EP3322934A1

EP3322934A1 - Laterally emitting optical waveguide and method for introducing micromodifications into an optical waveguide

Info

Publication number: EP3322934A1
Application number: EP16738059.1A
Authority: EP
Inventors: Manuela SCHWAGMEIER; Verena Knappe; David Ashkenasi; Hans-Joachim Cappius
Original assignee: Clinical Laserthermia Systems GmbH
Current assignee: Clinical Laserthermia Systems GmbH
Priority date: 2015-06-19
Filing date: 2016-06-15
Publication date: 2018-05-23
Also published as: US20200225405A1; BR112017027416B1; US20180299614A1; JP7173547B2; US20240012196A1; JP2018525683A; DE102015119875A1; AU2016278511A1; KR20230113403A; AU2016278511B2; US20200225406A1; KR102555863B1; HK1248824A1; WO2016202328A1; KR102674240B1; CA2989675A1; CN107873087A; US11215750B2; KR20180019170A; CN115857084A

Abstract

The present invention relates to an optical waveguide comprising a light wave-guiding core, a region of the optical waveguide, wherein micromodifications are provided in the region of the optical waveguide, wherein the micromodifications are arranged in an ordered manner; and a method for producing an optical waveguide according to the invention.

Description

Lateral-emitting optical fibers and method for introducing micro-modifications into an optical waveguide

The invention relates to an optical waveguide, and a method for introducing micro-modifications in an optical waveguide.

In the prior art known optical waveguides are usually made of an optical waveguide core (hereinafter referred to as the core) and an optical waveguide jacket (hereinafter referred to as coat). Here, quartz glass is a commonly used manufacturing material, but is not limited thereto. In order to ensure lossless light guidance within the core, the refractive index of the cladding is less than the refractive index of the core. As a result, the total reflection can be utilized at the transition between the core and the cladding, so that guidance of the light in the core of the optical waveguide occurs. Sometimes the coat is covered with another cladding. Often, conventional optical waveguides additionally have a so-called coating and / or a buffer which can surround the cladding. These additional layers are usually designed so that they serve the mechanical stability of the optical waveguide in general and in particular ensure the non-destructive flexibility of the optical waveguide and the mechanical protection of the optical waveguide from external influences.

Usually, the light injected into the core on one side into the core is coupled out of the optical waveguide within the core almost losslessly at the other end of the optical waveguide. In order to change the light path of the light within the core, it is known to introduce modifications in the material of the core or in the edge region between core and cladding. By diffraction and / or scattering and / or refraction of the light on these described as disturbances modifications of the light path can be changed so that thereby a targeted lateral extraction of at least portions of the guided in the core of the optical waveguide light can be achieved. Are the set modifications over a defined distance along the core and / or the border area between core and Mantle has been introduced, so the lateral coupling can also be done over this defined route.

These so-processed areas can serve as so-called fiber applicators, which are usually carried out at one end of the optical waveguide or in between. It is also known to realize these so-called fiber applicators essentially by externally attached attachments. Thus, e.g. waterproof finished lugs known which are placed at one end of the optical waveguide on the optical waveguide. It serves to change the light path for the lateral coupling of the light either the mechanically and / or chemically roughened end of the optical waveguide, or a scattered with particles scattered liquid which circulates in the liquid-tight executed essays. Such applicators are e.g. from DE 41 37 983 C2, DE 42 1 1 526 A1 or DE 43 16 176 A1.

Another design of such a patch applicator, as e.g. DE 101 29 029 A1, US Pat. No. 4,660,925 or US Pat. No. 5,196,005 discloses a cap designed as a hollow body which is fastened to one end of the optical waveguide. The hollow body is provided with a carrier matrix, e.g. filled with a silicone gel into which are introduced the particles serving as scattering centers. The concentration of the scattering particles can be homogeneously distributed or increased sequentially towards the end.

Such patch fiber applicators are usually made of polymer materials and therefore very elastic and mechanically strong, but also have significant disadvantages, which are based essentially on the two-part design of optical fiber and attached applicator. For example, the thermal capacity of patch applicators is usually much lower than that of the optical fibers. Likewise, in such applicators the Danger of detachment from the optical fiber. Typically, the various manufacturers of such patch applicators use different materials, resulting in correspondingly different thermal and mechanical properties of the applicators and these are only suitable for certain wavelengths and powers. As a result, a change between different applicators is much more difficult, especially since these fiber applicators are optimized for specific applications. Another major disadvantage of attached applicators lies in the manufacturing process. The assembly is usually done by hand and is not automated due to the complexity. In addition, blistering or foreign body entrapment may occur during manufacture, whereupon the light breaks disproportionately and leads to so-called undesired hotspots, resulting in a relatively high rejection rate.

In DE 44 07 547 AI a method for introducing modifications in the interior of transparent materials, using focused laser radiation is described. In the process, microcracks are generated with the help of laser pulses in the nanosecond range within the transparent material, which can serve as light scattering centers. It is precisely these microcracks produced in this way that represent a problem in the transmission of this method to the application in the case of optical waveguides. For these cracks would lead to such a material weakening within an optical waveguide that occurs during thermal or mechanical loading, e.g. Bending of the optical fiber, which may result in damage or even breakage of the optical fiber. In addition, these microcracks are not controllable in size and orientation to the optical waveguide axis.

From DE 197 39 456A1 a method for introducing, as scattering centers serving, micro-modifications in an optical waveguide is known. Here, the processing parameters, such as the pulse duration of the laser radiation used, are not described in detail, so that the exact expression of the resulting micro-modifications is indefinite. The exact form, however, affects crucial to the radiation and mechanical stability of the optical fiber.

Likewise known from EP1342487 B1 is a laser applicator which comprises an optical waveguide which has scattering means which are suitable for scattering the light guided in the interior at least in part out of the core of the optical waveguide, at least part of the scattering centers forming a diffraction grating. Although methods are described which are suitable to introduce the scattering centers in the interior of the optical waveguide, the exact adjustment of the parameters, which is necessary to control the expression of the scattering centers is not described.

WO 2004/005982 A2 describes a method for the microstructuring of optical waveguides, in which ultrashort laser pulses are used. This and the other methods mentioned above are generally formulated and contain information on the shape, size and distribution / arrangement of the microstructures produced without going into any special design with regard to the thermal and mechanical stability, both with regard to the microstructures and the processed optical waveguides.

