Method and device for compensating the phase disturbance of multiple wavelengths of image waveguides

Abstract

The invention relates to a method and a device for the simultaneous compensation of the phase disturbance of several wavelengths of an arrangement of electromagnetic waveguides and / or for the implementation of functions which change the propagation directions of electromagnetic radiation upon entry and / or exit into and / or from the arrangement, wherein these functions can be designed, for example, as focusing of the electromagnetic radiation to a focal point, implementation of a donut mode and / or tilting of the propagation direction of the electromagnetic radiation

Description

The invention relates to a method and an apparatus for compensating the phase interference of a plurality of wavelengths of an arrangement of electromagnetic waveguides and / or for implementing functions which change directions of propagation of electromagnetic radiation when entering and / or exiting the arrangement. The method may comprise a length change of waveguides at one end of the arrangement and / or at the other end of the arrangement such that the end forms a phase mask and / or the provision and addition of an element comprising a phase mask. The element is either a static element, the provision of which is effected by changing its surface acquisition, or an adaptive element, the provision of which is effected by changing physical variables, such as voltages, current intensities, temperatures or pulse widths, so that it forms a phase mask. Possible fields of use of the method and of the apparatus include, but are not limited to, microscopy, STED microscopy, confocal fluorescence microscopy, confocal imaging, nonlinear imaging, confocal afluorescence microscopy, optical coherence tomography, spectroscopy, multi-spectral imaging, structured illumination, optogenetics, laser ablation, optical traps, and / or endoscopy, multi-spectral endoscopy, and / or STED endoscopy.Endoscopes for imaging and illumination are used in medical technology for minimally invasive diagnostics in poorly accessible areas, for which reason it is expedient to keep their diameter as small as possible (the target size is below 0.5 mm) and their mechanical flexibility as high as possible. They also require high contrast, high spatial resolution and reliability, as well as suitable optical imaging modalities and low cost.For tissue classification in cancer diagnostics, which is based on machine learning and for network analysis in optogenetics, multi-spectral imaging with high spatiotemporal resolution is required.Multi-spectral information allows surgeons to better detect and differentiate between different fluids the health of tissue.From the prior art, borescope endoscopes are known which are based on rod and gradient index (GRIN) lenses, those whose refractive index changes as a function of the distance from the center of the lens) and which provide two-dimensional images of the intensity of electromagnetic radiation from the distal end (the application side) to the proximal end (the instrument side). Such endoscopes have rigid optical waveguide arrangements with diameters of more than 1 mm due to their function. This excludes applications such as in neurosurgery.In addition, the prior art includes camera endoscopes. These have a high flexibility, since the camera and an illumination unit are located at the distal end and only electrical signals need to be transmitted to the proximal end. The minimum endoscope diameter transmits 2 mm. Camera endoscopes also allow two-dimensional imaging and no flexible illumination. Three-dimensional imaging is enabled by stereo camera systems, but requires a higher endoscope diameter of about 10 mm. Furthermore, the electromagnetic compatibility of camera endoscopes may be deficient.In nonlinear endomicroscopy, monomode optical waveguides are generally used. Single mode optical fibers have only one local transmission channel, which is why they require complex 2D / 3D scanning optics at the distal end. As a result, the minimum diameter is limited to several millimeters. The scanning optics have a limited range of application with regard to image field diameter and wavelength and are associated with high costs. Conventional endoscopes have coherent bundles of optical fibers-also known as coherent fiber bundles (CFB)-which contain about 10,000 to 100,000 fiber cores. An ordered bundle of fibers is referred to as "coherent" if the positional relationship between each two fibers of the bundle is maintained throughout the length of the bundle. Such endoscopes allow undisturbed transmission of the two-dimensional intensity distribution in the plane of the distal fiber end surface. Planes of the inspection region can be imaged onto the distal fiber end surface by integrating rigid, macroscopic imaging optics. The relative local resolution is determined by the number of fibre cores. Distal imaging optics can increase absolute local resolution, but reduce image field diameter. The minimum endoscope diameter is limited to the millimeter range by the necessary distal imaging optics.CFB endoscopes without complex imaging optics in the distal measuring head would enable an endoscope diameter of less than 500 μm, since these would only still be limited by the fiber diameter. When a plane wave of electromagnetic radiation impinges on one end of a CFB, the phase of the radiation may have a different phase as it exits each fiber at the other end of the CFB. This is due to the scattering of the material parameters, such as the refractive index of individual fiber cores. Refractive indices are generally wavelength-dependent. The phase difference between the radiation exiting a fiber at the other end of the CFB and the phase of the exiting radiation averaged over all fibers is called phase perturbation. Each CFB may have a different phase disturbance, and therefore the phase of the electromagnetic radiation cannot be determined. Thus, only two-dimensional images with a fixed image plane are possible. For a three-dimensional imaging with high resolution, the approach is most frequently studied to measure the phase disturbance of the CFB and to compensate it by digital optical phase conjugation by means of programmable digital optical surface light modulators-also known as spatial light modulators (SLM). Surface light modulators are adaptive elements which allow phase modulation of electromagnetic radiation. For example, they can comprise arrangements of separately controllable, lowerable, raisable and / or tiltable micromirrors. Surface light modulators can also be formed as liquid crystals on a silicon substrate-also known by the term liquid crystal on silicon (LCoS). By applying an electric voltage to individual crystals of an LCoS, their refractive index can be changed. LCoS can be designed to transmit and / or reflect electromagnetic radiation.The document WO 2005 / 065 246 A2 discloses an illumination system comprising multimode optical waveguide bundles and a modulator, wherein the modulator can stretch the optical waveguides in order to reduce the spatial coherence of laser radiation and thus enable uniform illumination which is free of light granulation. The modulator may be a piezoelectric modulator. However, the device is disadvantageously not suitable for compensating a phase disturbance of optical waveguides simultaneously in a plurality of wavelengths. Multimode waveguides have modal crosstalk in comparison with monomode waveguides.U.S. Pat. No. 10,520,594 B2 describes a method and a system which make it possible to compensate for the phase disturbance of an optical waveguide bundle for in each case one wavelength by detecting the observed phase disturbance of light which is emitted by a virtual guide star at the distal end of the optical waveguide bundle at the proximal end and subjecting light of an illumination source by means of a surface light modulator to the inverse of the observed phase disturbance before it reaches the optical waveguide bundle and exits at the distal end without phase disturbance. However, the method and system described disadvantageously do not provide the possibility of simultaneously reducing the phase interference for a plurality of wavelengths.The publication EP 3 992 680 A1 describes a method and an arrangement which enable an adapted illumination of an object with light. In this case, a phase mask is produced on at least one of the fiber ends of the fiber bundle by positively locking, additive or subtractive arrangement of a flexible bundle of optical fibers, said phase mask correcting the transmission interference, so that a coherent phase arrangement is available for imaging the object. The method and the arrangement make it possible to obtain three-dimensional information about an object by means of a flexible bundle of optical fibers without integration of an imaging optical unit. The disadvantage of the method and the arrangement is that the adapted illumination with several wavelengths is not possible simultaneously.WO 2013 / 144 898 A2 relates to methods and an apparatus for imaging with multimode optical waveguides, which are based on a system for wavefront shaping, which compensates modal scrambling and the