Optical-electrical conductor system with adapter sleeve, method for producing an optical-electrical conductor system and device for detecting the immersion of an optical-electrical conductor arrangement in a conductive medium

Abstract

Optical-electrical conductor system (100) comprising: an optical-electrical conductor arrangement (1) comprising an optical waveguide (10) with an outer, organic cladding layer (13), and a conductive layer (22) applied directly or indirectly to the outer cladding layer (13) of the optical waveguide (10) as a coating, consisting of a single layer or a sequence of layers, and an adapter sleeve (30) which is at least partially electrically conductive and which mechanically grips the optical-electrical conductor arrangement (1) and electrically contacts its conductive layer (22), in particular in such a way that the optical-electrical conductor system (100) with the adapter sleeve (30) can be inserted into a connection socket for transmitting optical and / or electrical signals, e.g. arranged on a handpiece, wherein the adapter sleeve (30) has an electrically conductive contacting section (32) which electrically contacts the conductive layer (22) of the optical-electrical conductor arrangement (1), wherein an electrically conductive adhesive (41) is introduced into the contacting section (32) and electrically contacts the conductive layer (22) of the optical-electrical conductor arrangement (1).

Description

[0001] The invention relates to an optical-electrical conductor system with an organically sheathed and conductively coated optical waveguide which can be inserted into a connection socket of a hand-held device.

[0002] Optical fibers are used to transmit light or energy for numerous applications. In some cases, it is desirable to enable the transmission of electrical signals in addition to light transmission, for example, to control the light transmission depending on the electrical signals. This can be achieved by applying a conductive layer to the optical fiber or its sheath.

[0003] German patent application DE 10 2012 109 088 A1, for example, describes a fiber optic conversion module as part of a lighting system in a vehicle, in which optical fibers with an electrically conductive coating can be used, allowing the detection of a fiber break. A fiber break leads to an interruption of an electrical circuit path, which can be detected by a lack of or decreasing current in the detection devices and is used to deactivate excitation light sources.

[0004] German patent application DE 10 2006 029 203 A1 relates to a light-emitting device with a light guide. An electrically conductive connection can be present on the surface of the cladding region of the light guide. This electrically conductive connection winds around the cladding region or is arranged circumferentially around the light guide and can thus detect possible damage or breakage of the light guide at various locations.

[0005] US Patent No. 5,135,295 A describes piezoelectric and ultrasonic devices using optical fibers coated with thin piezoelectric and ferroelectric lead zirconate titanate films. The PZT thin films are chemically prepared using a sol-gel process.

[0006] Regardless of a conductive coating, optical fibers are also generally used in the field of medical technology. WO 2019 / 057316 A1 and US 2019 / 0090998 A1, for example, relate to a method and an arrangement for cleaning a circumferentially closed channel using an optical fiber guiding a laser beam.

[0007] CA 2 841 689 A1 provides an optical connection device comprising a connector connected to an electro-optical composite cable containing an optical fiber and a metal conductor, and a connection object to be connected. The connector is provided with a sleeve having a conductive portion on at least part of its surface.

[0008] DE 10 2011 003 199 A1 discloses an electro-optical probe for endoscopic examinations. The electro-optical probe comprises at least one optical fiber for conducting optical signals. Furthermore, the optical fiber has at least one electrically conductive coating. At least one electrode tip is provided at the end of the optical fiber, which is electrically coupled to the electrically conductive coating.

[0009] US 2010 0 272 398 A1 relates to a device for applying energy to an object and / or for detecting the object. The device comprises an optical device for applying and / or detecting light energy and an electrical device for applying and / or detecting electrical energy. An optical fiber is provided for applying light energy to the object and / or detecting the object, wherein the optical fiber is connected to the optical device, wherein the optical fiber comprises a conductive coating for applying electrical energy to the object and / or for detecting the object, and wherein the electrical conductor is connected to the electrical device.

[0010] US Pat. No. 5,497,442 A relates to an optical fiber for high-power laser transmission, consisting of a glass fiber with a fiber core and a fiber cladding surrounding the fiber core. An intermediate polymer layer is disposed on the fiber cladding, a metallic film coating is disposed on the intermediate layer, and the metallic coating is protected against mechanically induced damage by an outer cladding.

[0011] US 2010 0 057 179 A1 describes thin conductive metal coatings suitable for flexible non-metallic fine wires and leads. Polymer-coated silica fiber cores are manufactured by plasma deposition with two layers of metals such as silver, gold, or titanium to provide micro-thin leads, such as those used in cardiac pacemakers, that are resistant to bending fracture and conductive.

[0012] US 4,609,437 A relates to optical fibers that consist of a synthetic resin at least on their outer periphery and are continuously provided with a metal coating by electroplating. For this purpose, the synthetic resin coating is made electrically conductive, for example, by continuous electroless metallization.

[0013] WO 2017 / 120400 A1 provides various examples and systems for improving optical fibers for sensing temperature and / or strain at low temperatures. An improved optical fiber for distributed sensing may comprise a core, a cladding surrounding the core, and a coating surrounding the cladding.

[0014] JP S55-76 306 A describes that a buffer layer with a thermal expansion coefficient between those of the optical guide and the conductive layer is formed on a quartz glass optical fiber.

