remote sensor device

Abstract

Remote sensing device comprising: a primary light source for emitting primary light (3) with a first wavelength, an optical waveguide (1) with a proximal end and a distal end, configured for transmitting the primary light (3) from the proximal end to the distal end and for transmitting secondary light (4) with a second wavelength caused at the distal end by the primary light (3) back to the proximal end, a light receiving / emitting unit (2) arranged at the distal end of the optical waveguide (1) for receiving the primary light (3) from the distal end and for emitting the secondary light (4) to the distal end of the optical waveguide (1), and a secondary light receiver arranged at the proximal end of the optical waveguide (1) for receiving the secondary light (4) from the proximal end of the optical waveguide (1), wherein the optical waveguide (1) has a numerical aperture greater than 0.5.wherein the optical waveguide (1) comprises a plurality of structural elements (10), each extending from the proximal to the distal end and partially across the cross-section of the optical waveguide, such that a plurality of cross-sectional regions are defined in the cross-section of the waveguide, each corresponding to the cross-section of a single structural element (10), and wherein the structural elements (10), in particular their cross-sectional regions, are arranged non-uniformly to effect a transverse Anderson localization of the primary light and the secondary light.

Description

The invention relates to a remote sensing device comprising an optical waveguide with a proximal and a distal end, a primary light source arranged at the proximal end, and a unit arranged at the distal end for receiving the primary light and emitting secondary light for transmission back to the proximal end. A light-receiving / emitting unit or sensor unit located at the distal end can, in principle, serve to or contribute to the detection of various measured quantities. For example, the measurement of magnetic fields, conductivities, temperatures, or oxygen saturations can be enabled or supported. Depending on the application, different requirements may apply to the optical fiber. These requirements include, for example, the diameter or materials of the light-guiding cores or surrounding cladding layers, or the properties of a bundle, such as a bundle of individual fibers or tubes with different refractive indices. Depending on the application, certain parameters must also be considered, such as flexibility and dimensions, with miniaturization often being desirable in some fields, particularly in medical applications. Document US 5,191,388 A describes a device for analyzing particles in a suspension, wherein an end face of a fiber bundle is exposed to the suspension in order to observe it. Document WO 2012 087 754 A1 describes a fiber optic probe which has a fiber for illumination, a fiber for analysis and a spherical lens. Document CN 1 11 552 026 A describes an optical system for photodynamic therapy, using an Anderson waveguide to transmit image information of the tissue being observed. Document US 11 321 837 B2 describes an imaging system in which images are taken from a cell sample and transmitted via an Anderson localizing optical fiber. Document DE 36 50 688 T2 describes a laser catheter with multiple optical waveguides to guide laser light and thus irradiate tissue. Documents DE 10 2020 116 444 A1 and WO 2021 259 926 A1 are hereby incorporated by reference. They concern waveguides for the transmission of electromagnetic waves comprising a multitude of structural elements, which are formed non-uniformly but unambiguously according to a predetermined rule. One object of the present invention is to provide a remote sensing device which enables optimization for the respective requirements of various distal light reception / emission or sensor units and in particular allows miniaturization. The invention discloses a remote sensor device comprising a primary light source, an optical waveguide and a light reception / emission unit. The primary light source is designed to emit primary light with a first wavelength. The optical waveguide has a proximal end and a distal end and is designed to transmit the primary light from the proximal end to the distal end and to transmit secondary light with a second wavelength, generated at the distal end by the primary light, back to the proximal end. At the distal end of the optical fiber is the light reception / emission unit for receiving the primary light, especially from the distal end, and for emitting the secondary light to the distal end of the optical fiber. At the proximal end of the optical fiber, a secondary light receiver is preferably located for receiving the secondary light transmitted back from the proximal end of the optical fiber. The secondary light receiver is, in particular, a detector for the secondary light and can, for example, be designed as a photodiode or as an imaging area detector. In particular, it is provided that the optical waveguide has a numerical aperture which is greater than 0.4 or preferably greater than 0.5 or greater than 0.6. This allows for a relatively high light collection efficiency with sometimes small dimensions, which enables optimization of the requirements for the light absorption / emission or sensor unit for various applications. Within the scope of this disclosure, the numerical aperture (NA) of the optical waveguide denotes the sine of the acceptance angle α of the optical waveguide, i.e., the sine of half the opening angle of the optical waveguide. This corresponds to the formula NA = n sin α for n=1. The statement that the optical waveguide has, in particular, a numerical aperture greater than 0.4, or preferably greater than 0.5 or greater than 0.6, is thus equivalent to stating that the optical waveguide has an acceptance angle α greater than 23.6°, or preferably greater than 30.0° or greater than 36.9°. In the case that the optical waveguide comprises at least one optical fiber with a core and a cladding, in particular a step-index fiber, the numerical aperture can also be specified, for example, as where ncore denotes the refractive index of the core and ncladding denotes the refractive index of the cladding. As described, the primary light comprises at least one first wavelength, and the secondary light at least one second wavelength. The second wavelength is, in particular, a wavelength different from the first. However, with regard to specific embodiments, it should not be excluded that the first and second wavelengths are identical. The primary light, as well as the secondary light, can of course also be configured as a spectrum. The light reception / emission unit is configured, in particular, as a sensor unit and / or interaction unit, wherein the light reception / emission unit emits the secondary light after or during the illumination by the primary light and, in this context, enables the determination of a measured quantity. However, it should not be excluded that an interaction of the primary light also occurs outside the light reception / emission unit, for example, in a tissue under investigation. In this respect, the light reception / emission unit can, in one embodiment, also be configured to receive secondary light generated outside the device and, in turn, emit this to the distal end of the optical waveguide, or, if necessary, to emit it to the distal end of the optical waveguide as tertiary light after a further process. According to one embodiment, the optical waveguide can be designed