light dispersion through the multimode optical waveguide. After the multimode optical fiber is calibrated, a particular pattern is projected onto the proximal end of the waveguide to produce the desired illumination pattern at the distal end. The illumination pattern can be scanned or dynamically altered only by changing the phase pattern projected at the proximal end of the waveguide. The optical information generated from a sample is collected by the same waveguide to generate an image. The disadvantage of the method and the device is that they are not suitable for single-mode waveguides and also not for simultaneous imaging in a plurality of wavelengths.WO 2014 / 152 474 A2 describes a system and a method for imaging tissue and image guidance in luminal anatomical structures and body cavities. Embodiments relate to optical waveguides which have an additive or subtractively manufactured focusing optical lens at one end, in particular a GRIN lens, a refractive microlens or a diffractive lens. Disadvantageously, a lens is required at the distal end of the system, which increases its diameter. A disadvantage of the method is that only intensity information, but no phase information and thus no depth information is transmitted.US 2018 / 0 263 470 A1 discloses an endoscope and an imaging unit, wherein the endoscope in embodiments has a convex shape at the proximal end of an optical fiber cable in order to concentrate light at a sensor and the convex shape can be produced by an additive or a subtractive method. A disadvantage here is that it is not provided to enable imaging in more than one wavelength or one wavelength band and also not to compensate for the phase disturbance.In the publication CN 1 09 445 089 A, an apparatus for three-dimensional imaging by means of optical multimode optical waveguides is disclosed, and a method for high-speed wavefront modulation, comprising splitting a laser beam emitted by a laser into object light and reference light, carrying out a phase modulation of the object light using a digital micromirror arrangement and coupling the modulated object light into a multimode optical waveguide, recording a pattern which arises as a result of the interference of object light with the reference light, calculating a transmission matrix in accordance with the interference pattern recorded by the camera, loading a hologram onto a digital micromirror arrangement using a transmission matrix for modulating the incident light, Coupling the incident light into a multimode optical fiber and generating a focusing light spot or a three-dimensional spot scan at an output end of the multimode optical fiber, receiving light intensity information of sample reflected light or sample fluorescence by a photoelectric detector, recombination of the light intensity information according to a predetermined scan sequence to obtain an image, and synthesis in a three-dimensional direction to obtain a three-dimensional high resolution image of the sample. A disadvantage is that the phase interference cannot be compensated for simultaneously in several wavelengths.In US 2022 / 0 248 938 A1, an optical system and an imaging method are disclosed. The optical system has a multifiber conductor consisting of a plurality of optical fibers and an optical diffuser which makes it possible to image an intensity pattern onto the multifiber conductor. The intensity pattern represents phase information of light emitted from at least one three-dimensional object. The waveguide is configured to transmit the intensity pattern in the form of a plurality of image points to an evaluation system. The evaluation system is configured to generate an image of the object, wherein the generation is based on the intensity pattern transmitted by means of the waveguide. The disadvantage is that the complex-valued transfer function of the system cannot be defined and 3D imaging has to be obtained exclusively from intensity information.US 2022 / 0 019 024 A1 describes a receiving device and a method for determining transmission properties of an optical waveguide. The receiving device has a waveguide interface for receiving a mixed light beam having a plurality of modes and a mixed shifted light beam from a multimode optical fiber. The mixed and mixed shifted light beams have an associated shifted phase for each mode. The receiving device also has at least one processor for ascertaining mode information for the mixed light beam and shifted mode information for the mixed shifted light beam, wherein a trained neural network is used. Another purpose of the processor is to determine, for each mode, the respective assigned phase using the assigned phase information of the light beam and the assigned shifted phase information of the shifted light beam. It is disadvantageous that the device and the method are not suitable for simultaneously correcting the phase disturbance at a plurality of wavelengths and are also not suitable for single-mode waveguides.The document DE 10 2014 119 027 A1 relates to a device for multispot scanning microscopy, in which a sample is scanned with excitation light and emitted detection light, in particular fluorescence light, is detected. In the illumination beam path in which the excitation light is collimated, one or more phase elements configured as Dammann gratings separate the excitation light into a plurality of excitation light beams. The phases of the excitation light having a plurality of wavelengths can each be corrected using separate phase elements optimized for the respective wavelength. One aspect of this method is that the multiple spots of the individual wavelengths are merged again into a common beam path. In addition, in these variants, means, for example dielectric beam splitters, are expediently present for separating the excitation light into the portions of the individual wavelengths used. The device is disadvantageously not suitable for phase correction of light transmitted with optical waveguides.The publication DE 10 2014 119 255 A1 describes a method for light sheet microscopic examination of a sample. Here, a modulation depth of a phase selective element is set to π for a middle wavelength. A predefined phase distribution and a predefined aperture structure are impressed on the phase-selective element. Thus, it is possible to illuminate the sample with a light sheet composed of a plurality of wavelengths. The electric field of the light sheet is determined, from which a phase distribution is calculated. The phase-selective element is illuminated with illumination light and structures the latter, whereupon it is imaged into a diaphragm plane. The zeroth orders of the structured light of a plurality of wavelengths are masked, whereby a structured light sheet is produced, wherein the light sheet plane lies vertically to a focal plane of an illumination objective. The sample is illuminated with the structured light sheet and the light emitted by it is detected. The phase correction method disclosed in this publication is disadvantageously not suitable for compensating the phase disturbance of optical waveguides consisting of a plurality of optical waveguides.The prior art provides ways to compensate for the phase interference of waveguide arrangements for individual wavelengths or sequentially over time for a plurality of wavelengths. The latter can be carried out, for example, with a surface light modulator. However, this disadvantageously does not allow a high temporal resolution. The prior art does not allow to compensate the phase disturbance simultaneously for multiple wavelengths. In addition, it is not clear from the prior art how functions can be implemented which change propagation directions of electromagnetic radiation in a qualitatively different manner when entering and / or exiting the and / or the arrangement for a plurality of wavelengths.The object of the invention is to overcome the disadvantages of the prior art and to provide a method and a device which allow to simultaneously compensate the phase disturbance of an arrangement of electromagnetic waveguides for a plurality of wavelengths and / or to implement functions which change the directions of propagation of electromagnetic radiation when entering and / or exiting the arrangement. It is also an object of the invention to implement different functions of this type for different wavelengths.According to the invention, the object is achieved by a method having the features of claim 1, a device having the features of claim 13, and a use having the features of claim 20 according to the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.A first aspect of the invention relates to a method for compensating phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides j and / or for implementing a function which changes directions of propagation of electromagnetic radiation when entering and / or exiting the arrangement, comprising the steps a) providing an arrangement of electromagnetic waveguides j, wherein the arrangement comprises at least two electromagnetic waveguides j, b) modulating the electromagnetic phase interference φ ist of one or more selected waveguides j of the arrangement having a functional relationship with a reference path length, for each of the wavelengths, comprising