[0015] US 2017 / 0 276 869 A1 relates to an optical fiber coated with metallized polymers comprising a thin layer of chromium which is applied to the polymer sheath at low temperature in a vacuum and then electroplated with a thicker layer of copper.

[0016] JP H08-19 557 A relates to an optical root canal treatment device for measuring the length of a root canal and treating it. For this purpose, a root canal electrode is inserted into a root canal, while a mouth electrode is attached to the lower lip. These electrodes are electrically connected to a root canal length measuring device for both healing the root canal through light irradiation and measuring the length of the root canal.

[0017] It would be desirable to be able to attach optical fibers, which are intended for attachment to a handheld device or handpiece, in a simple, modular and interchangeable manner, while at the same time enabling precise arrangement and, in the case of a conductive coating, electrical contact.

[0018] The object of the invention is achieved by the subject matter of the independent claims. Advantageous developments of the invention are defined in the subclaims.

[0019] The invention relates to an optical-electrical conductor system with an optical-electrical conductor arrangement and an adapter sleeve for receiving the optical-electrical conductor arrangement.

[0020] The optical-electrical conductor arrangement comprises an optical waveguide with an outer, organic cladding layer, and a conductive layer applied directly or indirectly to the outer cladding layer of the optical waveguide, consisting of a single layer or a sequence of layers.

[0021] The adapter sleeve is designed to be electrically conductive at least in some areas and serves, on the one hand, to mechanically grasp the optical-electrical conductor arrangement and, on the other hand, to electrically contact its conductive layer, in particular in such a way that the optical-electrical conductor system together with the surrounding adapter sleeve can be inserted into a connection socket for transmitting optical and / or electrical signals, for example arranged on a hand-held device or handpiece.

[0022] In geometric terms, the adapter sleeve preferably has an outer sleeve body enclosing an inner receiving opening. The optical-electrical conductor arrangement can then extend through the inner receiving opening of the adapter sleeve along a sleeve axis defined by the adapter sleeve.

[0023] Preferably, the inner receiving opening of the adapter sleeve is cylindrically shaped, so that an optical-electrical conductor arrangement with a round cross-section can be snugly accommodated therein. Furthermore, the inner receiving opening of the adapter sleeve is preferably arranged concentrically with the outer sleeve body, which may also be cylindrically shaped.

[0024] Preferably, the optical-electrical conductor arrangement is inserted into the adapter sleeve with one (proximal) end, whereby this end can optionally be flush with the adapter sleeve. At least the other (distal) end of the optical-electrical conductor arrangement preferably protrudes from the adapter sleeve. Since light is typically coupled into the optical fiber at the proximal end and exits the optical fiber again at the distal end, the optical-electrical conductor arrangement is preferably held in the adapter sleeve in such a way that at least the optical fiber is accessible from both sides of the adapter sleeve.

[0025] The distal end of the optical-electrical conductor arrangement, which generally serves to couple out light, can be substantially flat. However, it can also be provided that the distal end of the optical-electrical conductor arrangement is modified and / or structured and / or roughened with regard to its substantially flat geometry, in particular at least partially or sectionally, e.g., frustoconically shaped, with an angle of less than 90° to the longitudinal axis of the optical-electrical conductor arrangement, for example, in order to provide a required or aligned radiation of the light coupled in at the proximal end and guided therein in a modified manner. This can be achieved, for example, by sharpening, grinding at least on one side and / or polishing, or by means of physical or chemical etching processes.

[0026] To mechanically grip the optical-electrical conductor arrangement, the adapter sleeve preferably has a fixing section, in particular a dedicated fixing section. An adhesive can be incorporated into this fixing section, which additionally fixes the optical-electrical conductor arrangement. The adhesive has a thickness in the radial direction, in particular between 1 and 500 micrometers, preferably between 5 and 100 micrometers, particularly preferably between 10 and 50 micrometers.

[0027] If the adapter sleeve is inserted into a complementary connection socket, light can be coupled into the optical fiber of the optical-electrical conductor arrangement via the connection socket.

[0028] In order to ensure a precise coupling as centrally as possible into the optical waveguide in this case, it can be provided that the fixing section of the adapter sleeve detects the optical-electrical conductor arrangement with a radial tolerance of less than 50µm, preferably less than 30µm.

[0029] This can be made possible, in particular, by providing the fixing section of the adapter sleeve with a radial clearance of less than 50 µm, preferably less than 30 µm, relative to the optical-electrical conductor arrangement. Even in the case where one or more outer layers of the optical-electrical conductor arrangement are stripped, a clearance of less than 50 µm, preferably less than 30 µm, relative to the respective outermost component of the optical-electrical conductor arrangement can be provided.

[0030] Particularly preferably, the fixing section of the adapter sleeve grips the optical-electrical conductor arrangement in such a way that the optical waveguide of the optical-electrical conductor arrangement is gripped centrally to the sleeve axis with a concentricity error of less than 50µm, preferably less than 30µm.

[0031] Alternatively or in addition to the fixing section described above, the adapter sleeve can have an electrically conductive contacting section, in particular a separate one, but possibly also formed jointly with the fixing section, which electrically contacts the conductive layer of the optical-electrical conductor arrangement. An electrically conductive adhesive can be introduced into this contacting section, which electrically contacts the conductive layer of the optical-electrical conductor arrangement. The conductive adhesive has a thickness in the radial direction, in particular between 1 and 500 micrometers, preferably between 25 and 250 micrometers, particularly preferably between 50 and 150 micrometers.