It is known that bending or other loading (eg mechanical and / or thermal) of the optical waveguide can lead to mechanical failure (breakage of the optical waveguide) if the stresses occurring in the interior of the optical waveguide influence the mechanical stability too much. Already during the manufacturing process, in particular during the drawing process, microcracks may occur in the outer region of the optical waveguide jacket. By means of the mechanical connection between the coating (and / or the buffer) and the jacket surface of the jacket, the resulting stresses can be dissipated so that there is no reinforcement (so-called crack propagation) and therefore not too an impairment of the mechanical stability of the optical waveguide comes. It is also a known problem that any further processing of the interior of the optical waveguide, such as the core or the jacket, affects the mechanical stability of the optical waveguide. As a result, voltages which can still tolerate an unprocessed optical waveguide lead to a crack propagation in a processed optical waveguide, which can lead to breakage of the optical waveguide.

It is an object of the invention to avoid or reduce one or more disadvantages in the prior art. It is a particular object of the invention to provide an optical waveguide which is suitable for laterally emitting at least parts of the light guided in the interior and at the same time has the highest possible mechanical stability. It is a further object of the invention to provide a method for introducing micromodifications into an optical waveguide, which are suitable for laterally emitting at least parts of the light guided in the interior of the optical waveguide.

The object is achieved on the basis of an optical waveguide according to the preamble of claim 1 by the features stated in the characterizing part of claim 1, as well as by the features of the method mentioned in claim 11 for the introduction of micro-modifications.

The optical waveguide according to the invention comprises a core guiding the light wave, a region at the distal end of the optical waveguide, micro-modifications being arranged in the region in the distal end of the optical waveguide, the arrangement of the micro-modifications being ordered. Compared to a disordered or chaotic distribution, it is possible by an ordered distribution of micro-modifications to control the voltage distribution and the radiation geometry in the optical waveguide. In a disorderly distribution, it could happen that in the Range of voltage spikes further micro-modifications are placed, which further increase the voltage. This inevitably leads to a further mechanical weakening in this area, which can lead to damage of the optical waveguide. If the micro-modifications are introduced in an orderly manner, the stress distribution can be actively controlled. This makes it possible that the mechanical load is distributed by the micro-modifications so that in comparison to optical waveguides with a chaotic distribution of micro-modifications higher mechanical loads can be introduced before the optical fiber fails. Furthermore, by a targeted arrangement of the micro-modifications, the processing time can be reduced, since only there micro-modifications are introduced, where they also contribute meaningfully to the lateral radiation of the light guided in the optical waveguide. In a disordered distribution of micro-modifications, this is not guaranteed. Therefore, with a disordered distribution of micromodifications, more micromodifications must be introduced to achieve the same laterally radiated intensity than with an ordered array of micromodifications.

In a preferred embodiment of the optical waveguide, the micro-modifications are arranged on one or more parallel slices, the first slicing plane being perpendicular to the optical waveguide axis, and the micro-modifications on the first slicing plane arranged by one or more parameters from a group of parameters including the symmetrical arrangement the micro-modifications, the density of micro-modifications on the first cutting plane, the density of the micro-modifications, the size of the micro-modifications, the distance of the micro-modifications to the optical fiber axis, the distance of the micro-modifications to each other, the alignment of the micro-modifications or other parameters, with the help of the position and distribution the micro-modifications or their size or external shape is described. In a further preferred embodiment of the optical waveguide, the arrangement of the micro-modifications is repeated on a first cutting plane on at least one other cutting plane. This has the advantage that processing routines can be repeated and also a stress distribution produced by a certain arrangement of micro-modifications can be continued over a relatively long range.

In a further particularly preferred embodiment of the optical waveguide, the at least one other cutting plane on which the arrangement of the micro-modifications is repeated on the first cutting plane is rotated relative to the first cutting plane by an angle.

In a further particularly preferred embodiment of the optical waveguide, the distance between the first cutting plane and the at least one other cutting plane on which the arrangement of the micro-modifications is repeated is greater than the extent of a single micro-modification.

In a further embodiment of the invention, the distance between the first cutting plane and the at least one other cutting plane on which the arrangement of the micro-modifications is repeated, less than the extension of a micro-modification in the axial direction of the optical waveguide, as long as the micro-modifications do not overlap or the beam passage hinder.

In a further particularly preferred embodiment of the optical waveguide, between the first cutting plane and the at least one other cutting plane on which the arrangement of the micro-modifications of the first cutting plane is repeated, at least one further cutting plane with micro-modifications having a different arrangement than the first cutting plane. In a further particularly preferred embodiment of the optical waveguide, the micro-modifications on the first sectional plane are rotationally symmetrical about the optical waveguide axis.

In a further particularly preferred embodiment of the optical waveguide, the micro-modifications are arranged on a hollow cone, wherein the longitudinal axis of the hollow cone lies on the optical waveguide axis.

In a further particularly preferred embodiment of the optical waveguide, the micro-modifications are arranged on a plurality of hollow cones, wherein the hollow cones have different diameters and, wherein the longitudinal axes of the hollow cones lie on the optical waveguide axis. The micro-modifications do not have to fill the entire area of the cone to the tip, which u.a. truncated cones or spirals are trapped on a cone.

In a further particularly preferred embodiment of the optical waveguide, the region at the distal end of the optical waveguide in the direction of the optical waveguide axis is subdivided into two sections, of which a first section faces the distal end of the optical waveguide and the second section faces away from the distal end of the optical waveguide.

Another particularly preferred embodiment is to subdivide the machined region of the optical waveguide into at least two sections in which different ordered micro-modifications are respectively introduced in different orientations and embodiments. The method according to the invention for introducing micromodifications into optical waveguides comprises fixing an optical waveguide in one or more mountings, the optical waveguide and / or the mount being movably mounted, focusing high-energy laser radiation with a focusing device into a focus position, the focal position in the interior of the optical waveguide can be positioned, wherein the radiation is generated by a radiation source in the pulse mode, wherein the focusing device for focusing the high-energy radiation is movably mounted, moving the focus position through the optical waveguide, wherein the movement of the focus position inside the optical waveguide is selected selectively in dependence on the repetition rate to produce a predetermined array of micro-modifications.

The method for introducing micromodifications into optical waveguides preferably comprises the movement of the optical waveguide in a rotational movement.

In a preferred embodiment of the method for introducing micromodifications into optical waveguides, the focal position is continuously moved through the optical waveguide.

In a further preferred embodiment of the method for introducing micromodifications into optical waveguides, the movement of the focal position through the optical waveguide comprises a combination of rotational and one or more translatory movements.