the substeps i) measuring the electromagnetic phase interference φ ist for each of the wavelengths at each of the waveguides j, ii) determining a desired modulated phase φ soll for each of the selected waveguides j and for each of the wavelengths, wherein the desired modulated phase φ soll for each of the wavelengths is determined independently or depending on φ soll for one or more of the other wavelengths iii) determining a functional relationship between a manipulated variable x j and a phase change φ stell for each of the wavelengths and each of the waveguides j iv) defining an error function f for describing the overall deviation between a resulting phase φ res= ( φ ist+ φ stell) mod(2π) and the desired modulated phase φs oll over all wavelengths for each of the waveguides j, v) determination of the value x j_fmin of the manipulated variable x j at which the error function f assumes a minimum value for each of the waveguides j. vi) 1) provision and positioning of an element for compensating phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides and / or for implementation of a function which changes propagation directions of electromagnetic radiation when entering and / or exiting into and / or out of the arrangement, behind a first end and / or behind a second end of the arrangement, in such a way that the element along the electromagnetic propagation direction of each of the selected waveguides has the value x j_fmin of the manipulated variable x j, and / or 2) shortening and / or lengthening of the selected waveguides for compensating the phase disturbance of the selected waveguides and / or for implementing a function which changes propagation directions of electromagnetic radiation upon entering and / or exiting the arrangement, at the first end and / or at the second end of the arrangement, in such a way that the shortening and / or lengthening for each of the selected waveguides and each of the wavelengths has the value x j_fmin of the manipulated variable x j so that the arrangement of electromagnetic waveguides comprising the element and / or the shortening and / or lengthening of the selected waveguides has a resulting phase φ res_fmin for each of the wavelengths and each of the selected waveguides, at which the error function f assumes a minimum value.The electromagnetic radiation may comprise infrared radiation and / or visible light and / or ultraviolet radiation, but is not limited to the aforementioned ranges of the electromagnetic spectrum.The phase disturbance φ ist of a waveguide of the arrangement with index j at a wavelength λ can be described by the formula wherein ΔL is a deviation of an electromagnetic path length of the waveguide j at the wavelength λ from the averaged electromagnetic path length at the wavelength λ of all waveguides of the arrangement. The electromagnetic path length of the waveguide is the length of the path that would travel electromagnetic radiation in vacuum in the same time it takes for propagation through the waveguide in its rest system.Other descriptions of the phase disturbance φ ist are not excluded. In an alternative embodiment, instead of ΔL, a reference path length may be used which is the deviation of the electromagnetic path length of a waveguide from any reference length.The desired modulated phase φ soll may be determined for each of the wavelengths independently of each other or depending on the desired modulated phase φ soll for one or more of the other wavelengths, thereby making it possible to implement different functions for different wavelengths. This means, for example, that focusing of the radiation onto a focal point is desired for electromagnetic radiation of a first wavelength, while a doughnut mode is desired for radiation of a second wavelength and tilting of the propagation direction is desired for radiation of a third wavelength. Combinations of such functions, such as tilting the propagation direction and focusing the radiation of a wavelength onto a focal point, are also possible. It is also possible that φ soll for different wavelengths is selected such that the propagation direction of the radiation for each of the different wavelengths is tilted by an angle different for each of the different wavelengths and / or is focused at a focus different for each of the different wavelengths. Examples of such functions are the focusing of the radiation onto a focal point in a plane, similar to that made possible by a convex lens, the tilting of the radiation, or the generation of a doughnut mode, i.e. an annular distribution of the intensity of electromagnetic radiation in a plane.In embodiments of the method, the desired modulated phase φ soll is writable by the formula φ soll( λ,j)=(φ ist( λ,j)+φ hub( λ,j))mod(2π), where φ hu( λ,j) is a desired phase swing.A change in electromagnetic path length resulting in the desired modulated phase φ soll can be described by the formula where N is any integer.In further embodiments of the method, N is in the range between -9 and +9 inclusiveIn embodiments of the method in which it is desired to compensate the phase disturbance φ ist for a wavelength λ and a waveguide j and also implementation of an additional function φ zus is desired, the desired phase deviation φ hub( λ,j) can be determined by the formula.In further embodiments of the method in which it is only desired to compensate the phase disturbance φ ist for a wavelength λ and a waveguide j without implementing an additional function, the additional function φ zus( λ,j)=0 may be set, whereby the desired phase shift is writable by the formula φ hub( λ,j)=(-φ ist( λ,j))mod(2π), and the phase disturbance φ ist is completely compensated.Since the manipulated variable x j generally cannot be varied individually for each wavelength, it is generally not possible to achieve the ideal state φ soll= φ res for each wavelength and for each waveguide, and it is therefore necessary to minimize the error function f in order to come as close to the ideal state as possible.In preferred embodiments, the error function fby taking a square root of squares summed over all of the wavelengths of the deviation between the resulting phase φ res and the desired modulated phase φ soll oradding up, over all of the wavelengths, the amounts of deviation between the resulting phase φ res and the desired modulated phase φ soll,for each of the selected waveguides.The error function f can be determined by means of the formula or by means of the formula. Here, i represents an index of one of the wavelengths, φ solli and φ resi each represent the desired modulated phase and the resulting phase for the wavelength with index i, and the expression i≥2 represents the number of the at least two wavelengths.In preferred embodiments, the resulting value of the manipulated variable x j_fmin for each of the selected waveguides is determined by an iterative method, wherein the error function f is minimized by the iterative method.An advantage of iterative methods over computational methods is that the former are robust to model errors, while the precision of computational methods is limited by the accuracy of the mathematical models on which they are based.In preferred embodiments of the method, the resulting value of the manipulated variable x j­_fmin for each of the selected waveguides is determined by an iterative method comprising the steps of: a) measuring in a plane behind the first end or the second end of the array or the array comprising the element, intensity of electromagnetic radiation conducted through each of the selected waveguides at each of the wavelengths; b) determining the difference between the measured intensity and the intensity expected with the desired modulated phase φ soll for each of the wavelengths and each of the selected waveguides; c) changing the value of the manipulated variable x j for each of the selected waveguides; d) carrying out steps a), b) and c), until a local minimum or the global minimum of the difference between the measured intensity and the intensity expected with the desired modulated phase φ soll is determined, and setting the manipulated variable x j to the value at which the determined local minimum or global minimum is reached is determined for each of the selected waveguides.In preferred embodiments of the method, the manipulated variable x j has a functional relationship with a) a path length difference ΔS j and / or b) an electrical voltage U j and / or c) an electrical current intensity I j and / or d) a current pulse width P Ij and / or e) a voltage pulse width P Uj and / or f) a temperature T j and / or g) an SLM grayscale value.The manipulated variable x j can be set by different methods. In embodiments, if it is set by means of a shortening and / or lengthening of the selected waveguides, the manipulated variable x j has a functional relationship with a path length difference ΔS j caused by the shortening and / or lengthening. The manipulated variable x j also has a functional relationship with a path length difference ΔS j if it is set by additive or ablative production of a transmissive element.In further embodiments, if the manipulated variable x j is set by means of a surface light modulator, it can have a functional relationship with one or more