DE202018101581U1 - Fiber optic cable with plugs - Google Patents

Abstract

A multilayer optical waveguide comprising a first optical material as a core and at least one further optical material as a cladding of the core, and further comprising at least one connector for connection to at least one further optical element at both ends of the optical waveguide, the volume of the cladding of the core having micro-modifications, to uncouple jacket light laterally.

Description

FIELD OF THE INVENTION

The invention relates to a light guide cable with an at least two-layer optical waveguide with at least one plug.

BACKGROUND OF THE INVENTION

Optical fibers or optical fibers serve to transmit light. Optical waveguides may have a multilayer construction wherein a first optical material is used to form a central, light-bearing portion of the optical waveguide, also referred to as a core, and at least a second optical material surrounding the core. This second part is also referred to as cladding or cladding. Light can be held in the nucleus by total internal reflection at the interface between the core and the cladding.

A method known from the prior art for removing so-called cladding light (also cladding light) is a technique which is referred to as "high index polymer coating". This technique consists of coating the cladding surface with a polymer of high refractive index. The high refractive index polymer coating violates TIR (Total Internal Reflection) at the boundary of the cladding and polymer layer, thus coupling out the unwanted cladding light. The remaining light will be as desired only the transmitted core light.

Another technique for decoupling the cladding light is to etch the cladding surface by applying an etchant in different amounts (with different effects) along the cladding surface. The rough surface resulting from this treatment removes the cladding light uniformly over the length of the multilayer optical fiber.

An additional method has a plurality of transverse notches or depressions in the cladding surface of an exposed optical fiber. These microstructures are preferably fabricated with a laser ablation system and can penetrate into the core of the fiber and thereby inhibit total internal reflection at the cladding-air junction or core-cladding transition, so that the light at the interface is scattered and decoupled.

These methods can also be used in combination. Both etched fibers and laser-textured cladding surface may additionally be coated / coated with a high refractive index polymer. As a result, the numerical aperture of the cladding light and the refractive index distribution are reorganized so as to ensure an increase in the power loss with a uniform scattered light distribution.

The publication of the US application US 2006/0147170 A1 relates to a method for microstructuring an optical waveguide having a first cross-sectional area with a first refractive index, a second cross-sectional area with a second refractive index, and a boundary region in the transition from the first to the second cross-sectional area, wherein the optical waveguide with laser radiation in the form of at least one ultrashort single pulse or a pulse train is irradiated with a defined energy input, wherein the irradiation takes place in such a way that at least one defined portion of the boundary region, a modification of at least one optical property of the optical waveguide occurs. This patent application accordingly relates to an optical fiber having a two-part optical structure of sheath and core, wherein the structuring is provided on the surface of the core.

The DE 10 2015 119 875 A1 relates to an optical waveguide comprising a core guiding light waves, a region of the optical waveguide, micro-modifications being arranged in the region of the optical waveguide, the arrangement of micro-modifications being arranged, and a method for producing an optical waveguide according to the invention.

This application also relates to the structuring of the core of a multilayer optical waveguide.

Jacket light may cause a higher beam parameter product of the transmitted laser light. Furthermore, a thermal deterioration of the fiber properties can be caused by the cladding light.

A particular problem in the coupling out of cladding light arises in the range of connectors of an optical waveguide for connection to other optical elements, since in this mostly short range of the plug thermal stresses by cladding light can have a particularly adverse effect on the efficiency of the optical waveguide.

The object of the present invention is to provide a multilayer optical fiber with reduced cladding light connector for improving the efficiency in the transmission of laser light.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a multilayer optical waveguide comprising a first optical material as a core and at least one further optical material as a cladding of the core, and further at both ends of the optical waveguide at least one connector for connection to at least one further optical element, wherein the volume of Sheath of the core has micromodifications to decouple cladding light laterally.

In the optical waveguide according to the invention, an embodiment is provided in which the micro-modifications were induced by means of lasers, for example ultrashort-pulse lasers.

Furthermore, the micro-modifications may be introduced in a random pattern in the volume of the sheath.

Alternatively, embodiments are provided in which the micro-modifications can be introduced symmetrically, radially symmetrically or in a pattern in the volume of the sheath.

It is also envisaged that the micromodifications of an optical waveguide can be introduced in the entire volume of the cladding such that cladding light is coupled out radially symmetrically.

In a further embodiment of the invention, the volume of the sheathing of the optical waveguide has micro-modifications only in the region of the at least one plug.