In a further preferred embodiment of the method for introducing micromodifications into optical waveguides, the movement of the focus position is correlated with the repetition rate in such a way that an ordered uniform or systematically changing arrangement of micromodifications arises in the optical waveguide. In a further particularly preferred embodiment of the method for introducing micromodifications into optical fibers, the arrangement of the micro-modifications is characterized by one or more parameters from a group of parameters comprising the symmetrical arrangement of the micro-modifications, the density of the micromodifications on the section plane, the size of the micro-modifications, the distance of the micro-modifications to the optical fiber axis, the distance of the micro-modifications to each other, the alignment of the micro-modifications or other parameters, with the help of the location and distribution of micro-modifications or their size or external shape, described.

In a further particularly preferred embodiment of the method for introducing micromodifications into optical waveguides, the irradiation direction of the radiation onto the optical waveguide takes place at an angle between the optical waveguide axis and the direction of irradiation not equal to 90 °, in a preferred range at an angle of not equal to 90 ° +/- 5 ° , in a particularly preferred range under a degree of unequal 90 ° +/- 10 °.

In a further particularly preferred embodiment of the method for introducing micromodifications into optical waveguides, the focusing device is additionally set into oscillation in lateral and transversal directions.

Preferably, in the method for introducing micro-modifications, a laser system is used which is capable of generating ultrashort laser pulses. The pulse length is preferably in the range between 0.01 and 1000 ps, more preferably in the range between 0.05 and 10 ps, very particularly preferably between 50 and 500 fs. The wavelengths used range from the visual to the near infrared range and are, preferably between 300 and 1500 nm, more preferably between 500-532 nm or 1000-1064 nm. The range of used Single pulse energies is preferably between 1 and 100 μ, more preferably 1 to 50 μ. This results in the focus range power densities between 10 ¹² and 10 ¹⁵ W / cm ² .

The used or achievable repetition rate of the laser system decisively determines the processing speed when introducing micro-modifications into an optical waveguide. The higher the repetition rate, the faster the focusing device can be moved with a constant distance of the micro-modifications. A high repetition rate is therefore to be preferred. However, it should be noted that the machining axes must be able to be moved correspondingly quickly and precisely. Furthermore, at very high repetition rates greater than or equal to 1 MHz, heat accumulation within the optical waveguide may occur, since the energy introduced into the irradiated volume of the optical waveguide can no longer be dissipated quickly enough. This heat accumulation can lead to stress cracks and thus to a mechanical instability or even to the destruction of the optical waveguide. Preferably, therefore, a repetition rate in the range of 1 kHz to 1 MHz, more preferably 1 and 100 kHz is selected.

The use of ultrashort light pulses (pulse duration <10 ps) has the advantage that the influence of the registered heat energy remains very low, which allows the introduction of spatially limited micro-modifications without damaging the surrounding material. When laser pulses in the nanosecond range are used, the energy is delivered to the ionic lattice of the irradiated material during a single pulse. This leads then, just as in the case of an excessive repetition rate, to a heat accumulation in the irradiated material volume and to the formation of microscopic stress cracks, the extent of which may well be in the millimeter range. These damage to the material of the optical waveguide can lead to a limitation of the mechanical stability, up to the possible breakage of the optical waveguide under mechanical and / or thermal stress. The use of ultrashort laser pulses allows a targeted change in the material properties only in the irradiated area of a few micrometers, without damaging surrounding areas unintentionally. The pulse duration is insufficient in this case to deliver the energy to the ion lattice of the surrounding material, so that there is no or a greatly reduced heat accumulation. This allows very small structures to be generated at very low stresses in the surrounding material. Both the smallest possible structures and the lowest possible voltages are necessary conditions for the targeted introduction of micro-modifications in optical waveguides. Only in this way is the targeted structuring of the optical waveguide material possible without ensuring the mechanical stability of the optical waveguide.

For the method of introducing micromodifications into optical fibers, a device is provided which comprises an axis and motor system. On the one hand, this device serves to hold the optical waveguide and, on the other hand, the device allows the optical waveguide to be selectively moved, rotated and allows any desired positioning of the focus of the laser system within the optical waveguide. The method according to the invention and the associated device according to the invention allow the shape, the distribution and the position of the micro-modifications within the optical waveguide to be varied as desired. For example, the position or the form of the micro-modifications can be influenced in a targeted manner by the travel speed of the linear and rotational axes or by varying the repetition rate. The distribution of the micro-modifications can also be controlled in a targeted manner, for example by so-called laser-internal "pulse picking" or a programmable shutter The depth of the micro-modifications relative to the surface of the optical waveguide jacket can be influenced by targeted movement of the focus, by selective adjustment of the focusing device is also the depth extent of the individual micro-modifications, by an appropriate choice of single pulse energy, pulse duration, pulse rate (single, double, multiple pulse), spatial It is also possible to introduce micromodifications on the side facing away from the laser system into the optical waveguide by focusing through the center of the optical waveguide The focus position or positioning of the focusing device relative to the optical waveguide axis influences the arrangement of the micro-modifications, so that the position of the micro-modifications can be modified by shifting the irradiation position out of the optical waveguide Lot to the fiber optic axis to control the alignment of the micro-modifications.

Any parameters by which the micro-modifications can be described, e.g. the depth position, the spatial extent, the distribution, the distance from one another, the position, the orientation or even the shape of the micro-modifications can have an influence on the mechanical stability of the optical waveguide. The smaller the spatial extent of the micro-modifications and the greater the distance of the micro-modifications to one another, the lower the influence on the mechanical stability of the optical waveguides. On the other hand, it is also the case that the strength of the light extraction, which is caused by the micro-modifications, is essentially opposite to the effects on the mechanical stability. Thus, it is essential to find a compromise between the decoupled light intensity and the mechanical or thermal stability of the optical waveguide.

With regard to the distribution of the micro-modifications, various designs are conceivable. It is thus possible, for example, to produce a deliberately irregular distribution of the micro-modifications in order to avoid lattice effects, such as interferences, and at the same time to ensure a uniform distribution of the coupled-out light. On the other hand, a targeted regular or periodic distribution of micro-modifications, such as Bragg gratings or multi-dimensional photonic structures, conceivable. Furthermore, it is possible to close the micro-modifications inside the optical waveguide so that these modifications form a line which itself has waveguide properties. This line structure can be made arbitrarily long and their course relative to the optical waveguide can also be carried out arbitrarily, so, for example, a straight-line or spiral or a helical design is conceivable.

The processing options described are not limited to a specific type of optical waveguide. By suitably adjusting the machining parameters, it is possible to use any type of optical fiber, e.g. Hollow fibers, gradient index fibers, novel high-tech glass fibers without lead, photonic crystals, or photonic crystal fibers to edit.