physical variable or variables with which the surface light modulator is actuated. This variable or variables can be an electrical voltage U j and / or an electrical current intensity I j and / or a current pulse width P Ij and / or a voltage pulse width P Uj and / or a temperature T j or a voltage pulse width P can be a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a. In this case, this variable or these variables can also have a functional relationship with a path length difference ΔS j. This is the case, for example, if a surface light modulator has an arrangement of separately controllable, lowerable, raisable and / or tiltable micromirrors.In embodiments with surface light modulators, the manipulated variable x j can be controlled by current or voltage pulse width modulation.In further embodiments, the manipulated variable x j can be controlled by temperature modulation using surface light modulators, wherein the temperature is in a functional relationship with a current intensity and / or a voltage. Thermo-optically modulated surface light modulators can be controlled by the temperature, for example, and the temperature can in turn be controlled by an electric current intensity.In embodiments, each element of a surface light modulator may take gray scale values in the range 0 to 255.The phase change φ stell of a waveguide of the arrangement with index j at a wavelength λ can be described by the formula mod (2π), wherein n(λ,j) is the refractive index of the waveguide j at the wavelength λ for the material to which the manipulated variable x j is applied and n U( λ) is the refractive index of the medium surrounding the arrangement at the wavelength λ.Other descriptions of the phase change φ stell are not excluded.In general, different values of the manipulated variable x j may result in the same phase change φ stell for a wavelength. This principle is used by the method according to the invention in order to determine a value of the manipulated variable x j at which the resulting phase φ res= ( φ ist+ φ stell) mod(2π) comes as close as possible to the desired modulated phase φ soll for all of the wavelengths. Surprisingly, this is the case for values of the manipulated variable x j in which the phase change φ stell would lie far above 2π if it were not to comprise the modulo operator mod(2π).In preferred embodiments of the method, the functional relationships between the manipulated variable x j and the variables mentioned in a) to f) are in each case determined by calibration and / or the functional relationship between the manipulated variable x j and the path length change ΔS j comprises the difference normalized to the respective wavelength between a) the refractive index of the extended and / or shortened waveguides and / or of the element and b) the refractive index of the medium surrounding the arrangement.If the manipulated variable x j is set by a surface light modulator comprising a micromirror arrangement, the phase change φ stell can be described, for example, by the manipulated variable x j having the functional relationship x j= n U( λ) ΔS j with the path length difference ΔS j can assume values between -9 and +9, inclusive.If the manipulated variable x j is set by shortening and / or lengthening the selected waveguides and / or by a transmissive element, the phase change φ stell can be described, for example, by the manipulated variable x j having the functional relationship x j= (( n(λ,j)-n U( λ))AS j with the path length difference ΔS j can assume values between -9 and +9 inclusive.In preferred embodiments of the method, the at least two wavelengths are in a wavelength range from 100 nm to 1,000,000 nm, preferably in a wavelength range from 100 nm to 3,000 nm, particularly preferably in the range from 350 to 1,550 and / or are selected from the wavelengths 450 nm, 520 nm, 530 nm, 620 nm, 630 nm, 638 nm, 920 nm, 1,330 nm and 1,550 nm.Accordingly, in embodiments, the at least two wavelengths are in a range of the electromagnetic spectrum which extends from the UV-C radiation to the FIR radiation inclusive and in preferred embodiments from the UV-C radiation to the IR-B radiation inclusive and in particularly preferred embodiments from the UV-C radiation inclusive beyond the range of the IR-A radiation to the shortest wavelength of the IR-B radiation.In preferred embodiments of the method, the arrangement of electromagnetic waveguides is designed as an optical waveguide and / or as a bundle of optical waveguides comprising at least two optical fibers and / or as a bundle of optical fibers comprising 100 to 100,000 optical fibers.The arrangement of electromagnetic waveguides in the method is preferably designed as a bundle of monomode optical waveguides, particularly preferably as a CFB comprising a monomode optical waveguide.In embodiments of the method, the arrangement of electromagnetic waveguides is configured as a multi-core fiber comprising 100 to 100,000 monomode cores.In preferred embodiments of the method, the compensation of phase disturbance and / or the implementation of a function which changes the propagation directions of electromagnetic radiation upon entering and / or exiting the arrangement takes place by a static element which is either a transmissive or a reflective element and / or by an adaptive element which is either a transmissive or a reflective element, wherein a reflective element is positioned at a distance from the respective end of the arrangement behind which it is positioned and images a phase mask onto the respective end of the arrangement by reflecting electromagnetic radiation of the at least two wavelengths from a suitable angle of incidence. An adaptive element is expediently designed as a surface light modulator, wherein the surface light modulator is an electro-optically modulated surface light modulator or a thermo-optically modulated surface light modulator. The surface light modulator is advantageously designed as an LCoS.The distance of the reflective element from the respective end of the arrangement behind which it is positioned can be chosen as desired. The distance is preferably within the range between 10,000 times the smallest of the wavelengths and 10,000,000 times the largest of the wavelengths, particularly preferably within the range between 10,000 times the smallest of the wavelengths and 100,000 times the largest of the wavelengths.The suitable angle of incidence of electromagnetic radiation on the reflective element is above 0° and below 90°, preferably between 10° and 80°.In preferred embodiments of the method,extending selected waveguides for compensating phase interference and / or for implementing a function which changes propagation directions of electromagnetic radiation upon entering and / or exiting the arrangement by additive manufacturing onto the selected waveguides at the first end and / or at the second end of the arrangement and / orshortening selected waveguides for compensating the phase disturbance and / or for implementing a function which changes propagation directions of electromagnetic radiation when entering and / or exiting the arrangement by laser ablation and / or by electron beam ablation of the selected waveguides at the first end and / or the second end of the arrangement and / orproviding the element at the first end and / or at the second end of the arrangement by additive manufacturing on an element blank and / or by laser ablation and / or by electron beam ablation of an element blank and / orproviding the element at the first end and / or the second end of the respective waveguide by manufacturing meta-optics, wherein the meta-optics are characterized in that they have structures whose dimensions are smaller than the smallest of the wavelengths.In the context of the invention, the element blank is referred to as the element in the state in which it is located temporally before the additive manufacturing and / or the laser ablation and / or the electron beam ablation, by means of which it is made as an element for compensating phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides and / or for implementing a function which propagation directions of electromagnetic radiation are manufactured when entering and / or exiting into and / or out of the arrangement.In preferred embodiments of the method, the additive manufacturing comprises one-photon polymerization and / or two-photon polymerization and / or multi-photon polymerization.In preferred embodiments of the method, substep b) i) of the method according to the invention takes place either by means of white light interferometry or by means of digital holography and / or a phase retrieval method.Digital holography and the phase retrieval method can be used together.In further embodiments, the digital holography is formed as off-axis holography using a Mach-Zehnder interferometer.A further aspect of the invention relates to a device for compensating electromagnetic phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides j and / or for implementing a function which changes propagation directions of electromagnetic radiation when entering and / or exiting into and / or out of the arrangement, comprising an arrangement of at least two electromagnetic waveguides, characterized in thatthe