of the receptacle 6 has a first inner abutment surface 16 which has a radius of 1.253 μι. Furthermore, FIG. 6 shows that the left two-thirds (240 ° circumferential) of the receptacle 6 have a second inner abutment surface 17, which likewise has a radius of 1.253 μm.

However, the center of the radius of the first contact surface 16 is shifted by 50 μm to the left in FIG. 6 relative to the center of the radius of the second contact surface 17. As a result, the receptacle 6 on a clear width, which is slightly smaller than that of a circle with a radius of 1.253 μιη.

At the same time but in the left two-thirds of the clamping sleeve 5 four staggered spaces 18, 19, 20, 21st

provided, which extend from the receptacle 6 only radially outward and then in the circumferential direction. In this way arise six, at least partially extending in the circumferential direction, in the radial direction through the intermediate spaces 18, 19, 20, 21st

When the ferrule 3 is inserted into the receptacle 6, it is ßenseite with a large portion of their Au on the inner portions 22, 23, due to the adjoining them outside Gaps 18, 19, 20, 21 are slightly resilient and can exert a radially inwardly directed force on the ferrule 3.

The embodiment of FIG. 6 has the advantage of a higher rigidity over that according to FIG. 5

Clamping on. Furthermore, the embodiment according to

Fig. 6 has a symmetrical structure, so that when inserting the ferrule 3 torques exert only a small influence.

The inner portions 14, 22, 23 act as a spring element which surrounds the ferrule 3 and receives the lateral position of the ferrule 3. In the embodiment according to FIG. 6, a reinforced clamping action is generated due to the two inner sections 22, 23 acting as spring element. Due to the fixed inner contact surface 16 with respect to the movable spring elements, which is exactly reshaped to the cylindrical surface of the ferrule 3, the position is always optimally maintained (in contrast to a collet, for example). Furthermore

ensures the clamping sleeve 5 by the spring force adaptation to different expansion coefficients of clamping sleeve 5 and ferrule 3 in temperature response.

Fig. 7 shows in detail a fiber connector 1. In the figure, in addition to the ferrule 3 and the optical fiber 2, a Ferrulenaufnahme 28, a partial surrounding this connecting part 29 and a

Protective tube 30 shown, which surrounds the optical fiber 2, which is provided in the course with a coating 31. In one

End region, the optical fiber 2 is exempt from the coating 31, but is up in the connecting part 29 of a sleeve 32nd

surround.

Laser radiation that strikes only the fiber cladding is after the ferrule 3 by a roughened cladding surface on the inner surface of the Ferrule receptacle 28 emitted and absorbed. These jacket modes 33 are also illustrated in FIG. 7.

FIG. 8 shows the connection of the fiber connector 1 according to FIG. 7 with a fiber connector 4 with a clamping sleeve 5 schematically indicated therein. On the left side of FIG. 8 the laser radiation 42 to be coupled into the optical fiber 2 is schematically indicated.

The Ferrulenaufnahme 28 of the fiber connector 1 has a first cylindrical portion 34 with a smaller diameter, which absorbs the aforementioned jacket modes 33. Furthermore, the Ferrulenaufnahme 28 has a second cylindrical portion 35 with a larger diameter, which rests against the fiber connector socket 4 and the heat 38 of the absorbed radiation in the

Fiber socket 4 initiates. In this case, the fiber connector 4 can be provided with a suitable cooling. Furthermore, from Fig. 8 schematically a clamping claw 36 can be seen, which presses the second cylindrical portion 35 of the Ferrulenaufnahme 28 against the fiber connector socket 4 and thereby the exact

Guaranteed positioning of the ferrule 3 in the axial direction. The pressing is with reference to Figs. 9 to 11 in

Explained in detail below.

Fig. 9 shows schematically a device for the connection

Fiber socket 4 with a fiber connector. In Fig. 9 to Fig. 11 are both the fiber connector socket 4, as well as with a

Fiber optic 2 connected fiber connector 1 with ferrule 3 only

shown schematically. In particular, the illustrated components are rotationally symmetrical components.

In addition to a clamping sleeve 5, which can ensure a high lateral and directional positional accuracy, an exact insertion depth be respected. For this purpose, both the fiber connector socket 4, and the fiber connector 1 each have a stop 37, 38, which are pressed against each other.

The juxtaposition of the stops 37, 38 takes place by

Clamping devices. As a clamping means is used in the embodiment of FIG. 10 is a schematically illustrated clamping claw 36. In this case, the clamping claw 36 a plurality of distributed over its circumference

Grub screws 39, can be screwed onto the counterparts, not shown, such as nuts. As clamping means is used in the embodiment of FIG. 11, a clamping ring 40. In this case, the clamping ring 40 can be screwed into a fixedly connected to the fiber connector socket 4 sleeve 41.

Through both embodiments of the clamping means is a

ensures rotationally symmetrical contact pressure on the stop surfaces, so that the precise lateral clamping is not

being affected.

Claims

claims:

1. Device for the connection of two at least partially

telescoping, optical components with each other, wherein the first component has a cylindrical portion,

characterized in that the device comprises clamping means which in the radial direction a force on the

cylindrical portion of the first of the two components can exercise.

2. Device according to claim 1, characterized in that the clamping means comprise a clamping sleeve (5) into which the cylindrical portion of the first component is at least partially inserted.

3. A device according to claim 2, characterized in that the clamping sleeve (5) at least two, at least partially extending in the circumferential direction, in the radial direction by a gap (13, 18, 19, 20, 21) from each other

spaced portions (14, 15, 22, 23, 24, 25, 26, 27).

4. Apparatus according to claim 3, characterized in that at least one of the sections (14, 15, 22, 23, 24, 25, 26, 27) is a radially inner portion (14, 22, 23).

5. The device according to claim 4, characterized in that the at least one radially inner portion (14, 22, 23) acts as a spring element which encloses the cylindrical portion of the first component and laterally positioned.

6. Device according to one of claims 2 to 5, characterized in that the clamping sleeve (5) has an inner

Cross-section which deviates from a circular shape.

7. Apparatus according to claim 6, characterized in that the inner cross section of the clamping sleeve (5) by at least two sections (14, 15, 22, 23, 24, 25, 26, 27) with

circular inner cross section is formed.

8. The device according to claim 7, characterized in that the centers of the circular inner cross sections of the at least two sections (14, 15, 22, 23, 24, 25, 26, 27) are displaced in the transverse direction against each other.

9. Device according to one of claims 7 or 8, characterized

characterized in that the radii of the circular

Inner cross sections of the at least two sections (14, 15, 22, 23, 24, 25, 26, 27) differ from each other.

10. Device according to one of claims 2 to 9, characterized

characterized in that the clamping sleeve (5) made of metal, for example made of brass, or metal, such as brass, comprises.

11. Device according to one of claims 1 to 10, characterized

characterized in that the second of the components a

Fiber connector socket (4) of an optical beam source or a fiber connector socket (4) comprises an optical beam source.

12. Device according to one of claims 1 to 11, characterized

in that the first component is a sliding sleeve, a ferrule (3) or a rod or another axially symmetrical Component is or that the first component comprises a sliding sleeve, a ferrule (3) or a rod or other axially symmetric component.

13. Device according to one of claims 1 to 12, characterized

characterized in that the device comprises at least one stop (37, 38) and clamping means, the one

Section of at least one of the components against the at least one stop (37, 38) can press.

14. The apparatus according to claim 13, characterized in that the clamping means as a clamping claw (36) or clamping ring (40) are formed or a clamping claw (36) or a

Clamping ring (40) include.