The invention will be explained in more detail with reference to several embodiments. Show it:

FIG. 1 Schematic structure of an optical waveguide with micro-modifications induced by laser radiation. FIG. 2 Schematic representation of an optical waveguide and the coupling of focused laser light and the possibilities of the invention

Relative movement between focused laser light and optical fiber

Figure 3 Schematic structure of the processing device for processing

Optical fibers

a) front view

b) side view

FIG. 4 Method for processing optical waveguides with laser radiation Schematic structure of an optical waveguide with laser radiation induced micro-modifications

a) optical fiber

b) Cross sections along the section lines A-A, B-B, C-C, D-D and E-E

Schematic structure of an optical waveguide with laser radiation induced micro-modifications

a) optical fiber

b) Cross sections along the section lines A-A, B-B, C-C, D-D and E-E

a) optical fiber

b) Cross sections along the section lines A-A, B-B, C-C, D-D and E-E

a) - e) Cross sections along the sections A - A, B - B, C - C, D

- D and E - E

f) Cross section along the optical waveguide axis

FIG. 9 Schematic structure of an optical waveguide with micro-modifications induced by laser radiation

a) - c) different periodic sequences FIG. 10 Schematic structure of an optical waveguide with micro-modifications induced by laser radiation

a) Sequence of cross-sections with different distribution and / or arrangement of micro-modifications

b) Periodic sequence of regions with the same sequence of cross-sections with different distribution and / or arrangement of micro-modifications

FIG. 1 shows a schematic representation of the optical waveguides (1) to be processed. The optical waveguide comprises a first region (15), which is largely free of micro-modifications (5), and a second region (16) of the optical waveguide (1), in which micro-modifications (5) are introduced. This region (16) is usually arranged at the distal end of the optical waveguide (1). Optionally, the optical waveguide may be provided with an end cap (14) which prevents light from exiting the end region of the optical waveguide (1). This end cap (14), by mirroring the light waves, can re-apply them to lateral outcoupling by micro-modifications. The end cap (14) can be replaced by a suitable, direct mirroring of the fiber end face, which is also according to the invention. The core (1 1) is surrounded by the jacket (12), followed by the coating and / or buffer (13). Core (11) and cladding (12) are usually made of quartz and are doped differently. The refractive index of the cladding material is less than that of the core material, in this way the light can be transported by total reflection at the core-cladding junction in the optical waveguide (1). The sheath (12) is surrounded by a so-called coating and / or buffer (13), which absorbs the stresses during bending of the optical waveguide (1), thus ensuring the non-destructive flexibility and also serves to protect against mechanical effects on the underlying layers. For the processing of the optical waveguide (1), the non-transparent for the selected laser wavelength buffer (13) are removed, so that the laser light must be focused only through the jacket (12). At for the selected laser wavelength transparent buffer material, such as nylon or PTFE, the optical waveguide (1) can also be processed through the buffer (13). This has the advantage that the machined region of the optical waveguide (1) has essentially the same increased flexural strength as the rest of the optical waveguide (1).

In Figure 2, the principle of the coupling of the focused laser light (2) in the optical waveguide (1) for introducing the micro-modifications (5) is equally shown. FIG. 2 shows the focusing optics (21) required for focusing the laser pulses in the core region of the optical waveguide (1) and the micro-modifications (5) produced. Important lens parameters for introducing the micro-modifications (5) into the optical waveguides (1) are the focal length and the numerical aperture (NA) of the focusing optics (21) shown symbolically. The focal length is chosen as short as possible, as this will minimize the size of the focus point. However, the focal length must be long enough to be able to focus through the optical waveguide jacket into the core (11). In a preferred variant, the focal length of the focusing optics (21) is between 1 and 5 mm. However, the use of "long-distance" microscope objectives with a working distance of more than 5 mm is also a preferred implementation option, and the greatest possible NA of the focusing optics (21) is advantageous since this determines the aperture angle of the focusing optics (21) The larger the opening angle, the shorter the focus area, which is of great importance since it minimizes the depth extent of the introduced modifications 5. The larger opening angle leads to a higher beam divergence and thus to a rapidly increasing beam diameter in front of and behind the focal point This reduces the energy density in the areas in front of and behind the focus and thus also the absorption and the danger of damage outside the focus area.

In a particularly preferred variant, a short focal length (f <3, 1 mm) aspherical lens with a numerical aperture of NA> 0.68 is used as the focusing optics (21). In a further embodiment, there is a special one Lens (lens system) with a high NA is used. This is designed so that the wavefronts of the focused laser radiation (22) have the same radius of curvature as the surface of the material to which they strike. This has the advantage that when passing through the optical waveguide surface, the wavefronts are not distorted (wave front distortion), which in turn leads to a significantly better focusability in the material of the optical waveguide (1).

FIG. 3 shows a schematic diagram of the device according to the invention for introducing micromodifications into optical waveguides (20). The device (20) comprises various motorized adjusting devices (33, 34) for performing a linear movement between optical waveguide (1) and focus of the focused laser beam (22). The movement preferably takes place via linear motors (33, 34) in the spatial directions (X, Y, Z). Furthermore, the device (20) comprises the structure for coupling (23) of the laser light (2) in the focusing optics (24). Furthermore, the device (20) comprises the holder (32) for the optical waveguide (1) and the axes of rotation (α, ßi, ß ₂ , ß ₃ ) for rotation thereof. In contrast to the previously known solutions, the focusing lens is not moved, but only the optical waveguide (1). This has the advantage that no deflection mirror must be moved or moved in the beam path during processing. As a result, the Einrichtungsbzw. Justageaufwand for the device significantly lower and at the same time results in a better long-term stability of the structure, since all optical elements in the beam path can be permanently installed. Even slight inaccuracies or deviations in the beam path would lead to a migration of the laser beam (2) on the focusing optics (24) in the case of translationally moving deflection mirrors, for example. As a result, the focal point in the XY plane as well as due to the (non-perpendicular) beam passage inclined relative to the optical waveguide (1) travels in the direction of the focusing optics (24). A long-term stable structure with reproducible processing results is very difficult or impossible to realize.