[0032] It can be provided that the inner receiving opening of the adapter sleeve has a smaller cross-section in the region of the fixing section than in the region of the contacting section. In this case, a transition region from the smaller cross-section to the larger cross-section can be arranged between the fixing section and the contacting section. Such a transition region can be designed, for example, as a cone or an annular shoulder.

[0033] In principle, the invention can be used for optical-electrical conductor arrangements and adapter sleeves of any size. For example, the adapter sleeve may have an outer diameter of less than 20 millimeters, preferably less than 10 millimeters, particularly preferably less than 5 millimeters, and / or an inner diameter of less than 2000 micrometers, preferably less than 1000 micrometers, particularly preferably less than 500 micrometers.

[0034] Since the adapter sleeve is designed to be electrically conductive at least in some areas, it may be advisable for the adapter sleeve to comprise or consist of a metal, e.g. stainless steel or nickel silver, or a conductive plastic or a conductive ceramic.

[0035] A possible application of the presented optical-electrical conductor system is the measurement of an impedance between the adapter sleeve, which in particular electrically contacts the proximal end of the optical-electrical conductor arrangement, and the conductive layer, in particular at the distal end of the optical-electrical conductor arrangement, or a conductive medium surrounding the conductive layer, into which the optical-electrical conductor arrangement can be immersed with its distal end.

[0036] In particular for this purpose, but also independently thereof, it can be provided that an impedance can be measured between the adapter sleeve and the conductive layer of the optical-electrical conductor arrangement, wherein the impedance has, on the one hand, a conductive layer component and, on the other hand, a contacting component.

[0037] The conductive layer component can depend on or be formed by the impedance of the conductive layer and / or the impedance of the conductive layer to a medium surrounding the optical-electrical conductor arrangement. The contacting component, on the other hand, can depend on or be formed by at least the ohmic resistance of the conductive adhesive introduced into the contacting section and / or the capacitive resistance of the conductive adhesive introduced into the contacting section.

[0038] In a preferred embodiment, the contacting component of the impedance is less than or equal to 10 times, preferably less than or equal to 5 times, particularly preferably less than or equal to 0.5 times the conductive layer component of the impedance.

[0039] In particular, the described impedance measurable between the adapter sleeve and the conductive layer of the optical-electrical conductor arrangement is measurable at a specific evaluation frequency or over an evaluation frequency range, wherein the evaluation frequency or the evaluation frequency range is preferably in the range from 1 Hz to 10 GHz, more preferably in the range from 10 Hz to 2.4 GHz, even more preferably in the range from 100 Hz to 1 MHz, particularly preferably in the range from 1 kHz to 100 kHz and most preferably in the range from 1 KHz to 10 kHz.

[0040] Furthermore, the impedance measurable between the adapter sleeve and the conductive layer of the optical-electrical conductor arrangement is preferably measurable between the outer sleeve body of the adapter sleeve and a region of the conductive layer in a section of the optical-electrical conductor arrangement protruding from the adapter sleeve, preferably at the end.

[0041] As described, the contacting component of the impedance can depend at least on the ohmic or capacitive resistance of the conductive adhesive applied in the contacting section. Furthermore, the contacting component can also depend, among other things, on the ohmic resistance of the adhesive applied in the fixing section and / or the capacitive resistance of the adhesive applied in the fixing section.

[0042] If the optical-electrical conductor arrangement includes a barrier layer, this can also contribute to the contacting component of the impedance. A barrier layer can serve to inhibit the diffusion of oxygen and / or ions from acidic or alkaline solutions into the conductive layer and can, for example, be applied directly or indirectly to the conductive layer.

[0043] In the case of such a barrier layer, the contacting portion may further depend on the ohmic resistance of the barrier layer in the region of the adhesive introduced in the fixing section and / or the capacitive resistance of the barrier layer in the region of the adhesive introduced in the fixing section.

[0044] Furthermore, the ohmic resistance of the adapter sleeve can be between 1 and 1000 milliohms, preferably between 10 and 1000 milliohms, particularly preferably between 10 and 100 milliohms. Depending on the type of contact and the design of the adapter sleeve, this can in particular be the ohmic resistance in the radial direction through the outer sleeve body.

[0045] Furthermore, it can be provided that the ohmic resistance of the conductive layer is between 1 and 1000 ohms, preferably between 10 and 500 ohms, particularly preferably between 10 and 100 ohms. This can in particular be the ohmic resistance along the longitudinal extent of the optical-electrical conductor arrangement.

[0046] The above electrical properties of the optical-electrical conductor system can advantageously serve to facilitate the measurement of an impedance or an impedance change when the optical-electrical conductor arrangement is immersed in a medium.

[0047] According to one embodiment, for example, the impedance component of the contacting of the conductive layer, which is formed by capacitive and ohmic resistances of the adhesive and / or the electrically conductive adhesive and optionally a barrier layer at a specific evaluation frequency, can be a maximum of 10 times, preferably a maximum of 5 times, particularly preferably a maximum of 0.5 times the impedance of the conductive layer and / or the impedance of the conductive layer to a conductive medium surrounding the conductor system.