device comprises an element for compensating phase interference and / or for implementing a function which changes propagation directions of electromagnetic radiation when entering and / or exiting the arrangement and / or is modulated at a first end and / or a second end of the arrangement in such a way that the element has a manipulated variable x j_fmin along the electromagnetic propagation direction of one or more selected waveguides, and / orthe device is modulated in that the arrangement has a shortening and / or extension of the selected waveguides, wherein the shortening and / or extension has a control variable x j_fmin for each of the selected waveguides,wherein the manipulated variable x j_fmin is determined by substeps b) i) to v) of the method according to the invention.The phase distortion φ ist of a waveguide of the arrangement with index j at a wavelength λ can be described by the formula wherein ΔL is a deviation of an electromagnetic path length of the waveguide j at the wavelength λ from the averaged electromagnetic path length at the wavelength λ of all waveguides. The electromagnetic path length of the waveguide is the length of the path that would travel electromagnetic radiation in vacuum in the same time it takes to traverse the waveguide in its rest system.Other descriptions of the phase disturbance φ ist are not excluded. In an alternative embodiment, instead of ΔL, a reference path length may be used which is the deviation of the electromagnetic path length of a waveguide from any reference length.The desired modulated phase φ soll may be determined for each of the wavelengths independently of each other or depending on the desired modulated phase φ soll for one or more of the other wavelengths, thereby making it possible to implement different functions for different wavelengths. This means that for electromagnetic radiation of a first wavelength, a focusing of the radiation onto a focal point is desired, while for radiation of a second wavelength, a doughnut mode is desired and for radiation of a third wavelength, a tilting of the propagation direction is desired. Combinations of such functions, such as tilting the propagation direction and focusing the radiation of a wavelength onto a focal point, are also possible. It is also possible that φs oll for different wavelengths is selected such that the propagation direction of the radiation for each of the different wavelengths is tilted by an angle different for each of the different wavelengths and / or is focused at a focus different for each of the different wavelengths. Examples of such functions are the focusing of the radiation onto a focal point in a plane, similar to that made possible by a convex lens, the tilting of the radiation, or the generation of a doughnut mode, i.e. an annular distribution of the intensity of electromagnetic radiation in a plane.In embodiments of the device, the desired modulated phase φ soll is writable by the formula φ soll( λ,j) = (φ ist( λ,j) + φ hub( λ,j))mod(2π), where φ hub( λ,j) is a desired phase swing.A change in electromagnetic path length resulting in the desired modulated phase φ soll can be described by the formula where N is any integer.In further embodiments of the device, N is in the range between -9 and +9 inclusive.In embodiments of the device configured to compensate the phase disturbance φ ist for a wavelength λ and a waveguide j and also implement an additional function φ zus the desired phase shift φ hub( λ,j) may be described by the formula.In further embodiments of the apparatus configured to compensate the phase disturbance φ ist for a wavelength λ and a waveguide j without implementing an additional function, the additional function φ zus( λ,j)=0 may be set, whereby the desired phase shift is writable by the formula φ hu( λ,7)=(-φ ist( λ,j))mod(2π), and the phase disturbance φ ist is completely compensated.Since the manipulated variable x j generally cannot be varied individually for each wavelength, it is generally not possible to achieve the ideal state φ soll= φ res for each wavelength and for each waveguide, and it is therefore necessary to minimize the error function f in order to come as close to the ideal state as possible.In preferred embodiments of the device, the manipulated variable x j has a functional relationship with a) a path length difference ΔS j and / or b) an electrical voltage U j and / or c) an electrical current intensity I j and / or d) a current pulse width P Ij and / or e) a voltage pulse width P Uj and / or f) a temperature T j and / or g) an SLM grayscale value.The manipulated variable x j can be set by different methods.In embodiments, if it is set by means of a shortening and / or lengthening of the selected waveguides, the manipulated variable x j has a functional relationship with a path length difference ΔS j caused by the shortening and / or lengthening. The manipulated variable x j also has a functional relationship with a path length difference ΔS j if it is set by additive or ablative production of a transmissive element.In further embodiments, if the manipulated variable x j is set by means of a surface light modulator, it can have a functional relationship with one or more physical variable or variables with which the surface light modulator is actuated. This variable or variables can be an electrical voltage U j and / or an electrical current intensity I j and / or a current pulse width P Ij and / or a voltage pulse width P Uj and / or a temperature T j or a voltage pulse width P can be a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a variable value of a. In this case, this variable or these variables can also have a functional relationship with a path length difference ΔS j. This is the case, for example, if a surface light modulator has an arrangement of separately controllable, lowerable, raisable and / or tiltable micromirrors.In embodiments with surface light modulators, the manipulated variable x j can be controlled by current or voltage pulse width modulation.In further embodiments, the manipulated variable x j can be controlled by temperature modulation using surface light modulators, wherein the temperature is in a functional relationship with a current intensity and / or a voltage. Thermo-optically modulated surface light modulators can be controlled by the temperature, for example, The temperature can in turn be controlled by an electric current.The phase change φ stell of a waveguide of the arrangement with index j at a wavelength λ can be described by the formula wherein n(λ,j) is the refractive index of the waveguide j at the wavelength λ for the material to which the manipulated variable x j is applied and n U( λ) is the refractive index of the medium surrounding the arrangement at the wavelength λ.Other descriptions of the phase change φ stell are not excluded.In general, different values of the manipulated variable x j may result in the same phase change φ stell for a wavelength. This principle is used by the device according to the invention in order to make possible a value of the manipulated variable x j at which the resulting phase φ res= ( φ ist+ φ stell) mod(2π) is as close as possible to the desired modulated phase φ soll for all of the wavelengths. Surprisingly, this is the case for values of the manipulated variable x j in which the phase change φ stell would lie far above 2π if it were not to comprise the modulo operator mod(2π).In preferred embodiments of the device, the at least two wavelengths are in a wavelength range between 100 nm and 1,000,000 nm, advantageously in a wavelength range from 100 nm to 3,000 nm, particularly advantageously in the range from 350 nm to 1,550 nm and / or are selected from the wavelengths 450 nm, 520 nm, 530 nm, 638 nm, 920 nm, 1,330 nm and 1,550 nm.Accordingly, in embodiments, the at least two wavelengths are in a range of the electromagnetic spectrum which extends from the UV-C radiation to the FIR radiation inclusive and in preferred embodiments from the UV-C radiation to the IR-B radiation inclusive and in particularly preferred embodiments from the UV-C radiation inclusive beyond the range of the IR-A radiation to the shortest wavelength of the IR-B radiation.In preferred embodiments of the device, the arrangement of electromagnetic waveguides is designed as an optical waveguide, and / or as a bundle of optical waveguides comprising at least two optical fibers and / or as a bundle of optical fibers comprising 100 to 100,000 optical fibers.The arrangement of electromagnetic waveguides comprised by the device according to the invention is preferably embodied as a bundle of monomode optical waveguides, particularly preferably as a CFB comprising a monomode optical waveguide.In further embodiments of the method, the arrangement of electromagnetic waveguides is configured as a multi-core fiber comprising 100 to 100,000 monomode cores.In preferred embodiments of the device comprising an element, the element is a static element which is either a transmissive or a reflective element and / or an adaptive element which is either a transmissive or a reflective element, wherein a reflective element is positioned at a distance from the respective end of the arrangement behind which it is positioned and, by reflection