as a so-called Anderson waveguide or TAL waveguide, wherein the optical waveguide is configured to transmit the primary light and / or the secondary light transversally with spatial resolution, and wherein the optical waveguide can also be designed as an image guide. Transverse localization offers the particular advantage of requiring less excitation light or primary light, potentially resulting in a lower background of scattered light, and / or minimizing unused excitation light or primary light that might otherwise be emitted into the sample space. This allows for excitation with primary light in a potentially small area, while simultaneously enabling the absorption of secondary light over a larger cross-section. The optical waveguide comprises a multitude of structural elements, each extending from the proximal to the distal end and partially across the cross-section of the optical waveguide, such that a multitude of cross-sectional regions are defined in the cross-section of the waveguide, each corresponding to the cross-section of a single structural element. Structural elements, especially their cross-sectional regions, are arranged unevenly, such that a transverse Anderson localization of the primary and secondary light is achieved. According to one embodiment, the light-receiving / emitting unit at the distal end of the optical waveguide comprises a material that, after receiving the primary light, enables the emission of secondary light. For example, the material can enable coherent processes such as frequency doubling. In particular, the light reception / emission unit at the distal end of the optical waveguide comprises an excitable material which has an electronic structure that enables excitation by the primary light and decay with emission of the secondary light. Excitation can preferably be achieved by primary light with a wavelength between 200 nm and 20 µm. Alternatively or additionally, decay can preferably be achieved by emitting secondary light with a wavelength between 200 nm and 20 µm. The energy states are preferably configured such that an external measurement quantity can be measured using the received secondary light, for example an external measurement quantity from the group comprising a magnetic field, a conductivity, a temperature, a quantity of substance or substance concentration, e.g. an oxygen saturation. According to one embodiment, the light-receiving / emitting unit at the distal end of the optical waveguide comprises a diamond with one or more nitrogen-vacancy centers as the excitable material, which has an electronic structure that enables excitation by the primary light and decay with emission of the secondary light. Excitation can preferably be achieved by primary light with a wavelength between 500 nm and 560 nm, e.g., 532 nm. Alternatively or additionally, decay can preferably be achieved by emitting secondary light with a wavelength between 600 nm and 800 nm. The energy states are preferably configured such that an external magnetic field can be measured using the received secondary light, in particular by means of a splitting and / or energy shift of spectral lines under the influence of the external magnetic field, preferably under microwave irradiation. The light-absorbing / emitting unit, in particular the diamond, can also include other centers, especially as excitable material, e.g., one or more elements of the carbon-silicon group (of the fourth main group). For example, the light-absorbing / emitting unit, in particular the diamond, can include one or more of the following elements: Si, Ge, Sn, Pb. Excitation can be achieved, particularly in the case of Si, preferably also by primary light with a wavelength between 708 nm and 768 nm. Excitation can be achieved, particularly in the case of Ge, preferably also by primary light with a wavelength between 572 nm and 632 nm. Excitation can be achieved, particularly in the case of Sn, preferably also by primary light with a wavelength between 590 nm and 650 nm. Excitation can be achieved, particularly in the case of Pb, preferably also by primary light with a wavelength between 490 nm and 550 nm and / or between 522 nm and 582 nm. Preferably, the optical waveguide exhibits low intrinsic fluorescence at the wavelength of the primary light and / or the secondary light. In further training, stimulation with primary light encompassing more than one wavelength, in particular encompassing a spectrum, may also be provided. The optical waveguide preferably has a high mean refractive index in order to increase the total reflection angle at the transition to the light reception / emission unit, in particular the diamond (n=2.4). In a further development of the invention, a spatially limited recording of the primary light can be provided, particularly if the primary light is transmitted transversely in a localized manner. This can, for example, enable gradient field measurement. In particular, the light reception / emission unit, the nitrogen vacancy center(s) and / or the excitable material can be arranged at the distal end of the optical waveguide in such a way that spatially limited reception of the primary light, in particular spatially limited excitation by the primary light, is enabled when transversely localized transmission of primary light through the optical waveguide takes place. It may also be provided that the light-receiving / emitting unit, in particular the diamond, has a reflector for deflecting the primary light and / or the secondary light, e.g., a chamfer and / or a coating, in particular such that spatially limited reception of the primary light perpendicular to the cross-sectional area of ​​the distal end of the optical waveguide is enabled. Furthermore, the reflector can serve to deflect the portion of the secondary light that is not emitted towards the distal end. Further training may also include more complex optical designs of the interaction zone, e.g. lenses, a microlens array and / or parabolic mirrors. The light-receiving / emitting unit, in particular the diamond, can be mechanically connected to the distal end of the optical waveguide. In other words, the light-receiving / emitting unit, in particular the diamond, can be firmly attached to the distal end of the optical waveguide. The light reception / emission unit, in particular the diamond, preferably extends over at least 50% of the cross-section of the distal end of the optical waveguide, and particularly preferably over at least 75% of the cross-section of the distal end of the optical waveguide. The nitrogen vacancy centers or the excitable material are preferably arranged only in a spatial sub-region of the light absorption / emission unit or the diamond, for example in a radially inner sub-region which is surrounded by a radially outer sub-region without excitable material or without nitrogen vacancy centers. Preferably, a reflector for deflecting the primary light and / or the secondary light is provided in the radially outer part of the light-receiving / emitting unit or the diamond, e.g. a chamfer and / or a coating. The reflector can preferably deflect secondary light, in particular radially emitted secondary light, to the distal end of the optical waveguide to increase the light-collecting efficiency of the optical waveguide. Alternatively or additionally, the reflector can also deflect primary light, in particular transversely localized primary light, to the nitrogen vacancy centers or the excitable material. The light absorption / emission unit, in particular the diamond, the nitrogen vacancy centers and / or the