[0048] The evaluation frequency can be in the range of 100 Hz to 1 MHz, preferably in the range of 1 kHz to 100 kHz, and particularly preferably in the range of 1 kHz to 10 kHz. Higher frequencies may be less suitable in some cases, as RF interference may already occur in the RF range. On the other hand, in some cases, frequencies that are too low may result in excessively high impedances at the capacitive transitions.

[0049] The optical-electrical conductor arrangement (accommodated in the adapter sleeve) will be discussed in more detail below.

[0050] As explained above, the optical-electrical conductor arrangement comprises an optical waveguide with an outer, organic cladding layer. A functional layer system can be arranged on the outer cladding layer, which can comprise a base layer region, wherein the electrically conductive layer can be applied to the base layer region. The base layer region can consist of a single layer or a sequence of layers. Likewise, the electrically conductive layer can consist of a single layer or a sequence of layers.

[0051] The optical waveguide, on whose outer cladding layer the conductive layer or optionally a functional layer system is located, can be designed in various ways, as is known to those skilled in the art. Typically, the optical waveguide comprises at least one optically conductive core, preferably made of glass, in particular quartz glass, into which electromagnetic radiation, for example that of a laser, can be coupled. The core can be directly surrounded by a cladding located between the core and the outer cladding layer. Such a cladding can also be made of quartz glass. The inner core has a higher refractive index than the cladding. The core preferably has a diameter of 10 to 600 µm, the cladding typically has a diameter corresponding to 1.1 to 1.5 times the core diameter, and the wall thickness of the cladding layer is preferably in the range of 1 to 100 µm.It can also be provided that the inner core is directly surrounded by the outer cladding layer. In this case, the refractive index of the core is higher than that of the cladding layer.

[0052] In one embodiment, it can also be provided that the functional layer system is located directly on the optically conductive core. In this embodiment, the optical waveguide therefore does not comprise an outer cladding layer. In other words, a pure quartz glass fiber can be provided, for example, with the functional layers applied directly to it and, in particular, can be sealed by a final polymer layer.

[0053] The organic coating layer surrounding the core, which can also be designed as a sizing layer, preferably comprises polyamide (PA), polyimide (PI) or polymethyl methacrylate (PMMA) or wax, wax-like components or alkylsilane or is made of at least one of these materials.

[0054] As explained, a functional layer system located on the cladding layer can comprise a base layer region located beneath the conductive layer. The base layer region can be formed as a layer applied to the outer cladding layer comprising an oxide, in particular SiO2, TiO2, Al2O3, SnO2, HfO2, or a boride, carbide, nitride, oxynitride, carbonitride, or a metal, in particular Si, Ti, Mo, or Cr, or as a sequence of such layers applied to the outer cladding layer. In other words, the outer cladding layer can be coated with a single layer or with multiple layers that form a base layer region. Such a layer or layer sequence can be produced or manufactured, for example, by a coating process, as explained in more detail below. A base layer region can, in particular, be formed as an inorganic adhesion promoter layer based on oxides, such as SiO2, TiO2, Al2O3, SnO2, HfO2, etc., borides, carbides, nitrides, oxynitrides, carbonitrides or metals, such as Si, Ti, Mo or Cr, as a single layer or as a layer sequence of these materials. Preferred layer systems comprise TiO2. In other words, a base layer region preferably contains TiO2 and in particular comprises a plurality of layers, wherein at least one of these layers contains TiO2. These coatings can be applied, among other things, by means of a sputtering process from a so-called sputtering target, wherein these materials can be present as metallic targets or as partially ceramic targets. The purity of the targets is typically specified as 99% or more. Lower purities are also possible, however. In this case, greater layer thicknesses may then be required.

[0055] According to another embodiment, a base layer region may comprise a superficial layer of the outer cladding layer with at least one modified surface property, in particular an increased surface energy and / or an increased number of oxygen radicals. Such a superficial partial layer of the cladding layer may, for example, be produced or manufactured by chemical or physical processes for changing the surface properties of the cladding layer, in particular plasma treatment (e.g., low-pressure plasma or atmospheric plasma), UV treatment, arc discharge (corona), and / or by chemical treatment, e.g., by means of alkaline cleaners in an ultrasonic bath, or a combination of such processes, as described in more detail below.In other words, a base layer region or a lowermost layer of the base layer region can be formed by a radial part of the outer cladding layer comprising the outer surface. A base layer region can therefore, for example, consist of a single layer, wherein this single layer is formed by means of chemical or physical processes based on the outer cladding layer of the optical fiber with regard to the surface properties. A base layer region can, however, also consist of a sequence of layers, wherein, for example, the lowermost layer of a base layer region is formed by chemical or physical processes based on the outer cladding layer of the optical fiber with regard to the surface properties, and further layers are applied to this lowermost layer.