of electromagnetic radiation of the at least two wavelengths from a suitable angle of incidence, images a phase mask onto the respective end of the arrangement, wherein the adaptive element is designed as a surface light modulator.An adaptive element is expediently designed as a surface light modulator, wherein the surface light modulator is an electro-optically modulated surface light modulator or a thermo-optically modulated surface light modulator. The surface light modulator is advantageously designed as an LCoS.The distance of the reflective element from the respective end of the arrangement behind which it is positioned can be chosen as desired. The distance is preferably within the range between 10,000 times the smallest of the wavelengths and 10,000,000 times the largest of the wavelengths, particularly preferably within the range between 10,000 times the smallest of the wavelengths and 100,000 times the largest of the wavelengths.The suitable angle of incidence of electromagnetic radiation on the reflective element is above 0° and below 90°, preferably between 10° and 80°.In preferred embodiments of the device comprising an element, the element is a static element, wherein the element has a path length difference ΔS j with respect to a reference length along the electromagnetic propagation direction of each of the selected waveguides.Any desired reference length can be selected. The path length difference ΔS j for each of the selected waveguides is realized by a surface acquisition of the element embodied as a phase mask.In embodiments of the device, the material of the element for compensating the phase disturbance of the selected waveguides comprises meta-optics at the first end and / or at the second end of the respective waveguides, the meta-optics being characterized in that they have structures whose dimensions are smaller than the smallest of the wavelengths.In principle, metaoptics can be provided which have structures which are characterized in that the functional relationship between their refractive indices and the wavelength of electromagnetic radiation is freely selectable. Unlike conventional materials transparent to electromagnetic radiation, this functional relationship is not necessarily representable by the Sellmeier equation. By means of freely selectable refractive indices, it is possible to equate the resulting phase φ res to the desired modulated phase φ soll for each of the wavelengths and thus completely cancel out the phase disturbance for each of the wavelengths.A further aspect of the invention relates to a use• the method according to the invention and / or its embodiments and / or• the device according to the invention and / or its embodimentsin microscopy, STED microscopy, confocal fluorescence microscopy, confocal imaging, nonlinear imaging, confocal afluorescence microscopy, optical coherence tomography, spectroscopy, multi-spectral imaging, structured illumination, optogenetics, laser ablation, optical traps, needle biopsy and / or in endoscopy, multi-spectral endoscopy and / or STED endoscopy.The invention is not limited to the embodiments shown and described, but also encompasses all embodiments having the same effect within the meaning of the invention. Furthermore, the invention is also not restricted to the specifically described combinations of features, but rather can also be defined by any other desired combination of specific features of all individual features disclosed overall, provided that the individual features are not mutually exclusive, or a specific combination of individual features is not explicitly excluded.Exemplary EmbodimentThe invention will be explained in more detail below with reference to an exemplary embodiment. The exemplary embodiment relates to an embodiment of the method according to the invention and of the device according to the invention and is intended to describe the invention without limiting it.An endoscope is provided which comprises a Sumita HDIG single mode CFB having 10,000 fiber cores. The diameter of the endoscope is 385 μm and is limited only by the CFB.FIG. 18 schematically illustrates a structure for detecting and compensating for phase distortion of a CFB. The phase distortion φ ist of each fiber core of the monomode CFB is measured sequentially in the wavelengths 450 nm, 520 nm and 638 nm by means of off-axis holography using a Mach-Zehnder interferometer, the structure comprising components known to the skilled person, namely a laser, a diaphragm (B1), beam splitters (BS1 and BS2), lenses (L1, L2, L3. L4, L5 and L6), a mirror (M1), a microscope objective (MO1), polarization filters (PF1, PF2 and PF3) and a fiber-coupled beam splitter (Y 50:50) which splits radiation into two components in the intensity ratio 50:50. For this purpose, the proximal end of the monomode CFB is imaged on a camera (CAM1). Light from the proximal end of the multicore fiber impinges on a reflective surface light modulator (SLM) of the type Holoeye Pluto-NIR-011 in the switched-off state and is reflected by the latter in the direction of the camera (CAM1). In this case, the proximal end of the CFB and the surface light modulator (SLM) are imaged sharply by the camera (CAM1). As an alternative to the switched-off state, the surface light modulator can also be in the switched-on state, but have the same grayscale value for all fiber cores.For each fiber core of the CFB, all gray scale values of the surface light modulator (SLM) are set sequentially from 0 to 255. For each fiber core, the resulting phase φ res is measured at each gray level value in each of the three wavelengths and each measurement value is stored. Also, for each fiber core and gray level value of the spatial light modulator (SLM), the sum of the squares of the resulting phase φ res over all three wavelengths is determined and stored. The square root of the sum of the squares of the resulting phase φ res over all three wavelengths is the error function f.The phase disturbance is compensated by setting, at the surface light modulator (SLM), for each fiber core of the CFB, the gray scale value of the surface light modulator (SLM) for which the error function f assumes the smallest value.FIG. 19 schematically illustrates a structure for imaging, on a camera (CAM2), a USAF resolution test panel illuminated with an RGB LED (red-green-blue light emitting diode) emitting at wavelengths 450 nm, 520 nm and 638 nm, with the same CFB and the SLM previously set for compensating the phase disturbance. In this case, the USAF resolution test panel is sharply imaged by the camera (CAM2). The mapping of the USAF resolution test chart in the three wavelengths is shown in the fourth row of Fig. 17.The invention is explained in more detail with reference to drawings. Figure shows FIG. 1 shows a schematic illustration of electromagnetic radiation without phase interference ( 1) entering an arrangement ( 2) of electromagnetic waveguides ( 3) and of electromagnetic radiation ( 4) emerging from the arrangement ( 2) and having phase interference φ ist , FIG. 2 shows the resulting phases φ res-rot(5), φ res-grün(6) and φ res-blau(7) of an exemplary waveguide of an embodiment of the method having a surface light modulator (SLM), in the wavelengths 638 nm, 520 nm and 450 nm, and the error function (8), in each case as a function of the manipulated variable x j, wherein the manipulated variable x j is designed as an SLM grayscale value in this embodiment and no implementation of an additional function φ zus is present, FIG. 3 shows a schematic illustration of electromagnetic radiation without phase disturbance (1) entering an arrangement (2) of electromagnetic waveguides (3), wherein the arrangement has at one end an element (9) having an additively manufactured phase mask for compensating the phase disturbance φ ist and implementing an additional function φ zus wherein the additional function φ zus is the focusing of the emerging electromagnetic radiation (10) onto a focal point, FIG. 4 shows a schematic illustration of electromagnetic radiation without phase disturbance (1) entering an arrangement (2) of electromagnetic waveguides (3), wherein the arrangement has an element (11), having an additively manufactured phase mask, for compensating the phase disturbance φ ist at one end and of emerging electromagnetic radiation (12), the phase disturbance of which is compensated, FIG. 5 shows a schematic illustration of electromagnetic radiation without phase disturbance (1) incident on a surface light modulator (SLM), wherein the surface light modulator (SLM) is set such that the radiation (13) reflected by it has a phase deviation φ hub( λ,j)=((-φ ist( λ,j))+φ zus( λ,j))mod (2π), as a result of which the phase disturbance φ ist of the radiation (12) is compensated for when it exits from an arrangement (2) of electromagnetic waveguides (3) and an additional function φ zus is implemented, wherein the additional function φ zus is the focusing of the exiting electromagnetic radiation (10) onto a focal point, FIG. 6 is a schematic illustration of a cross section of an arrangement of electromagnetic waveguides (j), FIG. 7 is a schematic illustration of a cross section of an end of an arrangement of electromagnetic waveguides, wherein the individual circles