excitable material, can be arranged at the distal end of the optical waveguide in such a way that at least 0.5%, preferably at least 5% of the secondary light can be coupled into the optical waveguide at the distal end, in particular after deflection by the chamfer or the reflector. The light reception / emission unit, in particular the nitrogen vacancy center(s) and / or the excitable material, may be arranged only over a partial area of ​​the cross-section of the distal end of the optical waveguide, preferably over a partial area of ​​less than 50% of the cross-sectional area, particularly preferably over a partial area of ​​less than 25% of the cross-sectional area. The optical waveguide can have a cross-section between 30µm and 5000µm, preferably between 50µm and 3000µm. The optical waveguide can have a length between 10mm and 10000mm, preferably between 50mm and 2000mm. The optical waveguide can be at least partially flexible and / or at least partially rigid or semi-rigid. In a further development of the invention, a tapered optical waveguide can also be provided. Furthermore, in a further development of the optical waveguide, a cross-section may be smaller than the cross-section of the excitable material, in particular to prevent primary light from passing over the excitable material and entering the light reception / emission unit. Preferably, the optical waveguide has a transmission of at least 30%, preferably at least 40%, and more preferably at least 50%, for a wavelength of 532nm. Furthermore, the optical waveguide preferably has a transmission of at least 30%, preferably at least 40%, and more preferably at least 50%, for a wavelength in the range between 600nm and 800nm. The optical waveguide can exhibit an attenuation of less than 50 dB / m, in particular less than 10 dB / m, and in particular less than 1 dB / m, for a wavelength of 532nm and / or for a wavelength in the range between 600nm and 800nm. Preferably, the optical waveguide is designed to preserve polarization. The optical waveguide can be non-magnetic. The optical waveguide can comprise at least two different types of structural elements, namely a first type with a first refractive index and a second type with a second refractive index. Preferably, the difference in the refractive indices is greater than 0.05, in particular greater than 0.1, in particular greater than 0.2, in particular greater than 0.5. The structure can comprise a plurality of structural elements of the first type and a plurality of structural elements of the second type, wherein the structural elements of the first type are designed as, in particular, rod-shaped or tubular bodies with or made of a first medium, wherein the first medium has the first refractive index, wherein the structural elements of the second type are designed as, in particular, rod-shaped or tubular bodies with or made of a second medium, wherein the second medium has the second refractive index, or wherein the structural elements of the second type are designed as cavities in the structural elements of the first type, wherein the cavities preferably form the second refractive index. It can also comprise a structural element of the first type and a plurality of structural elements of the second type, wherein the structural element of the first type is designed as a, in particular monolithic, base body with or made of a first medium, wherein the first medium has the first refractive index, and wherein the structural elements of the second type are designed as cavities in the base body, wherein the cavities preferably form the second refractive index. As previously described, the structural elements, particularly their cross-sectional regions, are arranged non-uniformly to achieve transverse Anderson localization of the primary and secondary light. The structural elements can, for example, be arranged truly randomly. Alternatively, the non-uniformity can be determined by a predetermined rule. For example, the structural elements, in particular their cross-sectional regions, can have a non-uniform arrangement, which is uniquely defined by a predetermined rule, wherein the non-uniform arrangement, which is uniquely defined by the predetermined rule, is designed (a) as a periodic positioning of structural elements, in particular their cross-sectional regions, wherein the periodically positioned structural elements exhibit a variation among themselves, which is non-uniform but uniquely defined by a predetermined rule, wherein the variation of the periodically positioned structural elements among themselves is preferably designed as a variation of the type of structural elements, the refractive index of the structural elements and / or the geometry (e.g. the shape, the diameter and / or the substructure) of the structural elements, (b) as an aperiodic positioning of structural elements, in particular their cross-sectional regions,wherein the aperiodic positions of the structural elements are formed unevenly but unambiguously by a predetermined rule, wherein optionally the structural elements also exhibit a variation among themselves which is formed unevenly but unambiguously by a predetermined rule, and / or (c) as a positioning of structural elements, in particular their cross-sectional regions, on periodic sites, wherein some of the periodic sites are occupied and some of the periodic sites are unoccupied and the occupancy is formed unambiguously by a predetermined rule, wherein optionally the structural elements also exhibit a variation among themselves which is formed unevenly but unambiguously by a predetermined rule. In one embodiment of the invention, the remote sensing device comprises a microwave generator and / or a microwave antenna for irradiating microwaves onto the light-receiving / emitting unit, in particular the diamond, the nitrogen-vacancy center(s) and / or the excitable material. The remote sensor device preferably comprises an evaluation unit for evaluating the secondary light received by the secondary light receiver in order to determine the external measured quantity using the received secondary light. The invention further relates to a remote sensor unit comprising an optical fiber and a light reception / emission unit. The optical waveguide has a proximal end and a distal end and is designed to transmit primary light from the proximal end to the distal end and to transmit secondary light, preferably of a different wavelength, caused at the distal end by the primary light back to the proximal end. At the distal end of the optical fiber is the light reception / emission unit for receiving the primary light, especially from the distal end, and for emitting the secondary light to the distal end of the optical fiber. In particular, it is provided that the optical waveguide has a numerical aperture which is greater than 0.4 or preferably greater than 0.5 or greater than 0.6. The remote sensing unit may also include one or more of the features described above in connection with the remote sensing device. The remote sensing unit and / or the remote sensing device may include an additional feeder waveguide designed to direct the primary light to the distal end of the optical waveguide. Furthermore, the invention relates to an endoscope comprising a remote sensing device or a remote sensing unit as described above. Preferred embodiments of the invention are described below with reference to the figures. Figure 1 shows a schematic representation of the distal end of an optical waveguide with a light-receiving / emitting unit mounted on the distal end, which receives primary