[0056] It can therefore also be provided that a base layer region consists of several layers, wherein a lowest layer is designed as such a surface layer of the outer cladding layer and at least one further layer of the base layer region located above is designed as a layer applied to the outer cladding layer. Such a multi-layer base layer region can, for example, be produced or manufactured by first carrying out at least a section-wise treatment of the cladding layer, for example by means of plasma treatment, UV treatment, arc discharge and / or chemical treatment and then coating the cladding layer using a coating process. The treatment in particular increases the surface energy on the one hand and preferably generates free oxygen radicals, which ensure good adhesion of subsequent coatings.The treatments are preferably applied to the entire fiber surface, i.e., the surface of the optical fiber with the cladding layer. Additional layers can be applied to the layer applied by coating processes.

[0057] A base layer region preferably has a thickness between 5 nm and 3000 nm, more preferably between 5 nm and 1000 nm, and particularly preferably between 10 nm and 100 nm. Furthermore, the individual layers of a base layer region can each have a thickness between 5 nm and 1000 nm, preferably between 10 nm and 100 nm. For example, a base layer region with at least two layers can be provided, wherein the lower layer is formed as a superficial layer of the outer cladding layer and a layer with a thickness between 5 nm and 1000 nm, preferably between 10 nm and 100 nm, is applied above it. The layer thickness can be determined depending on the thermal expansion coefficient of the optical fiber to be coated or its outer polymer layer in comparison to the thermal expansion coefficient of the conductive layer.

[0058] A base layer area can in particular be designed as an adhesion promoter layer. Accordingly, it can be provided that there is greater adhesion between the base layer area and the conductive layer applied to it than would exist between the outer jacket layer and an identical conductive layer applied to this. Good adhesion is achieved, for example, if a so-called tape test (printing ink adhesion) based on ASTM F 2252 / Sun Chemical-Hartmann PV 01 can be met. In this test, an adhesive strip is applied to the coated fibers and pulled off evenly at a defined angle. If there is no coating on the adhesive strip after removal and no delamination is apparent in the coating, the test is considered passed. Adhesion can also be checked with an adhesion test according to DIN 58196-6 (1995-07).In other words, increased adhesion can exist between the conductive layer, in particular the lowermost layer of the conductive layer, and the underlying uppermost layer of a base layer region, which can be formed as a superficial layer of the outer cladding layer with increased surface energy and / or increased number of oxygen radicals or as a layer applied to the cladding layer by coating. It is also possible for a base layer region to consist of a plurality of layers, wherein at least one or each layer applied above the lowermost layer has higher adhesion to the underlying layer than it would have to the layer located below the underlying layer.

[0059] Furthermore, a base layer region can be designed as a barrier layer. Accordingly, it can be provided that a base layer region, in particular at least one of the layers of the base layer region applied by coating to the outer cladding layer, inhibits or blocks the diffusion of polymer components, for example acids and / or oxygen, and in particular of ions of acidic or alkaline solutions, into the conductive layer. The base layer region can therefore delay or prevent the permeation of, for example, acids, oxygen, or other air components into the lower surface of the conductive layer. Alkaline cleaners or disinfectants can be used, particularly in the processing of medical products (e.g., NEODISHER with a pH value of approximately 11). Furthermore, the rinsing agent sodium hypochlorite (NaClO), a bleaching agent, or even a disinfectant can be used.

[0060] A base layer region preferably has a thermal expansion coefficient that lies between the thermal expansion coefficient of the cladding layer and the thermal expansion coefficient of the conductive layer. For a given thermal expansion coefficient (CTE) of the cladding layer, which can be in the range of > 15*E-6 1 / K, for example, the properties of the base layers can be selected depending on the conductive layer used. If, for example, a molybdenum coating is used as the conductive layer, which typically has a CTE of 5-6*E-6 1 / K, a base layer region with a higher CTE can be selected. As an example, a TiO2 coating with a CTE of 7-8*E-6 1 / K can then be suitable. It can preferably be provided that the thermal expansion coefficient of the cladding layer is greater than the thermal expansion coefficient of the base layer region.Furthermore, it can be provided that the thermal expansion coefficient of a base layer region is greater than or equal to the thermal expansion coefficient of the conductive layer. In a multi-layer base layer region, this applies to at least one of its layers. Furthermore, it can be provided that a base layer region comprises a sequence of layers, each having a thermal expansion coefficient that increases or decreases according to the sequence of the layers. A gradient of the thermal expansion coefficient (CTE) can also be achieved by quasi-continuously changing the composition. The selection of materials for a base layer region can be determined depending on the thermal expansion coefficient of the optical fiber to be coated or its outer polymer layer in comparison to the thermal expansion coefficient of the conductive layer.

[0061] A conductive layer applied to the base layer region preferably comprises a layer with titanium, silicon (optionally doped with n- or p-conducting dopants to increase the intrinsic conductivity), aluminum, gold, silver, molybdenum, tungsten or zirconium, in particular an alloy of one of these materials with Ni, Zn, Y, Sn, Ge or a sequence of such layers. Ti and Mo have proven to be particularly preferred. A layer with or made of molybdenum is therefore, for example, particularly preferred. In other words, the conductive layer can consist of a single layer or of a sequence of layers, wherein at least one layer is made of titanium, (doped) silicon, aluminum, gold, silver, molybdenum, tungsten, zirconium or of alloys made of at least one of the aforementioned conductive materials, Ni and its alloys, Zn, Y, Sn, Ge.Such a layer or layer sequence can, for example, be produced or manufactured by a coating process, as explained in more detail below.