represent individual waveguides and the grey levels of which represent the values of the phase disturbance φ ist( λ 1, j) in a wavelength λ 1 , FIG. 8 is a schematic illustration of a cross section of an end of an arrangement of electromagnetic waveguides, wherein the individual circles represent individual waveguides and the grey levels of which represent the values of the phase disturbance φ ist( λ 2, j) in a wavelength λ 2 , FIG. 9 is a schematic representation of a cross section of one end of an array of electromagnetic waveguides, wherein the individual circles represent individual waveguides and their gray scales represent the values of the desired phase shift φ hub( λ 1, j))=(-φ ist( λ 1, j))mod(2π) in a wavelength λ 1 , FIG. 10 is a schematic representation of a cross section of one end of an array of electromagnetic waveguides, wherein the individual circles represent individual waveguides and their gray scales represent the values of the desired phase shift φ hub( λ 2, j)=(-φ ist( λ 2, j))mod(2π) in a wavelength λ 2 , FIG. 11 is a schematic illustration of a cross-section of an end of an array of electromagnetic waveguides, wherein the individual circles represent individual waveguides and their gray scales represent the values of the desired modulated phase φ soll( λ 1, j)=(φ ist( λ 1, j)+φ hub( λ 1, j))mod (2π) with phase deviation φ hub( λ 1, j)=(-φ ist( λ 1, j)+φzus(λ1,j))mod (2π) in a wavelength λ1, wherein the additional function φ zus( λ 1, j) corresponds to focusing electromagnetic radiation of the wavelength λ 1 onto a focal point, FIG. 12 is a schematic illustration of a cross-section of an end of an array of electromagnetic waveguides, wherein the individual circles represent individual waveguides and their gray scales represent the values of the desired modulated phase φ soll( λ 2, j)=(φ ist( λ 2, j)+φ hub( λ 2, j))mod (2π) with phase deviation φ hub( λ 2, j)=(-φ ist( λ 2, j)+φzus(λ2,j))mod (2π) in a wavelength λ1, wherein the additional function φ zus( λ 2, j) corresponds to a doughnut mode of electromagnetic radiation of the wavelength λ 2, FIG. 13 shows an intensity distribution of focused electromagnetic radiation of the wavelength λ 1 in the focal plane (BEF), FIG. 14 shows an intensity distribution of focused electromagnetic radiation of the wavelength λ 1 in a plane orthogonal to the focal plane (BEF), on which the focal point lies, FIG. 15 shows an intensity distribution of electromagnetic radiation of the wavelength λ 1 in a doughnut mode in the focal plane (BED), FIG. 16 shows an intensity distribution of electromagnetic radiation of the wavelength λ 2 of a doughnut mode in a plane orthogonal to the focal plane (BED), on which the focal point lies, FIG. 17 shows images in the wavelengths 450 nm, 520 nm, and 638 nm of a part of a USAF resolution test panel illuminated with the wavelengths 450 nm, 520 nm, and 638 nm, respectively, by means of an arrangement of optical waveguides, wherein for illuminations in each of the three wavelengths the USAF resolution test panel is depicted with a compensation of the phase disturbance φ ist optimized for each of the three wavelengths, and a compensation of the phase disturbance in which the error function f is minimized (line RGB), wherein it is apparent to the observer that for the simultaneous imaging of the USAF resolution test panel with all waveguides of the arrangement in all three wavelengths the variant in which the error function f is minimized is more suitable than the three other variants, FIG. 18 shows an embodiment of the device which is configured for the method of determining the phase disturbance φ ist of a CFB of the type Sumita HDIG by off-axis holography using a Mach-Zehnder interferometer, wherein the proximal end of the CFB is imaged onto a camera CAM 1, FIG. 19 shows an embodiment of the apparatus designed for the method of imaging a USAF resolution test chart in which aperture B1 blocks higher order diffractions.Reference numerals denote reference numerals1 Incoming electromagnetic radiation without phase disturbance 2 Arrangement of electromagnetic waveguides 3 Electromagnetic waveguides 4 Outgoing electromagnetic radiation having phase disturbance 5 Resultant phase φ res-rot for λ = 638 nm as a function of the SLM gray value 6 Resultant phase φ res-grün for λ = 520 nm as a function of the SLM gray value 7 Resultant phase φ res-blau for λ = 450 nm as a function of the SLM gray value 8 Error function f in a case in which 9 element having an additive-manufactured phase mask for compensating the phase disturbance and implementing a function which focuses propagation directions of electromagnetic radiation on emerging from the arrangement to a focal point 10 Outgoing electromagnetic radiation, the phase disturbance of which is compensated for and which is focused on a focal point 11 An additively manufactured phase mask for compensating the phase disturbance 12 emerging electromagnetic radiation, the phase disturbance of which is compensated for 13 Radiation having a phase deviation φ hub( λ,j)=((-φ ist( λ,j))+φ zus( λ,j))mod (2π) reflected by the surface light modulator, which compensates the phase disturbance of the electromagnetic waveguide and implements an additional function, which results in the focusing on a focal point BEF focal plane BED shown in FIG. 12 focal plane of the doughnut mode B1 aperture BS1 shown in FIG. 14, Beam splitter CAM1, CAM2 Camera CFB Coherent bundle of optical fibers L1, L2, L3, L4, L5, L6 Lens M1 Mirror MO1 Microscope objective PF1, PF2, PF3 Polarization filter Test chart USAF Resolution test panel SLM Surface light modulator Y 50:50 Fiber-coupled beam splitter

Claims

Method for compensating phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides j and / or for implementing a function which changes directions of propagation of electromagnetic radiation when entering and / or exiting the arrangement, comprising the steps a. providing an arrangement of electromagnetic waveguides j, wherein the arrangement comprises at least two electromagnetic waveguides j, b. modulating the electromagnetic phase interference φ ist of one or more selected waveguides j of the arrangement having a functional relationship with a reference path length, for each of the wavelengths, comprising the substeps i) measuring the electromagnetic phase interference φ ist for each of the wavelengths at each of the waveguides j, ii) determining a desired modulated phase φ soll for each of the selected waveguides j and for each of the wavelengths, wherein the desired modulated phase φ soll is determined for each of the wavelengths independently of one another or is determined depending on φ soll for one or more of the other wavelengths iii) determining a functional relationship between a manipulated variable x j and a phase change φ stell for each of the wavelengths and each of the waveguides j iv) defining an error function f for describing the total deviation between a resulting phase φ res= ( φ ist+ φ stell) mod(2π) and the desired modulated phase φ soll over all wavelengths for each of the waveguides j, v) determination of the value x j_fmin of the manipulated variable x j at which the error function f assumes a minimum value for each of the waveguides j. vi) 1. provision and positioning of an element for compensating phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides and / or for implementation of a function which changes propagation directions of electromagnetic radiation upon entry and / or exit into and / or out of the arrangement, behind a first end and / or behind a second end of the arrangement, in such a way that the element along the electromagnetic propagation direction of each of the selected waveguides has the value x j_fmin of the manipulated variable x j, and / or 2. shortening and / or lengthening of the selected waveguides for compensating the phase disturbance of the selected waveguides and / or for implementing a function which changes propagation directions of electromagnetic radiation upon entering and / or exiting the arrangement, at the first end and / or at the second end of the arrangement, such that the shortening and / or lengthening for each of the selected waveguides and each of the wavelengths has the value x j­_fmin of the manipulated variable x j such that the arrangement of electromagnetic waveguides comprising the element and / or the shortening and / or lengthening of the selected waveguides has a resulting phase φ res_fmin for each of the wavelengths and each of the selected waveguides, at which the error function f assumes a minimum value.Method according to claim 1, characterized in that the error function f is determined - by taking a square root of squares summed over all of the wavelengths of the deviation between the resulting phase φ res and the desired modulated phase φ soll or - by summing over all of the wavelengths the amounts of deviation between the resulting phase φ res and the desired modulated phase φ soll, for each of the selected waveguides.Method according to claim 1 or 2, characterised in that the resulting value of the manipulated variable x j_fmin for each of the selected waveguides is determined by an iterative method, wherein the error function f is minimized by the iterative method.A method