light in the axial direction. Figure 2 shows a schematic representation of the distal end of an optical waveguide with a light-receiving / emitting unit mechanically mounted on the distal end, which receives primary light in the radial direction. Figure 3 shows a schematic illustration of various possibilities for optical waveguides with structural elements or their cross-sectional regions that are unevenly but unambiguously defined by a predetermined rule. Figure 4 shows a schematic illustration of various aspects for variations among structural elements or their cross-sectional regions and possibilities for combinations of these aspects.Fig. 5: Schematic illustration of exemplary possibilities for optical waveguides with structural elements or their cross-sectional regions that are unevenly but unambiguously defined by a predetermined rule, wherein the waveguides each comprise one structural element of a first type and a plurality of structural elements of a second type and, if applicable, further types. Fig. 6: Schematic illustration of various possibilities for waveguides with structural elements or their cross-sectional regions that are unevenly but unambiguously defined by a predetermined rule, wherein the waveguides each comprise a plurality of structural elements of a first type and a plurality of structural elements of a second type and, if applicable, further types. Fig. 7: Schematic perspective views of an optical waveguide with two types of structural elements whose cross-sectional areas are unevenly distributed on a grid.8 : a schematic representation of the distal end of an optical waveguide with a light receiving / emitting unit with excitable material applied to the distal end, which extends transversely over the entire width of the optical waveguide. Fig. 1 shows the distal end of an optical waveguide 1 on which a light-receiving / emitting unit 2 is mechanically mounted. The light-receiving / emitting unit 2 comprises excitable material 20, which, during operation, receives the primary light 3 transmitted through the optical waveguide 1 and emits the secondary light 4. In the example shown, the light-absorbing / emitting unit 2 is configured as a diamond, and the excitable material 20 is configured as a subregion of the diamond in which one or more nitrogen-vacancy centers (NV centers) are located. An NV center is characterized by the fact that one carbon atom in the diamond lattice is replaced by a nitrogen atom (N), and another adjacent carbon atom is missing (V). The excitation is achieved by primary light 3 with a wavelength of, for example, 532 nm or a wavelength between 515 nm and 550 nm. The secondary light 4 can have a wavelength between 600 nm and 800 nm. The optical waveguide 1 is therefore preferably selected such that for a wavelength of 532 nm and for a wavelength in the range between 600 nm and 800 nm, there is a transmission of at least 50%, preferably at least 70%, over the length of the optical waveguide 1. In this embodiment, the NV centers, or the excitable material 20, are arranged in a locally confined area within the light-receiving / emitting unit 2. In this example, the excitable material 20 is arranged transversely over a width B that is less than the width of the optical waveguide 1, in particular less than 40% or less than 30% of it. The excitable material 20 is thus only present transversely in a locally confined area within the light-receiving / emitting unit 2, here the diamond. Since the optical waveguide 1 in this embodiment is designed as an Anderson waveguide, the primary light 3 can be transmitted transversely in a localized manner. This makes it possible to excite the excitable material 20, which is arranged only locally transversely, with transversely localized primary light 3, wherein the transverse position of the primary light 3 corresponds to that of the excitable material 3. The reception of the primary light 3 by the excitable material occurs in the axial direction. The excitable material 20 emits the secondary light 4 in various directions, including radially. Due to the relatively high numerical aperture of the optical waveguide 1, which in this case is greater than 0.5, a high light-collecting efficiency with respect to the secondary light 4 can be achieved. To further increase the light-collecting efficiency, the light-absorbing / emitting unit 2, here the diamond, is provided with a reflective coating 22 applied to its outer surface. Furthermore, the light-absorbing / emitting unit 2, here the diamond, has a circumferential chamfer 24 for deflecting the secondary light, which can also be provided with the coating 22. Fig. 2 shows the distal end of an optical waveguide 1 as in Fig. 1, where the transverse position of the primary light 3 differs from that of the transversely localized excitable material 20. In particular, the transverse position of the primary light 3 can lie in the region of the reflector or the circumferential chamfer 24 of the light-receiving / emitting unit 2. The excitable material 20 is thus spatially limited in its axial excitability (i.e., perpendicular to the cross-sectional area of ​​the distal end of the optical waveguide). It is therefore possible that the excitable material 20, which extends over the height H, is only excited over a portion of this height H, thus enabling gradient field measurement. Referring to Figures 3, 4, 5 to 6, various forms of possible non-uniformity in the structural elements of the optical waveguide will be discussed below by way of example. As described, the structural elements, in particular their cross-sectional regions, can be characterized on the one hand by non-uniformity relative to each other, and on the other hand by regularity such that the non-uniformity of the structural elements is clearly predetermined, in particular deterministic and / or reproducible, and does not follow chance. For example, the structural elements or their cross-sectional regions may have a non-uniform arrangement, which is clearly defined by a predetermined rule, have geometries that are not uniform to each other, which are clearly defined by a predetermined rule, and / or have refractive indices that are not uniform to each other, which are clearly defined by the predetermined rule. Fig. 3 shows, using a tree diagram, various possibilities for realizing a non-uniform arrangement, which is uniquely defined by a predetermined rule. In Fig. 3a, a structural element 10a is shown as the starting point, which can, for example, be designed as a matrix material (it is also possible that the structural element 10a is designed as air or is absent). Fig. 3b shows a further starting point derived from this with the structural element 10a and a plurality of periodic positions P for being filled with structural elements, which then exhibit a periodic positioning. Fig. 3d shows a further starting point derived from Fig. 3a with the structural element 10a and a plurality of aperiodic positions P for being filled with structural elements in order to achieve an aperiodic positioning. Starting from the ones in Fig. 3b and Fig.The waveguides according to the invention are obtained from the starting points shown in 3d by placing structural elements at positions P, as described in more detail below. Starting from Fig. 3b, Fig. 3c shows a waveguide 1 with structural elements 10b, 10c whose cross-sectional regions have a periodic positioning and / or lie at periodic positions. The waveguide shown in Fig. 3c has three types of structural elements 10a, 10b, 10c, each of which can have a different refractive index. For