[0062] A conductive layer applied to the base layer area can also include or consist of Ag, Cu, Cr, Ni, ITO, although in the medical technology sector, requirements of biocompatibility and cytotoxicity (ISO 10993-5:2009) may have to be observed.

[0063] The conductive layer preferably has a thickness between 5 nm and 6000 nm, more preferably between 5 nm and 2000 nm, and particularly preferably between 10 nm and 200 nm. Furthermore, at least one of the layers or each of the layers of the conductive layer can have a thickness between 5 nm and 2000 nm, preferably between 10 nm and 200 nm. The layer thickness can be determined depending on the desired electrical resistance or sheet resistance, with the sheet resistance within certain layer thickness ranges being inversely proportional to the layer thickness of the conductive layer. A layer thickness of at least 5 nm has the advantage of avoiding the risk of island formation (coating only in certain areas), thus creating a continuous layer. In the event of island formation, uniform conductivity is not achieved due to the insulating regions around the conductive "islands." However, layer thicknesses of at least 3 nm may also be sufficient.

[0064] The conductive layer preferably has a sheet resistance between 0.01 and 1000, preferably between 0.01 and 100, particularly preferably between 0.01 and 50 ohms / sqr (where the unit ohms / sqr corresponds to the unit ohm). Sheet resistance is the specific electrical resistance divided by the layer thickness. Examples of specific electrical resistance are: Ti: 8E-5 ohms cm, Si: 2 ohms cm, Au: 6E-8 ohms cm, Ag: 1E-5 ohms cm, Mo: 4.9 E-5 ohms cm. A thin 200 nm Ti coating has a sheet resistance of 3.9 ohms / sqr. This results in a specific resistance of 7.8*E-5 ohms*cm.

[0065] As already described above, a barrier layer (passivation layer) applied directly or indirectly to the conductive layer can also be provided. This barrier layer can consist of a single layer or a sequence of layers. The barrier layer is preferably designed to inhibit or block the diffusion of oxygen and / or acids / bases, in particular ions of acidic or alkaline solutions, into the conductive layer. Alkaline cleaners are sometimes used, particularly in the processing of medical products (e.g., NEODISHER with a pH value of approximately 11).

[0066] Sodium hypochlorite (NaClO), a bleaching agent, or disinfectant, can also be used. The barrier layer can therefore delay or prevent the permeation of acids, oxygen, or other atmospheric constituents, for example, into the upper surface of the conductive layer. Furthermore, the barrier coating can reduce mechanical attack on the conductive layer or fiber, thus forming a mechanical protective film. In combination with an appropriate base layer, the conductive layer can thus be protected on both sides from unwanted diffusion.

[0067] Preferably, the barrier layer or at least one of the layers of the barrier layer has a hardness of at least 800 HV, preferably at least 1200 HV, particularly preferably at least 2000 HV according to the test standard DIN EN ISO 14577-4:2007-8. The barrier layer can thus also be designed as a mechanical protective layer for the conductive layer, in particular for a metallic layer, and / or as protection for the optical fiber or the cladding layer (buffer material). Hard materials made of carbides or nitrides, for example, provide particular protection due to their increased hardness, such as AlN: HV up to approximately 2000, Si3N4: HV up to approximately 2500.

[0068] The barrier layer preferably comprises a layer applied to the conductive layer with a nitride, in particular Si3N4, BN, AlN, TiN, AlSiN, SiON, SiAlON or an alloy of one of these materials, or with an oxide, in particular oxides of Si, Al, Ti, Zr, Zn, Sn, Ta, Nb, Y or a ternary system of at least one of these materials, or with a carbide, boride, oxynitride, carbonitride, or a sequence of such layers applied to the conductive layer. Layers containing TiO2, TiN, Si3N4 or SiO2 have proven particularly suitable. Due to the CTE relationships mentioned above, barrier coatings with a comparable CTE to the conductive layer are preferred. In other words, the thermal expansion coefficient of the barrier layer can correspond to 0.5 to 2 times, preferably 0.75 to 1.25 times, the thermal expansion coefficient of the conductive layer. Furthermore, the barrier layer can consist of a single layer or a sequence of layers.Preferably, at least one layer of the barrier layer is made of nitride, e.g. Si3N4, BN, AIN, TiN, AlSiN or an alloy of one of the mentioned nitrides. Such a layer is particularly suitable for inhibiting the diffusion of atmospheric oxygen and also has the advantage of being relatively hard. Furthermore, at least one layer, in particular a further layer, is preferably made of oxide, in particular oxides of Si, Al, Ti, Zr, Zn, Sn, Ta, Nb, or a ternary system of at least one of these substances. Such a layer forms a particularly good barrier against acids. Carbides, borides, oxynitrides or carbonitrides can be used for one of the layers, preferably a further layer. Furthermore, the materials that can also be used for the base layer region can in principle also be used for the barrier layer and / or one of the layers of the barrier layer, wherein these materials differ in particular according to the chemical orAtmospheric requirements for such an optical-electrical conductor arrangement / fiber or for components with such an optical-electrical conductor arrangement / fiber. A layer or layer sequence can be produced or manufactured, for example, by a coating process, as explained in more detail below.

[0069] A base layer region, the conductive layer and / or a barrier layer, if present, extend at least partially or in sections in the axial direction of the optical waveguide.