according to claim 3, characterized bythe steps of a) measuring in a plane behind the first end or the second end of the array or the array comprising the element, intensity of electromagnetic radiation passed through each of the selected waveguides in each of the wavelengths, b) determining the difference between the measured intensity and the expected intensity with the desired modulated phase φ soll for each of the wavelengths and each of the selected waveguides, c) changing the value of the manipulated variable x j for each of the selected waveguides, d) carrying out the steps a), b) and c), until a local minimum or the global minimum of the difference between the measured intensity and the intensity expected with the desired modulated phase φ soll is determined, and setting the manipulated variable x j to the value at which the determined local minimum or global minimum is reached, for each of the selected waveguides.Method according to one of the preceding patent claims, characterized in that the manipulated variable x j has a functional relationship with a) a path length difference ΔS j and / or b) an electrical voltage U j and / or c) an electrical current intensity I j and / or d) a current pulse width P Ij and / or e) a voltage pulse width P Uj and / or f) a temperature T j and / or g) an SLM gray value.Method according to claim 5, characterised in that the functional relationships between the manipulated variable x j and the variables mentioned in a) to f) are each determined by calibration and / or the functional relationship between the manipulated variable x j and the path length change ΔS comprises the difference normalized to the respective wavelength between a) the refractive index of the extended and / or shortened waveguides and / or of the element and b) the refractive index of the medium surrounding the arrangement.Method according to one of the preceding patent claims, characterized in that the at least two wavelengths are in a wavelength range from 100 nm to 1,000,000 nm, preferably in a wavelength range from 100 nm to 3,000 nm, particularly preferably in the range from 350 to 1,550, and / or are selected from the wavelengths 450 nm, 530 nm, 620 nm, 630 nm, 638 nm, 920 nm, 1,330 nm and 1,550 nm.Method according to one of the preceding patent claims, characterized in that the arrangement of electromagnetic waveguides is designed as an optical waveguide and / or as a bundle of optical waveguides comprising at least two optical fibers and / or as a bundle of optical fibers comprising 100 to 100,000 optical fibers.Method according to one of the preceding patent claims, characterized in that the compensation of phase interference and / or the implementation of a function which changes the propagation directions of electromagnetic radiation when entering and / or exiting the arrangement is effected by a static element which is either a transmissive or a reflective element and / or by an adaptive element which is either a transmissive or a reflective element, wherein a reflective element is positioned at a distance from the respective end of the arrangement behind which it is positioned and, by reflecting electromagnetic radiation of the at least two wavelengths from a suitable angle of incidence, images a phase mask onto the respective end of the arrangement, wherein the adaptive element is designed as a surface light modulator.Method according to one of the preceding patent claims, characterized in that - the extension of selected waveguides for compensating phase interference and / or for implementing a function which changes directions of propagation of electromagnetic radiation when entering and / or exiting into and / or out of the arrangement is effected by additive manufacturing onto the selected waveguides at the first end and / or at the second end of the arrangement, and / or in that - the shortening of selected waveguides for compensating phase interference and / or for implementing a function, which propagation directions of electromagnetic radiation when entering and / or exiting into and / or from the arrangement change by laser ablation and / or by electron beam ablation of the selected waveguides at the first end and / or the second end of the arrangement and / or in that - the provision of the element at the first end and / or at the second end of the arrangement is effected by additive manufacturing on an element blank and / or by laser ablation and / or by electron beam ablation of an element blank and / or - the provision of the element at the first end and / or the second end of the respective waveguide is effected by manufacturing meta-optics, wherein the meta-optics end are characterized in that they have structures whose diameters are smaller than the smallest of the wavelengths.Method according to claim 10, characterised in that the additive manufacturing comprises one-photon polymerisation and / or two-photon polymerisation and / or multi-photon polymerisation.Method according to one of the preceding patent claims, characterized in that substep b) i) takes place either by means of white light interferometry or by means of digital holography and / or a phase retrieval method.Device for compensating electromagnetic phase interference of at least two wavelengths of an arrangement of electromagnetic waveguides j and / or for implementing a function which changes directions of propagation of electromagnetic radiation when entering and / or exiting into and / or from the arrangement, comprising an arrangement of at least two electromagnetic waveguides, characterized in that - the device has an element for compensating phase interference and / or for implementing a function which changes directions of propagation of electromagnetic radiation when entering and / or exiting into and / or from the arrangement and / or is modulated by a first end and / or a second end of the arrangement in such a way that the element has a manipulated variable x j_fmin along the electromagnetic direction of propagation of one or more selected waveguides, and / or - the device is modulated thereby, the arrangement having a shortening and / or lengthening of the selected waveguides, wherein the shortening and / or lengthening has a manipulated variable x j_fmin for each of the selected waveguides, wherein the manipulated variable x j_fmin is determined by substeps b) i) to v) of the method according to one of Patent Claims 1 to 12.Device according to claim 13, characterised in that the control variable x j has a functional relationship with a path length difference ΔS j and / or b) of an electrical voltage U j and / or c) of an electrical current intensity I j and / or d) of a current pulse width P Ij, and / or e) of a voltage pulse width P Uj and / or f) of a temperature T j and / or g) of an SLM grey value.Device according to claim 13 or 14, characterised in that the at least two wavelengths are in a wavelength range between 100 nm and 1,000,000 nm, preferably in a wavelength range from 100 nm to 3,000 nm, particularly preferably in the range from 350 nm to 1,550 nm and / or are selected from the wavelengths 450 nm, 520 nm, 530 nm, 638 nm, 920 nm, 1,330 nm and 1,550 nm.Device according to one of Patent Claims 13 to 15, characterized in that the arrangement of electromagnetic waveguides is designed as an optical waveguide, and / or is designed as a bundle of optical waveguides comprising at least two optical fibers and / or as a bundle of optical fibers comprising 100 to 100,000 optical fibers.Device according to one of Patent Claims 13 to 16, characterized in that the element is a static element which is either a transmissive or a reflective element and / or an adaptive element which is either a transmissive or a reflective element, wherein a reflective element is positioned at a distance from the respective end of the arrangement behind which it is positioned and, by reflection of electromagnetic radiation of the at least two wavelengths from a suitable angle of incidence, images a phase mask onto the respective end of the arrangement, wherein the adaptive element is designed as a surface light modulator.Device according to any of claims 13 to 17, characterized in that the element is a static element, the element having a path length change ΔS j with respect to a reference path length along the electromagnetic propagation direction of each of the selected waveguides.Device according to any one of claims 13 to 18, characterised in that the material of the phase disturbance compensation element of the selected waveguides comprises meta-optics at the first end and / or at the second end of the respective waveguides, the meta-optics being characterised in that they comprise structures whose diameters are smaller than the smallest of the wavelengths.Use of a method according to claims 1 to 12 and / or of a device according to claims 13 to 19 in microscopy, STED microscopy, confocal fluorescence microscopy, confocal imaging, non-linear imaging, confocal afluorescence microscopy, optical coherence tomography, spectroscopy, multi-spectral imaging, structured illumination, optogenetics, laser ablation, optical traps, and / or in endoscopy, multi-spectral endoscopy, and / or STED endoscopy.

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