example, the structural element 10a can be designed as a matrix material, and the structural elements 10b and 10c can be cavities in the matrix material filled with materials of different refractive indices. However, it is also possible that one of the materials of structural elements 10b and 10c corresponds to the matrix material of structural element 10a, or that the (filled) cavities corresponding to these structural elements are missing in the matrix material (see Fig. 5a below). It is also possible that structural element 10a is formed as air or is absent, and that structural elements 10b and 10c are adjacent to each other (see Fig. 6a below). The waveguide 1 shown in Fig. 3c has structural elements 10b, 10c with a periodic positioning. However, the structural elements 10b, 10c are of different types, and the distribution of the different types on the regular grid is non-uniform but determined by a predetermined rule. In particular, the variation of the structural elements 10b, 10c among themselves is thus non-uniform but determined by a predetermined rule. The structural elements 10b, 10c can be described as deterministically disordered. Fig. 3c thus shows a case of a waveguide 1 in which the structural elements or their cross-sectional regions have a non-uniform arrangement, which is uniquely determined by a predetermined rule. The term "arrangement" here is to be understood as meaning that the selection orThe allocation of the different types of structural elements 10b, 10c to the respective periodic positions is uneven, but is determined by the predetermined rule, and is therefore not random. It is also possible that the structural elements 10b and 10c do not differ with respect to their refractive indices, i.e., they have the same refractive index or are made of the same material, but vary with respect to other aspects (see Fig. 4 below). It is further possible that the structural elements 10b and 10c differ both with respect to their refractive indices and with respect to other aspects. Starting from Fig. 3d, Fig. 3e shows a waveguide 1 with two types of structural elements: structural element 10a, which can be configured, for example, as a matrix material, and a plurality of structural elements 10b, which can be configured, for example, as cavities, particularly filled ones, within the matrix material. In this case, the cross-sectional regions of the structural elements 10b are positioned aperiodically. The positioning of the structural elements 10b can represent the non-uniformity, which is defined by a predetermined rule. In particular, the structural elements 10b of the second type can have non-uniform positions, but these positions are defined by a predetermined rule. Fig. 3e thus shows a case of a waveguide 1 in which the structural elements, or rather their cross-sectional regions, have a non-uniform arrangement, which is uniquely defined by a predetermined rule.The term "arrangement" here refers to the fact that one or more of the structural elements, or their cross-sectional regions, are positioned aperiodically, with the positions being determined by a predetermined rule and therefore not random. In the case of Fig. 3e, it is specifically provided that the structural elements 10b of the second type have a uniform refractive index, uniform geometries, and / or are uniformly designed with regard to other aspects, in particular, identically designed. In this case, one can speak of a uniform allocation of the aperiodic positions. In contrast, Fig. 3f shows, starting from Fig. 3d, a waveguide 1 in which an aperiodic positioning of structural elements with simultaneously different types of structural elements 10b, 10c is provided. In this case, the non-uniformity, which is uniquely defined by a predetermined rule, can lie in the aperiodic positioning of the structural elements 10b, 10c, or in the arrangement, i.e., the variation of the structural elements 10b, 10c among themselves, or in both the positioning and the arrangement. Fig. 4 shows various possible variations that structural elements can exhibit (middle row) as well as exemplary, non-exhaustive, combinations of these variations (bottom row). The variations shown can be used, in particular, for the allocation of structural elements to positions that are unevenly distributed but clearly defined by a predetermined rule. Structural elements whose cross-sectional regions are located at periodic or aperiodic positions, e.g., within a matrix material, can, for example, vary in shape, type, refractive index, substructure, and / or rotation (and / or local position). For example, variations in the geometries of structural elements, particularly their cross-sectional regions, can manifest as variations in shape (number of vertices, diameter). Variations in geometry can also manifest as variations in the substructure. A substructure can, in particular, consist of a structural element, especially its cross-sectional region, having at least two distinct areas with different refractive indices, specifically a core and a surrounding mantle (core-mantle system). In combination, for example, a first type of structural element can have a polygonal shell and / or a polygonal core, and a second type of structural element can have a circular shell and a polygonal core (bottom row, first column). These two types of structural elements can then be used, for example, to fill periodic or aperiodic positions. Furthermore, for example, a first type of structural element may have a first refractive index and a first diameter, and a second type of structural element may have a second refractive index and a second diameter (bottom row, second column); or a first type of structural element may be a core-cladding system with a core having a first diameter, and a second type of structural element may be a core-cladding system with a core having a second diameter (bottom row, third column); or a first type of structural element may be a core-cladding system with a core having a first refractive index, and a second type of structural element may be a core-cladding system with a core having a second refractive index (bottom row, fourth column);or a first type of structural element having a first diameter and a rotation about a pivot point outside the structural element, and a second type of structural element having a second diameter and a rotation about a pivot point outside the structural element (bottom row, fifth column), or a first type of structural element a core-mantle system with a centered core, and a second type of structural element a core-mantle system with a core having a rotation about a pivot point outside the core (bottom row, sixth column), and the like. Fig. 5a shows a waveguide 1, which is comparable in some aspects to the waveguide from Fig. 3c. The waveguide has a first structural element 10a, which can, for example, be configured as a matrix material. Furthermore, the waveguide has a plurality of structural elements 10b, which can, for example, be configured as filamentous cavities in the matrix material. The structural elements 10b are located at periodic sites, but not all periodic sites are occupied by a structural element. Fig. 5a thus shows a case of a waveguide 1 in which the structural elements or their cross-sectional regions have a non-uniform arrangement, which is uniquely defined by a predetermined rule. The term "arrangement" here is to be understood as meaning that the structural elements or some of the structural elements are arranged in a non-uniform pattern.whose cross-sectional regions lie on periodic sites, some of which are