[0070] A base layer region can have an amorphous structure, particularly if the base layer region is formed as a superficial partial layer of the cladding layer. A base layer region can also have a crystalline or polycrystalline structure, particularly if the base layer region comprises a layer applied by coating. The conductive layer and / or any barrier layer present can also have a crystalline or polycrystalline or possibly also an amorphous structure. Amorphous layers are preferred for the base layer region and barrier layer in order to ensure a particularly good diffusion barrier. Typical examples of amorphous diffusion barriers are SiO2, Si3N4, Al2O3, AlSiOx or BN; typical examples of crystalline barrier coatings are anatase or rutile TiO2, γ-Al2O3 or crystalline AIN. In particular, mixed phases of amorphous and crystalline phases should also be mentioned.

[0071] The optical-electrical conductor arrangement can at least partially or in sections have a tubing, i.e., be surrounded by a final outer sheath, wherein this final outer sheath can be designed to be tightly or loosely enclosing. Provision can be made for a distal section of the optical-electrical conductor arrangement to be stripped or remain stripped. The tubing can therefore extend predominantly along the optical-electrical conductor arrangement, but a portion of the optical-electrical conductor arrangement, in particular one end of the arrangement, has no tubing.

[0072] The invention further relates to a device for detecting the immersion of an optical-electrical conductor arrangement into a conductive medium, in particular within an animal or human body, wherein the device comprises an optical-electrical conductor system and an evaluation unit.

[0073] The optical-electrical conductor system is designed in particular according to the above statements. It comprises at least: an optical-electrical conductor arrangement comprising an optical waveguide with an outer, organic cladding layer, and a conductive layer applied directly or indirectly to the outer cladding layer of the optical waveguide; and further: an adapter sleeve that is at least partially electrically conductive, which mechanically grips the optical-electrical conductor arrangement and electrically contacts its conductive layer, such that the optical-electrical conductor arrangement can be immersed in the conductive medium.

[0074] The evaluation unit is electrically connectable or connected to the adapter sleeve, which is electrically conductive at least in some regions, and to one, in particular distal, end of the optical-electrical conductor arrangement and / or the conductive medium, and is configured to determine an impedance or impedance change between the adapter sleeve and the end of the optical-electrical conductor arrangement and / or the medium when the optical-electrical conductor arrangement is or becomes immersed in the conductive medium. In this way, immersion of the optical-electrical conductor arrangement into the medium can be detected and / or an immersion depth of the optical-electrical conductor arrangement into the medium can be determined.

[0075] Furthermore, the device for detecting immersion can be configured such that, when immersion of the optical-electrical conductor arrangement into the medium is detected and / or that the coupling of light into the optical fiber is controlled depending on the immersion depth. For example, the coupling of light can be activated as soon as the optical-electrical conductor arrangement is immersed in the medium or has been immersed sufficiently far. For this purpose, the device can optionally comprise a device or a handpiece with a connection socket for inserting the adapter sleeve and a light source for coupling light into the optical fiber.

[0076] The invention further relates to a method for producing an optical-electrical conductor system, in particular as described above.

[0077] In this case, an adapter sleeve that is electrically conductive at least in certain regions is provided or produced. Furthermore, an optical-electrical conductor arrangement is provided or produced such that the optical-electrical conductor arrangement at least comprises: an optical waveguide with an outer, organic cladding layer, and a conductive layer consisting of a single layer or a sequence of layers, applied directly or indirectly to the outer cladding layer of the optical waveguide. The optical-electrical conductor arrangement is then inserted into the adapter sleeve such that the adapter sleeve mechanically grips the optical-electrical conductor arrangement and electrically contacts its conductive layer.

[0078] Preferably, the provided or manufactured adapter sleeve comprises a fixing portion to mechanically grip the optical-electrical conductor arrangement, and an adhesive is introduced into the fixing portion to additionally fix the optical-electrical conductor arrangement.

[0079] In addition, the provided or manufactured adapter sleeve preferably comprises an electrically conductive contacting section in order to electrically contact the conductive layer of the optical-electrical conductor arrangement, and an electrically conductive adhesive is introduced into the contacting section in order to electrically contact the conductive layer of the optical-electrical conductor arrangement.

[0080] The following will discuss the production of the optical-electrical conductor arrangement itself in more detail.

[0081] The production of an optical-electrical conductor arrangement may be provided, wherein an optical waveguide is provided with an outer cladding layer, and the cladding layer of the optical waveguide is coated with a functional layer system. Coating with the functional layer system comprises first creating a base layer region consisting of a single layer or a sequence of layers and then applying (onto the base layer region) an electrically conductive layer consisting of a single layer or a sequence of layers.

[0082] The creation of the base layer region can, on the one hand, comprise pretreating the cladding layer of the optical waveguide in order to create a superficial layer with at least one modified surface property, in particular an increased surface energy and / or an increased number of oxygen radicals, and / or to remove residues. The creation of the base layer region can, on the other hand, comprise applying (to the outer cladding layer) a layer or a sequence of layers, wherein in particular cathode sputtering, high-frequency sputtering, reactive sputtering and / or magnetron sputtering are used. In addition to cathode sputtering (sputtering), other coating processes, in particular vacuum processes (e.g., vapor deposition, chemical vapor deposition (CVD, e.g., PECVD, in particular, PICVD)) can also be used.Other coating methods for applying one or more layers of the base layer include liquid-phase processes such as dip coating or spray coating. These can also incorporate additional functionalities, such as friction reduction.