The Z-axis (34) carries the further processing structure consisting of X and Y axis (33), rotation device (31) and holder / guide (32) for the optical waveguide (1). It serves to move the optical waveguide (1) onto the Focusing optics (24) to or away from her. In this way, the distance of the focal point from the center of the optical waveguide (1), ie the depth position, can be varied. The X-axis (33) serves to move the optical waveguide or the holder / guide (32) along the optical waveguide path under the focusing optics (24). The maximum length of a modified area is thus determined only by the maximum travel of this axis. The Y-axis (33) moves the holder / guide (32) at right angles to the optical waveguide profile under the focusing optics (24). It serves to control the alignment of the micro-modifications (5), since with the Y-axis (33) the focusing optics (24) and the optical waveguide (1) can be aligned with each other so that the laser beam (2) meets as perpendicular to the optical waveguide surface , An oblique impact on the surface leads to an altered beam path with a distortion of the focus area and thus has an influence on the orientation and also influence on the shape and size of the introduced modifications. The laser beam (20) used is usually guided via a deflection mirror (23) in the focusing optics (24), but this is not mandatory. The optical waveguide (1) to be processed is held in a precise position in front of the focusing optics (24) by means of a holder and guide (32). This guide is recessed in the field of processing or transparent to the laser radiation used (2 or 22). The rotation device (31) serves to rotate the optical waveguide (1) about its longitudinal axis. For this purpose, the optical waveguide (1) is fastened with a tensioning device to the rotary device (31). In order to avoid an excessive torsional stress of the optical waveguide (1), this is always rotated stepwise by up to 360 degrees and then by up to 360 degrees in the opposite direction. This can be realized both for loose optical waveguide sections, eg prefabricated optical waveguides, and for roll-to-roll manufacturing processes in which the optical waveguides (1) can be of any desired length.

FIG. 4 shows in an embodiment of the invention a method for processing optical waveguides (1) with laser radiation (2). First, the Optical waveguide (1) by means of a holder / guide (32) fixed in position (41). The holder / guide (32) is designed so that the region of the optical waveguide (1) of the laser radiation (2) is accessible, in which the micro-modifications are to be generated. The optical waveguide is mounted so that it is movable in three spatial directions relative to the focal position. This can be achieved by a movable optical system (24) and rigid mounting of the optical waveguide (1), or by a rigid optical system (24) and a movably arranged optical waveguide (1). The movement possibilities include the three spatial directions X, Y, and Z and the rotation α about the longitudinal axis of the optical waveguide (1) and / or the rotation SSI, ß _2, sss about one or more axes. In a further method step (42), the laser beam (2) is focused. The focused laser beam (22) is positioned so that the position of the focus can be moved by means of the movement possibilities through the entire area in which micro-modifications are to be introduced. The focal position is moved by the optical waveguide according to a predetermined pattern (43). Preferably, a pulsed laser beam is used. By a continuous movement of the focal position through the optical waveguide (1) at a constant speed micro-modifications (5) with equidistant in the direction of movement distance. By moving the focus position through the optical waveguide (1) according to a predetermined pattern, 20 or more micro-modifications (5) are generated. In a preferred embodiment of the invention, more than 36 micro-modifications (5), more preferably more than 360 micro-modifications (5) are generated by the movement of the focus position through the optical waveguide (1) according to a predetermined pattern. In a further method step, the movement of the focus position through the optical waveguide (5) is repeated (44) according to a predetermined pattern.

In a further advantageous refinement, after completion of the micromodifications (5) introduced by the movement of the focal position through the optical waveguide (1) in accordance with a predetermined pattern, the focal position relative to the optical waveguide (1) is changed by a translatory and / or rotational movement. This serves to prevent the micro-modifications (5), which were introduced in the repetition step by the movement of the focus position through the optical waveguide (1) according to a predetermined pattern in the optical waveguide (1), in the direction of the optical waveguide axis (17) just behind the Micro modifications (5) lie, which were introduced in the first step by the movement of the focus position through the optical waveguide (1) according to a predetermined pattern in the optical waveguide (1).

In a further advantageous embodiment of the invention, the continuous movement of the focus position is performed by the optical waveguide (1) along the optical waveguide axis and so later gives one of the arrangements described in the sectional plane. Thus, the machining process is divided within several cutting planes so in the generation of individual points in each passage along the optical waveguide axis (17).

In a further advantageous embodiment of the invention, the continuous movement of the focus position is superimposed by the optical waveguide (1) according to a predetermined pattern by a further movement. This movement may, for example, be vibrations which serve to establish a certain lateral offset between the micro-modifications (5) introduced into the optical waveguide (1) in a repetitive step by the movement of the focus position through the optical waveguide (1) according to a predetermined pattern , and the micromodifications (5) introduced into the optical waveguide (1) in the first step by the movement of the focus position through the optical waveguide (1) according to a predetermined pattern. Preferably, the amplitude of the oscillation is at least half the distance of adjacent micro-modifications (5). This results in an ordered arrangement of micro-modifications in the sense of the present invention. The micro-modifications (5) are arranged in the optical waveguide (1) such that, when light is transmitted along the optical waveguide axis (17) through the optical waveguide, the micro-modifications are arranged such that the light is deflected to the side as completely as possible by the micro-modifications.

In a further advantageous embodiment of the invention, the micro-modifications (5) in the optical waveguide (1) introduced by the optical axis (25) of the laser beam (2) during the irradiation of the optical waveguide (1) the optical waveguide (1) away from the optical waveguide axis ( 17) is positioned. In the case of micro-modifications (5) whose shape deviates significantly from a round shape, that is to say have an elongated shape, a nearly closed surface or line of micro-modifications (5) can be achieved solely by a rotational movement.

In a further advantageous embodiment of the invention, the micro-modifications (5) in the optical waveguide (1) introduced by the optical axis (25) of the laser beam (2) during the irradiation of the optical waveguide (1) at an angle (ßi, ß ₂ , ßs) on the optical waveguide (1), which is not equal to 90 °. In micromodifications with an elongated shape, this results in an acute angle between the orientation of the micro-modification (5) and the optical waveguide axis (17). In a further embodiment of the invention, the angle (βi, β ₂ , βs) between the orientation of the micro-modification (5) and the optical waveguide axis (17) is in a range between 10 ° and 80 °, in a preferred embodiment in a range between 20 ° and 70 ° and in a particularly preferred embodiment between 30 ° and 60 °.