occupied and some of which are unoccupied, and the occupancy is clearly defined by a predetermined rule, i.e., it is not random. Fig. 5b shows a waveguide 1, which is comparable in some aspects to the waveguide in Fig. 3f. The waveguide has a first structural element 10a, which can, for example, be designed as a matrix material. Furthermore, the waveguide has a plurality of structural elements 10b with a first diameter and a plurality of structural elements 10c with a second diameter. In this example, the structural elements are positioned aperiodically, whereby the aperiodic positioning can be non-uniform but is clearly defined by a predetermined rule. Fig. 5b thus shows a case of a waveguide 1 in which the structural elements or their cross-sectional regions have a non-uniform arrangement, which is clearly defined by a predetermined rule. The term "arrangement" here is to be understood as meaning that the structural elements or some of them are arranged in a specific way.whose cross-sectional regions are positioned aperiodically, wherein the aperiodic positions are determined by the predetermined rule, i.e., are not random, and / or wherein the structural elements exhibit a variation among themselves, which is uneven but clearly defined by a predetermined rule, wherein the variation is formed as two types of structural elements, e.g., with different diameters. Fig. 6 shows several waveguides 1, each with a plurality of structural elements of a first type and a plurality of structural elements of a second type (and sometimes further types in Fig. 6d). The waveguides 1 shown here do not have a matrix material; rather, the structural elements are adjacent to one another. The waveguides 1 shown in Fig. 6 have in common that the structural elements of the different types, especially their cross-sectional regions, are positioned periodically. However, the allocation of the types of structural elements to the periodic positions is uneven but clearly defined by a predetermined rule. The waveguides 1 shown in Fig. 6 are thus characterized by the fact that the structural elements, or rather,whose cross-sectional regions exhibit a non-uniform arrangement, which is clearly defined by a predetermined rule, whereby the term arrangement is to be understood in such a way that the selection or allocation of the different types of structural elements on the periodic positions is non-uniform, but is defined by the predetermined rule, i.e., it is not random. Fig. 6a shows approximately a waveguide 1 with a plurality of structural elements 10a and a plurality of structural elements 10b, which have different refractive indices. Fig. 6b shows a waveguide 1 with a plurality of structural elements 10d and a plurality of structural elements 10e, which have different refractive indices and a different substructure, wherein the substructure is defined by the sub-structural elements 10a and 10b (with refractive indices a and b) and 10a and 10c (with refractive indices a and c), respectively. The substructure here consists in the fact that the structural elements 10d and 10e are configured as core-cladding systems, the cores of which differ. Fig. 6c similarly shows a waveguide 1 with a plurality of structural elements 10d and a plurality of structural elements 10e, which have different refractive indices and a different substructure, wherein the substructure is defined by the sub-structural elements 10a and 10b (with refractive indices a and b) and 10c and 10b (with refractive indices c and b), respectively. The substructure here consists in the fact that the structural elements 10d and 10e are configured as core-cladding systems, with the claddings differing. Fig. 6d similarly shows a waveguide 1 with a plurality of structural elements 10e, 10f, 10g, and 10h, which have different refractive indices and different substructures, the substructure being defined by the sub-structural elements 10a and 10b (with refractive indices a and b), 10a and 10c (with refractive indices a and c), 10b and 10d (with refractive indices b and d), and 10c and 10d (with refractive indices c and d). The substructure here consists in the fact that the structural elements 10e, 10f, 10g, and 10h are configured as core-cladding systems, with both the cladding and the cores differing. Fig. 6e shows a waveguide 1 with a plurality of structural elements 10c and a plurality of structural elements 10d, which have different geometries and a different substructure, wherein the substructure of the structural element 10c is defined by the sub-structural elements 10a and 10b (with refractive indices a and b and a first core diameter), and the substructure of the structural element 10d is defined by the sub-structural elements 10a and 10b (with refractive indices a and b and a second core diameter). Fig. 6f shows a waveguide 1 with a plurality of structural elements 10c and a plurality of structural elements 10d, which have different geometries and a different substructure, wherein the substructure of the structural element 10c is defined by the sub-structural elements 10a and 10b (with refractive indices a and b and a centrally positioned core), and the substructure of the structural element 10d is defined by the sub-structural elements 10a and 10b (with refractive indices a and b and an eccentrically positioned core). Fig. 7 shows an example of a three-dimensional view of an optical waveguide 1 with a plurality of structural elements of a first type 10a and a plurality of structural elements of a second type 10b. In this example, the cross-sectional regions of the structural elements are arranged on a periodic grid. Fig. 8 shows another embodiment of a remote sensing unit with an optical waveguide 1 and a light-receiving / emitting unit 2 applied to the distal end of the optical waveguide 1. In this example, the light-receiving / emitting unit 2 comprises excitable material 20, which extends radially over substantially the entire width of the optical waveguide. Alternatively, the excitable material can extend over a width that corresponds to at least 50 percent, preferably at least 75 percent, of the width of the light-receiving / emitting unit 2 and / or the optical waveguide 1. In some embodiments, the excitable material extends axially (i.e.,perpendicular to the cross-sectional area of ​​the distal end of the optical waveguide) only over a portion of the light reception / emission unit 2, for example over less than 90 percent, in particular over less than 75 percent of the height of the light reception / emission unit 2. Preferably, however, the excitable material extends in the axial direction over the entire light reception / emission unit 2. Specifically, the light absorption / emission unit 2 can, for example, be designed as a diamond layer extending over the entire distal facet. The excitable material can, for example, be designed as a homogeneous, at least radially, distribution of NV centers. In the described embodiment, the light-receiving / emitting unit 2 and / or the excitable material 20 can be irradiated with primary light 3 across their entire surface. The secondary light 4 emitted by the light-receiving / emitting unit 2 to the distal end of the optical waveguide 1 can have varying intensities in the radial direction, i.e., along the width of the excitable material 20. This secondary light 4 is then transmitted transversely through the optical waveguide 1, which is designed as an Anderson waveguide. The described embodiment thus enables the realization of a remote sensor unit which forms a radially spatially resolved sensor, e.g. a 2D sensor.