Another object of the present invention comprises the sheath of a core of an optical waveguide whose volume has micro-modifications induced by ultrashort-pulse laser.

In one embodiment of the cladding of the optical waveguide, it is provided that the micro-modifications of the volume of the cladding are present only in the region of the at least one plug of the optical waveguide for connection to a further optical element.

list of figures

• 1 Lichtwellenleiter mit Steckern
• 2 Perspektivischen Querschnitt durch einen Stecker
• 3 Ergebnisse von Vergleichsversuchen

The invention is illustrated in more detail below with reference to figures. It is obvious to the person skilled in the art that these are only possible embodiments, without the invention being restricted to the embodiments shown. It shows:

• 1 Fiber optic cable with plugs
• 2 Perspective cross section through a plug
• 3 Results of comparative experiments

DETAILED DESCRIPTION OF THE INVENTION

As an optical element in the context of the present invention, elements are to be understood which are suitable for the transmission of light or laser radiation. These may be optical fibers, fibers, lenses or lens groups. Elements for coupling in light are also covered by this term.

The terms cladding light and cladding light are to be understood in the description of the present invention synonymous.

The present invention provides an at least two-layer structured optical waveguide which has a plug for connection to a further optical element at least at one end.

The present invention has the advantage that no hazardous chemicals are used in the manufacture of optical waveguides with microstructured claddings of a core. The two-layer construction comprises a core and a jacket. In the present invention, the patterning of the optical waveguide is limited to the volume of the cladding.

To avoid thermal effects by jacket light in the short portion of the sheath in a plug, it is provided according to the invention to provide the sheath only in the area within the plug with a microstructure.

The microstructuring according to the present invention is achieved by irradiation of the cladding with a laser, such as an ultrashort pulse laser, whereby scattering centers are inserted into the volume of the cladding. These micro-modifications prevent the total reflection of the jacket light and this is decoupled laterally.

According to the invention, the sheath is provided with micro-modifications which bring about a radially symmetrical decoupling of the sheath light. In the entire cladding volume can be arranged specifically micro-modifications.

In addition, the optical waveguides or the cladding of the core of an optical waveguide can be produced automatically, which is the Speed and also costs of production lowers. The areas of the desired microstructuring can also be very selectively limited, z. B. only on the range of connectors for connection to other optical elements.

1 shows an optical fiber 1 with plugs 5 and protective hose 25 at its ends for connection to further optical waveguides (not shown).

2 shows a perspective cross section through a plug of an optical waveguide according to the invention 1 , It's core 10 and sheath 15 of the optical fiber 1 to see. The volume of the casing 15 has microstructures 20 for decoupling the cladding light.

From the in 3 It can be seen that the microstructuring of the cladding volume in the region of the plug leads to an unpredictable increase in the efficiency of the optical waveguide by up to 20% and to a good reproducibility of the mode stripper produced by the method of the invention. Thus, the invention provides an advantageous alternative to the known from the prior art optical waveguides, since not as in the prior art, the core is provided with microstructures, but the volume of the sheath in the region of the plug.

LIST OF REFERENCE NUMBERS

1

optical fiber

5

plug

10

core

15

jacket

20

microstructuring

25

Conduit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2006/0147170 A1 [0007]
• DE 102015119875 A1 [0008]

Claims (8)

A multilayer optical waveguide comprising a first optical material as a core and at least one further optical material as a cladding of the core, and further comprising at least one connector for connection to at least one further optical element at both ends of the optical waveguide, the volume of the cladding of the core having micro-modifications, to uncouple jacket light laterally. The multilayer optical waveguide after Claim 1 , where the micro-modifications were induced by laser. The multilayer optical waveguide according to one of Claims 1 or 2 , wherein the micro-modifications are introduced in a random pattern in the volume of the sheath. The multilayer optical waveguide according to one of Claims 1 or 2 , wherein the micro-modifications are introduced symmetrically, radially symmetrically or in a pattern in the volume of the sheath. The multilayer optical waveguide according to one of Claims 1 to 4 , wherein the micro-modifications are introduced in such a way in the entire volume of the sheath that jacket light is coupled out radially symmetrically. The multilayer optical waveguide according to one of Claims 1 to 5 , wherein the volume of the casing has micro-modifications only in the region of the at least one plug. The cladding of a core of a multilayer optical waveguide whose volume has micromodifications induced by ultrashortpulse lasers. The sheath after Claim 7 wherein the volume of the sheath comprises micromodifications only in the region of the at least one plug of the optical waveguide, for connection to a further optical element.

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