FIG. 5 shows the schematic structure of an optical waveguide with micro-modifications induced by laser radiation (partial image a) and sectional images along the sectional lines A-A, B-B, C-C, D-D and E-E (partial image b)). Of the Optical waveguide (1) is constructed by a core region (11) and a cladding region (12). By means of the irradiation according to the method (40) according to the invention, micro-modifications (5) were introduced into the core region (12) of the optical waveguide (1). The micromodifications (5) on the illustrated sectional planes (A - A, B - B, C - C, D - D and E - E) are rotationally symmetrical about the optical waveguide axis (17). The micro-modifications (5) have the same distance to the optical waveguide axis (17) on each cutting plane and are arranged on a circular arc around the optical waveguide axis (17). In the sectional plane A - A, the micro-modifications (5) are close to the cladding (12) of the optical waveguide (1) and have a large distance to the optical waveguide axis (17). In the course over the cutting planes B - B to E - E, the distance of the micro - modifications (5) to the sheath (12) of the optical waveguide (1) increases or the distance of the micro - modifications (5) to the optical waveguide axis (17) decreases. In a further advantageous embodiment of the invention, the number of micromodifications (5) arranged on a circular arc in a sectional plane decreases with the distance of the micro-modifications (5) to the optical waveguide axis (17). This is achieved by changing the time interval between two laser pulses and / or changing the rotational speed.

In a further advantageous embodiment of the invention, the arrangement of the micro-modifications in only one of the sectional planes (for example A - A) shown here takes place along the entire optical waveguide or in a plurality of circles, i. As in a sectional plane combined arrangements of sectional planes shown here (for example, A A with C C and / or E E).

FIG. 6 shows, in part a), the schematic structure of an optical waveguide with micromodifications induced by laser radiation. In sub-image b), the cross sections along the lines A - A, B - B, C - C, D - D and E - E are shown. The optical waveguide (1) is constructed by a core region (11) and a cladding region (12). By irradiation with high-energy radiation were according to the method (40) micromodifications (5) in the core region (12) of the optical waveguide (1) introduced. The micromodifications (5) on the illustrated sectional planes (A - A, B - B, C - C, D - D and E - E) are rotationally symmetrical about the optical waveguide axis (17). The number and arrangement of the micro-modifications (5) are the same in each section plane. The arrangement of the micro-modifications (5) on section plane B-B is rotated relative to the arrangement of the micro-modifications (5) on section plane A-A by an angle about the optical waveguide axis (17). This rotation of the arrangements of the micro-modifications (5) can be achieved by a rotation of the optical waveguide between the processing intervals for introducing the micro-modifications (5) into the optical waveguide (1). In the course over the cutting planes A - A to E - E, the angle of rotation of the individual cutting planes B - B to E - E increases compared to cutting plane A - A. In a further advantageous embodiment of the invention, the number of cutting planes A - A to E - E with different angles of rotation in a machining interval selected so that the arrangement of the micro-modifications (5) of the last cutting plane of the machining interval E - E would lead to the arrangement of the micro-modifications (5) on the first cutting plane A - A of the machining interval again.

FIG. 7 shows the schematic structure of an optical waveguide with micro-modifications induced by laser radiation (partial image a) and sectional images along the sectional lines A-A, B-B, C-C, D-D and E-E (partial image b)). The optical waveguide (1) is constructed by a core region (11) and a cladding region (12). By means of the irradiation according to the method (40) according to the invention, micro-modifications (5) were introduced into the core region (12) of the optical waveguide (1). The micromodifications (5) on the individual cutting planes (A - A, BB, C - C, D - D and E - E) are rotationally symmetrical about the optical waveguide axis (17). The micro-modifications (5) are arranged on the individual sectional planes AA to E-E on circular arcs around the optical waveguide axis (17). The radii of the circular arcs change in the course of the sectional planes A - A to E - E. Furthermore the arrangement of the micro - modifications (5) on a sectional plane B - B with respect to the arrangement of the micro - modifications (5) on an adjacent sectional plane A - A by an angle about the optical waveguide axis (17) is rotated. For transferring the processing steps for arranging the micro-modifications (5) on a sectional plane A - A to the processing steps for arranging the micro-modifications (5) on an adjacent cutting plane B - B is a combination of a rotation about the optical waveguide axis (17) and translation of the focused Laser beam (22) relative to the optical waveguide (1) between the processing steps for arranging the micro-modifications (5) on the adjacent cutting planes possible.

In a further advantageous embodiment of the invention, the arrangement of the micromodifications in only one of the sectional planes (for example A - A) shown here along the entire optical waveguide is rotated around the optical waveguide axis or from a combination of sectional planes, i. As in a sectional plane combined arrangements of sectional planes shown here (for example, A A with C C and / or E E). In a further advantageous embodiment of the invention, the arrangement of the micro-modifications, the arrangement is carried out in a combination of cutting planes, i. As in a sectional plane combined arrangements of cutting planes shown here (for example, A A with C C and / or E E), but with each further cutting plane according to the described pattern of the individual cutting planes changes.

FIG. 8 shows, on the basis of cross-sectional images with sections perpendicular to the optical waveguide axis (17) (partial images a) to e)) and a longitudinal section along the optical waveguide axis (17) (partial image f)), different embodiments of the invention, in which different embodiments of micro-modifications (FIG ) are shown, which were induced by laser radiation in an optical waveguide. The partial images a) and b) show micro-modifications (51, 52) with different sizes. The location of the micro-modifications can be chosen independently. The size of the micromodifications (51, 52) can be determined by the size of the focus and / or be influenced by the amount of energy introduced. The energy for the single pulse can be between 1 and 50 and the micro-modifications become larger with increasing energy, but this depends on the material of the optical waveguide and the laser beam quality. Furthermore, it is possible to arrange micro-modifications (5) so that their interfaces touch or overlap. The shape and positioning of the focus can also influence the shape of the micro-modification (52, 53). At a very long focus, micromodifications (53) are formed which have an ellipsoidal cross section with a high length to width ratio, while a short focal length results in micromodifications (52) having a small length to width ratio. With the form of the micro-modifications (53, 54, 55, 56) there is a further parameter that can be used for the production of an ordered arrangement of the micro-modifications (5). In the sub-images c) to f) different orientations of the longitudinal direction of the micro-modifications (53, 54, 55, 56) are shown. In sub-image c), the micro-modifications (53) are all oriented in the same direction. This is achieved when between the pulses of the laser radiation in the Y direction lateral translation between optical waveguide (1) and focus position is performed and due to the obliquely on the surface of the optical waveguide (1) incident focused laser beam (22) resulting refraction a suitable rotation of the focused laser beam (22) to ßi, ß ₂ , ß _{3 is} balanced. In sub-picture d), the orientations of the micro-modifications (54) are rotationally symmetrical about the optical waveguide axis (17) of the optical waveguide (1). During processing, this is achieved by rotating the optical waveguide (1) about the optical waveguide axis (17) between the laser pulses. The micro-modifications (54) are oriented so that the axis along the longitudinal direction of the micro-modification (54) through the center of the micro-modification (54) intersects the optical waveguide axis (17) of the optical waveguide (1). In sub-image e) the arrangement and orientation of the micro-modifications (5) is shown, if in addition to the processing method for field d) the focused laser radiation (22) is not introduced in the direction of the optical waveguide axis (17), but the optical waveguide (1) laterally to Fiber optic axis (17) is shifted. The Micromodifications (55) are then oriented so that an axis along the longitudinal direction of the micro-modification (55) does not intersect the optical waveguide axis (17) of the optical waveguide (1). Partial image f) shows micro-modifications (56) whose axis forms an acute angle (γ) along the longitudinal direction of the micro-modification (56) through the center of the micro-modification (56) to the optical waveguide axis (17). The angle (γ) between the orientation of the micro-modification (5) and the optical waveguide axis (17) is in a range between 10 ° and 80 °, in a preferred embodiment in a range between 20 ° and 70 ° and in a particularly preferred embodiment 30 ° and 60 °. The orientation of the angles (γ) can be made with the tip to the distal or proximal end of the optical waveguide (1). The arrangement of the micro-modifications can be designed rotationally symmetrical with respect to the optical waveguide axis (17) and become narrower towards the distal and proximal ends of the optical waveguide (1).