Claims

Remote sensing device comprising: a primary light source for emitting primary light (3) with a first wavelength, an optical waveguide (1) with a proximal end and a distal end, configured for transmitting the primary light (3) from the proximal end to the distal end and for transmitting secondary light (4) with a second wavelength caused at the distal end by the primary light (3) back to the proximal end, a light receiving / emitting unit (2) arranged at the distal end of the optical waveguide (1) for receiving the primary light (3) from the distal end and for emitting the secondary light (4) to the distal end of the optical waveguide (1), and a secondary light receiver arranged at the proximal end of the optical waveguide (1) for receiving the secondary light (4) from the proximal end of the optical waveguide (1), wherein the optical waveguide (1) has a numerical aperture greater than 0.5.wherein the optical waveguide (1) comprises a plurality of structural elements (10), each extending from the proximal to the distal end and partially across the cross-section of the optical waveguide, such that a plurality of cross-sectional regions are defined in the cross-section of the waveguide, each corresponding to the cross-section of a single structural element (10), and wherein the structural elements (10), in particular their cross-sectional regions, are arranged non-uniformly to effect a transverse Anderson localization of the primary light and the secondary light. Remote sensor device according to the preceding claim, wherein the optical waveguide (1) is configured to transmit the primary light (3) and / or the secondary light (4) transversely localized with a spatial resolution such that the optical waveguide forms an image guide. Remote sensing device according to one of the preceding claims, wherein the light receiving / emitting unit (2) at the distal end of the optical waveguide (1) comprises a material which enables the emission of secondary light after receiving primary light, and / or wherein the light receiving / emitting unit (2) at the distal end of the optical waveguide (1) comprises an excitable material (20) which has an electronic structure which enables excitation by the primary light (3) and decay by emission of secondary light (4), wherein the excitation is preferably enabled by primary light (3) with a wavelength between 200 nm and 20 µm and / or the decay is preferably enabled by emission of secondary light (4) with a wavelength between 200 nm and 20 µm. Remote sensing device according to one of the preceding claims, wherein the light reception / emission unit (2) at the distal end of the optical waveguide (1) comprises a diamond with one or more nitrogen vacancy centers as excitable material, which has an electronic structure that enables excitation by the primary light and decay by emission of the secondary light, wherein the excitation is preferably enabled by primary light (3) with a wavelength between 500 nm and 560 nm, e.g. 532 nm and / or the decay is preferably enabled by emission of secondary light (4) with a wavelength between 600 nm and 800 nm. Remote sensing device according to one of the preceding claims, wherein the light reception / emission unit (2), in particular the nitrogen vacancy centers and / or the excitable material (20), is arranged at the distal end of the optical waveguide such that spatially limited reception of the primary light, in particular spatially limited excitation by the primary light, is enabled when transversely localized transmission of primary light through the optical waveguide takes place, and / or wherein the light reception / emission unit (2), in particular the diamond, has a reflector for deflecting the primary light and / or the secondary light. Remote sensing device according to any one of claims 3 to 5, wherein the light receiving / emitting unit (2), in particular the diamond, is mechanically connected to the distal end of the optical waveguide (1), and wherein the light receiving / emitting unit (2), in particular the diamond, preferably extends over at least 50% of the cross-section of the distal end of the optical waveguide, and wherein the nitrogen vacancy centers or the excitable material (20) are preferably arranged only in a spatial subregion of the light receiving / emitting unit or the diamond, wherein at least in the radially outer subregion of the light receiving / emitting unit or the diamond a reflector for deflecting the primary light and / or the secondary light is preferably provided, and wherein the reflector preferably deflects secondary light (4), in particular radially emitted secondary light, to the distal end of the optical waveguide.to increase the light-collecting efficiency of the optical waveguide, and / or wherein the reflector deflects primary light (3), in particular transversely localized primary light, onto the nitrogen vacancy centers or the excitable material. Remote sensing device according to one of claims 3 to 6, wherein the nitrogen vacancy centers or the excitable material (20) extend radially substantially over the entire width of the light reception / emission unit, in particular the diamond, or extend over at least 50% of the cross-section of the light reception / emission unit, in particular the diamond, and / or wherein the nitrogen vacancy centers or the excitable material (20) extend radially substantially over the entire width of the optical waveguide or extend over at least 50% of the cross-section of the optical waveguide. Remote sensing device according to one of the preceding claims, wherein the light receiving / emitting unit (2), in particular the diamond, the nitrogen vacancy center(s) and / or the excitable material (20), is arranged at the distal end of the optical waveguide such that at least 0.5% of the secondary light (4) can be coupled into the optical waveguide (1) at the distal end, and / or wherein the light receiving / emitting unit (2), in particular the nitrogen vacancy center(s) and / or the excitable material (20), is arranged only over a partial region of the cross-section of the distal end of the optical waveguide, preferably over a partial region of less than 50% of the cross-sectional area. Remote sensor device according to one of the preceding claims, wherein the optical waveguide (1) has a cross-section between 30µm and 5000µm, and / or wherein the optical waveguide (1) has a length between 10mm and 