A movement pattern for arranging and / or orienting micro-modifications (5, 51, 52, 53, 54, 55, 56) in an optical waveguide (1) comprises one or more movements from the group comprising a translation along the spatial directions X, Y and / or Z and / or rotations about the optical waveguide axis (17) and / or an axis perpendicular to the optical waveguide axis (17). Within a movement pattern, at least one micromodification (5, 51, 52, 53, 54, 55, 56) is generated in the core (1 1) of the optical waveguide (1). Between the first execution of the movement pattern and the second and / or a subsequent repetition of the execution of the movement pattern takes place one or more movements from the group comprising a translation along the spatial directions X, Y and / or Z and / or rotations about the optical waveguide axis (17) and / or a spatial axis. In this case, the region in which micro-modifications (5, 51, 52, 53, 54, 55, 56) were introduced into the optical waveguide (1) in a first movement pattern, and the region in which micro-modifications (5, 51, 52 , 53, 54, 55, 56) were introduced into the optical waveguide (1) in a second movement pattern, overlapping. FIG. 9 shows in sub-images a) to c) the schematic structure of an optical waveguide (1) with micro-modifications induced by laser radiation (5). The marked section lines A, B and C are indicative of areas in which micro-modifications (5) have been introduced into the optical waveguide (1) as a result of a movement pattern of the focus position of the focused laser beam (22) through the optical waveguide (1). In sub-diagram a), a sequence of exemplary three different regions (A, B, C) of arrangements of micro-modifications (5) is shown, which repeat again over the length of the optical waveguide. The number of repetitions can also be multiple. The regions (A, B, C) have different arrangements of micro-modifications. In this case, a region (A, B, C) is formed by one or more of the characteristics from the group comprising the size, number, orientation, shape and / or arrangement of the micro-modifications (5, 51, 52, 53, 54, 55, 56 ) Are defined. The micro-modifications (5, 51, 52, 53, 54, 55, 56) of each region (A, B, C) are determined by a movement pattern of the focus position of the focused laser radiation (22) through the optical fiber (1) and the radiation associated therewith induced. Due to the different arrangements of the micro-modifications (5, 51, 52, 53, 54, 55, 56), the arrangements of the micro-modifications (5, 51, 52, 53, 54, 55, 56) in the regions (A, B, C ) created by different movement patterns. Between the first embodiment of a movement pattern for producing a region (A, B, C), one or more of movements of the focal position with respect to the optical waveguide (1) takes place from a group comprising the three spatial directions X, Y, and Z and the rotation α about the longitudinal axis of the optical waveguide (1) and the rotation ßi, ß ₂ , ßs about one or more axes.

In sub-image b) of FIG. 9, in a further embodiment of the invention, a further sequence of regions (A, B, C) of the same arrangement of micro-modifications (5, 51, 52, 53, 54, 55, 56) in an optical waveguide (1 ). While the first region (A) exists once, two regions follow with a second assembly (β) and three regions with a third assembly (C). In this edited fiber optic cable (1), not all regions of micromodification (5, 51, 52, 53, 54, 55, 56) arranged in a certain pattern are multiply present.

Partial image c) of FIG. 9 shows in another embodiment of the invention another possible sequence of regions (A, B, C) of the same arrangement of micro-modifications (5, 51, 52, 53, 54, 55, 56). While the first area (A) follows each area (A, B, C) which is not equal to the first area (A), the second and third areas (β, C) alternately follow the first area (A) ,

Further embodiments of the invention can be represented by arbitrary mathematical series and sequences. In another embodiment of the invention, an optical waveguide (1) according to the invention comprises more than three regions (A, B, C) with different arrangements of micro-modifications (5, 51, 52, 53, 54, 55, 56). In a preferred embodiment of the invention, the optical waveguide (1) comprises more than five regions (A, B, C), in a particularly preferred embodiment more than ten regions (A, B, C) with differently arranged micro-modifications (5, 51, 52 , 53, 54, 55, 56).

FIG. 10 shows in the partial images a) and b) the schematic structure of an optical waveguide (1) with micromodifications (5, 51, 52, 53, 54, 55, 56) induced by focused laser radiation (22). In sub-image a) is a sequence with a plurality of areas (A, B, C, D, E, F, G, H, I, J) with a different arrangement of micro-modifications (5, 51, 52, 53, 54, 55 , 56). This sequence of regions (A, B, C, D, E, F, G, H, I, J) with different arrangements of micro-modifications (5, 51, 52, 53, 54, 55, 56) is repeated n times (Partial image b)). n, m are here natural numbers, m stands for the number of repetitions of a sequence with a plurality of regions (A, B, C, D, E, F, G, H, I, J) with a different arrangement of micro-modifications ( 5, 51, 52, 53, 54, 55, 56). In a preferred embodiment of the invention, the number of repetitions of a sequence with a plurality of regions (A, B, C, D, E, F, G, H, I, J) with a different arrangement of micro-modifications (5, 51, 52 , 53, 54, 55, 56) greater than five, in a particularly preferred embodiment greater than twenty.