10000mm, and / or wherein the optical waveguide (1) is at least partially flexible and / or at least partially rigid. Remote sensor device according to one of the preceding claims, wherein the optical waveguide (1) has a transmission of at least 30% for a wavelength of 532 nm and / or wherein the optical waveguide (1) has a transmission of at least 30% for a wavelength in the range between 600 nm and 800 nm and / or wherein the optical waveguide (1) has an attenuation of less than 50 dB / m for a wavelength of 532 nm and / or for a wavelength in the range between 600 nm and 800 nm, and / or wherein the optical waveguide (1) is polarization-preserving and / or wherein the optical waveguide is non-magnetic. Remote sensor device according to one of the preceding claims, wherein the optical waveguide (1) comprises at least two different types of structural elements (10), namely a first type with a first refractive index and a second type with a second refractive index, wherein preferably a plurality of structural elements of the first type and a plurality of structural elements of the second type are comprised, wherein the structural elements of the first type are configured as, in particular rod-shaped or tubular, bodies with or made of a first medium, wherein the first medium has the first refractive index, wherein the structural elements of the second type are configured as, in particular rod-shaped or tubular, bodies with or made of a second medium, wherein the second medium has the second refractive index, or wherein the structural elements of the second type are configured as cavities in the structural elements of the first type.wherein the cavities preferably form the second refractive index, and / or wherein preferably a structural element of the first type and a plurality of structural elements of the second type are comprised, wherein the structural element of the first type is configured as a, in particular monolithic, base body with or made of a first medium, wherein the first medium has the first refractive index, and wherein the structural elements of the second type are configured as cavities in the base body, wherein the cavities preferably form the second refractive index. Remote sensor device according to one of the preceding claims, wherein the structural elements (10), in particular their cross-sectional regions, have a non-uniform arrangement which is uniquely defined by a predetermined rule, wherein the non-uniform arrangement which is uniquely defined by the predetermined rule is designed (a) as a periodic positioning of structural elements, in particular their cross-sectional regions, wherein the periodically positioned structural elements exhibit a variation among themselves which is non-uniform but uniquely defined by a predetermined rule, wherein the variation of the periodically positioned structural elements among themselves is preferably designed as a variation of the type of the structural elements, the refractive index of the structural elements and / or the geometry (e.g. the shape, the diameter and / or the substructure) of the structural elements,(b) as an aperiodic positioning of structural elements, in particular their cross-sectional regions, wherein the aperiodic positions of the structural elements are formed unevenly but unambiguously by a predetermined rule, wherein optionally the structural elements also exhibit a variation among themselves which is formed unevenly but unambiguously by a predetermined rule, and / or (c) as a positioning of structural elements, in particular their cross-sectional regions, on periodic sites, wherein some of the periodic sites are occupied and some of the periodic sites are unoccupied and the occupancy is formed unambiguously by a predetermined rule, wherein optionally the structural elements also exhibit a variation among themselves which is formed unevenly but unambiguously by a predetermined rule. Remote sensor device according to one of the preceding claims, wherein the structural elements (10), in particular their cross-sectional regions, are arranged, preferably in such a non-uniform manner, and particularly preferably in such a non-uniform manner but clearly defined by a predetermined rule, such that the optical waveguide has a numerical aperture which is greater than 0.4, preferably greater than 0.5, and particularly preferably greater than 0.

6. Remote sensor device according to one of the preceding claims, further comprising a microwave generator and / or a microwave antenna for irradiating microwaves onto the light reception / emission unit (2), in particular the diamond, the nitrogen vacancy centers or centers and / or the excitable material (20) and / or further comprising an evaluation unit for evaluating the secondary light (4) received by the secondary light receiver for determining the external measured quantity using the received secondary light. Remote sensing unit comprising: an optical waveguide (1) with a proximal end and a distal end, configured for transmitting primary light (3) from the proximal end to the distal end and for transmitting secondary light (4) of a different wavelength, caused at the distal end by the primary light (3), back to the proximal end, and a light receiving / emitting unit (2) arranged at the distal end of the optical waveguide (1) for receiving the primary light (3), in particular from the distal end, and for emitting the secondary light (4) to the distal end of the optical waveguide (1), wherein the optical waveguide (1) has a numerical aperture greater than 0.5, wherein the optical waveguide (1) comprises a plurality of structural elements (10), each extending from the proximal to the distal end and partially over the cross-section of the optical waveguide, such thatthat a plurality of cross-sectional regions are defined in the cross-section of the waveguide, each corresponding to the cross-section of a single structural element (10), and wherein the structural elements (10), in particular their cross-sectional regions, are arranged non-uniformly to effect a transverse Anderson localization of the primary light and the secondary light. Remote sensor unit according to the preceding claim comprising one or more of the features according to any one of claims 1 to 13. Endoscope comprising a remote sensing device or a remote sensing unit according to any of the preceding claims.

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