In a further embodiment of the invention, the arrangement of the repetitions of a sequence with a plurality of regions (A, B, C, D, E, F, G, H, I, J) with a different arrangement of micro-modifications (5, 51, 52 , 53, 54, 55, 56) alternately in the orientation of their arrangement. In a further embodiment of the invention, the arrangement of the repetitions of a sequence with a plurality of regions (A, B, C, D, E, F, G, H, I, J) with a different arrangement of micro-modifications (5, 51, 52 , 53, 54, 55, 56) a hybrid of alternating and co-alignment of their arrangement.

E N G L I S T E S E S E S Optical fibers

Core of the optical fiber

Sheath of the optical waveguide

Coating, buffer and / or further coatings of the optical fiber end cap

Proximal end of the fiber optic cable

Distal end of the fiber optic cable

Optical fiber axis

laser beam

Device for introducing micromodifications into optical waveguides

symbolized focusing optics

Focused laser beam

deflecting

focusing optics

Optical axis

spinner

Holder / guide for the optical fiber

Lateral positioning device

Vertical positioning device

Rotation of the optical fiber around the fiber optic axis

Rotation of the irradiation direction of the laser beam

Method for introducing micromodifications in optical waveguides Fixing the optical waveguide in a holder

Focusing laser radiation in a focus position 43 Moving the focus position through the fiber optic cable according to a predetermined pattern

44 Repetition of one of the movements of the focus position by the

Optical waveguide according to a predetermined pattern

5, 51, 52, 53, micro modification

54, 55, 56

γ Angle of the longitudinal alignment of the micro modifications to

Optical fiber axis

A, B, C, D, E Radial section planes through the fiber optic cable can also be inclined

F Axial section plane through the fiber optic cable

A, B, C, D, areas of the optical waveguide with arranged therein E, F, G, H, J micro-modifications

m number of repetitions of a sequence with a plurality of

Areas with different arrangement of micro-modifications n maximum number of repetitions of a sequence with a plurality of areas with different arrangement of micro-modifications

Claims

P A T E N TA N S P R O C H E

Comprising optical waveguide

a fiber-optic core,

an area in the optical waveguide,

wherein micromodifications are arranged in the region of the optical waveguide,

wherein the arrangement of the micro-modifications is ordered.

Optical waveguide according to claim 1,

characterized in that

the micro-modifications are arranged on one or more cutting planes, wherein the cutting planes lie substantially perpendicular to the optical waveguide axis and,

wherein the arrangement of the micromodifications on the section plane is defined by one or more parameters from a group of parameters comprising the symmetrical arrangement of the micro-modifications, the density of the

Section - level micromodifications, the size of the micromodifications, the distance of the micromodifications to the optical waveguide axis, the distance of the micro - modifications to each other, the alignment of the micro - modifications or other parameters that help to determine the position and distribution of the micromodules

Micro modifications or their size or external shape is described.

3. Optical waveguide according to claim 1 or 2

characterized in that

the arrangement of the micro-modifications is repeated on a first cutting plane on at least one other cutting plane.

4. Optical waveguide according to claim 3 characterized in that

the sectional plane on which the arrangement of the micro-modifications is repeated on the first cutting plane is rotated relative to the first cutting plane by an angle.

Optical waveguide according to claim 3

characterized in that

the distance between the first cutting plane and the other cutting plane on which the arrangement of the micro-modifications is repeated is greater than the extent of a micro-modification.

Optical waveguide according to one of claims 3 or 4

characterized in that

between the first cutting plane and the cutting plane on which the arrangement of the micro-modifications of the first cutting plane is repeated, there is at least one further cutting plane with micro-modifications which has a different arrangement than the first cutting plane.

Optical waveguide according to one or more of claims 2 to 6

characterized in that

the micro-modifications are arranged on the cutting plane rotationally symmetrical about the optical waveguide axis.

Optical waveguide according to one or more of claims 2 to 6

characterized in that

the micro-modifications are arranged on a hollow cone, wherein the longitudinal axis of the hollow cone lies on the optical waveguide axis.

Optical waveguide according to one or more of claims 2 to 6

characterized in that the micro-modifications are arranged on several hollow cones,

wherein the hollow cones have different diameters and,

wherein the longitudinal axes of the hollow cone lie on the optical waveguide axis.

10. Optical waveguide according to one or more of the preceding claims

characterized in that

the region in the optical waveguide in which micro-modifications are arranged is divided in the direction of the optical waveguide axis into at least two sections in which different orientations and embodiments of ordered micro-modifications are introduced.

11. Method for introducing micromodifications in optical waveguides

full

Fixation of an optical waveguide in a holder, wherein the optical waveguide and / or the holder are movably mounted,

Focusing high-energy radiation into a focal position, the focal position being positionable in the interior of the optical waveguide, the radiation being generated by a radiation source in pulsed operation,

wherein the focusing device is movably mounted for focusing the high-energy radiation

Moving the focus position through the optical waveguide characterized in that

the movement of the focal position in the interior of the optical waveguide is selected as a function of the repetition rate.

12. A method for introducing micro-modifications in optical waveguides according to claim 11

characterized in that the movement of the optical waveguide is carried out in a rotational movement.

13. A method for introducing micromodifications in optical waveguides according to claim 11 or 12

characterized in that

the focal position is continuously moved through the optical waveguide.

14. A method for introducing micro-modifications in optical waveguides according to one or more of claims 11 to 13

characterized in that

the movement of the focus position through the optical waveguide is a combination of rotational and translational motion.

15. A method for introducing micro-modifications in optical waveguides according to one or more of claims 11 to 14

characterized in that

the positioning of the focus position in the optical waveguide so with the

The repetition rate correlates to an ordered arrangement of

Micro modifications occur in the optical waveguide.

16. A method for introducing micromodifications in optical waveguides according to claim 15

characterized in that

the arrangement of the micromodifications on the cutting plane by one or more parameters from a group of parameters comprising the symmetrical arrangement of the micro-modifications, the density of the

Section-level micromodifications, the size of the micro-modifications, the distance of the micro-modifications to the fiber-optic axis, the distance of the micro-modifications to each other, the alignment of the micro-modifications or other parameters that help determine the location and distribution of

Micro modifications or their size or external shape is described.

17. A method for introducing micro-modifications in optical waveguides according to one or more of claims 11 to 16

characterized in that

the irradiation direction of the radiation onto the optical waveguide takes place at an angle between the optical waveguide axis and the irradiation direction of not equal to 90 °, in a preferred range at an angle of not equal to 90 ° +/- 5 °, in a particularly preferred range at an angle of not equal to 90 ° +/- 10 °.

18. A method for introducing micro-modifications in optical waveguides according to one or more of claims 11 to 17

characterized in that

the focusing device is additionally set in vibration in the lateral and transversal direction.