[0083] Pretreatment of the cladding layer to form the base layer or, for example, the lowest layer of the base layer can be achieved using chemical or physical processes to change the surface properties of the cladding layer. Pretreatment of the cladding layer, i.e. the surface to be coated, enables good layer adhesion. In particular, plasma pretreatment (low-pressure plasma or atmospheric plasma), arc discharge (corona) and / or chemical pretreatment, e.g., using alkaline cleaners in an ultrasonic bath, can generate high surface energies, at least temporarily, so that adhesion can be significantly improved. Plasmas can also be used to remove grease, oil or similar residues and to activate oxygen radicals. However, pretreatment methods can also be combined.

[0084] It can also be provided that a lower layer of the base layer region is first formed by pretreating the cladding layer of the optical waveguide as described above, and then at least one further layer of the base layer region is applied to this lower layer, in particular using the aforementioned sputtering methods (or other coating methods). In particular, this method step can produce a base layer region as described in connection with the optical-electrical conductor arrangement.

[0085] The electrically conductive layer is preferably applied to the base layer region by means of cathode sputtering, high-frequency sputtering, reactive sputtering, and / or magnetron sputtering. In addition to cathode sputtering, other coating processes, particularly vacuum processes (e.g., vapor deposition, chemical vapor deposition (CVD, e.g., PECVD, especially PICVD)), can also be used. This process step can, in particular, be used to apply a conductive layer to the base layer region, as described in connection with the optical-electrical conductor arrangement.

[0086] Coating the cladding layer with a functional layer system can further comprise applying a barrier layer (passivation layer) to the conductive layer, wherein the barrier layer can be applied as a single layer or as a sequence of layers and, for this purpose, in particular cathode sputtering, high-frequency sputtering, reactive sputtering and / or magnetron sputtering (or other coating processes, such as the aforementioned vacuum processes or the aforementioned processes from the liquid phase, such as dip coating or spray coatings) can be used. The barrier layer can also serve to reduce the coefficient of friction. With this method step, in particular a barrier layer can be applied to the conductive layer, as described in connection with the optical-electrical conductor arrangement.

[0087] The coating processes mentioned, in particular cathode sputtering processes, with which layers of the base layer, the conductive layer, and / or the barrier layer can be applied, are preferably carried out at temperatures below 50°C. This relatively low temperature has the particular advantage that optical fibers can be coated with an outer polymer layer.

[0088] Preferably, the production and / or application of at least two layers takes place in a vacuum and without vacuum breakage. Thus, for example, the base layer region can be produced first in a vacuum, and then the conductive layer can be applied in the same vacuum. Furthermore, a barrier layer can then be applied in the same vacuum.

[0089] Furthermore, a medical device may be provided, in particular an endoscope, in particular for dental treatment, comprising an optical-electrical conductor system as described above. Such a medical device may, for example, be designed as a medical fiber component with an optical-electrical conductor system comprising an optical waveguide, such as a quartz fiber, wherein the optical waveguide is coated with a conductive layer or a functional layer system. Such a device may, for example, be designed for endoscopic applications or applications in the dental field (dental treatment).

[0090] Furthermore, an industrial device can be provided, in particular a device for level monitoring, in particular for containers or bioreactors, comprising an optical-electrical conductor system as described above. Such an industrial device can be provided, for example, for industrial applications, e.g., for level sensors in containers, bioreactors, or safety monitoring systems. In particular, level monitoring is enabled in which an impedance change can be detected and evaluated depending on whether the fiber is immersed in a medium or not. In addition, penetration depth measurement is enabled in which an impedance change can be detected and evaluated depending on how far the fiber is immersed in a surrounding medium.

[0091] Finally, the use of an optical-electrical conductor system can be provided for industrial applications, in particular applications for level monitoring or safety monitoring, or the use of an optical-electrical conductor system for measuring a penetration depth of the optical-electrical conductor arrangement into a medium by measuring an impedance of the conductive layer in the surrounding medium.

[0092] Exemplary embodiments of the invention are described below with reference to the figures. In the figures: Fig. 1: a cross-section through an optical-electrical conductor arrangement (1) with an optically conductive core (11), a sheath (12), a cladding layer (13) and a functional layer system (20), Fig. 2: a cross-section through an optical-electrical conductor arrangement (1) with an optically conductive core (11), a cladding layer (13) and a functional layer system (20), Fig. 3: a cross-section through a device for immersion detection (200) comprising an optical-electrical conductor system (100) with an optical-electrical conductor arrangement (1) and an adapter sleeve (30) which mechanically detects the optical-electrical conductor arrangement (1) and electrically contacts its conductive layer (22), Fig. 4a: Equivalent circuit diagram for the total impedance of an optical-electrical conductor system (100), Fig. 4b: Simplified equivalent circuit diagram for the total impedance of an optical-electrical conductor system (100),

[0093] Fig.1 shows an optical-electrical conductor arrangement 1 with an optical waveguide 10 with a diameter of 10.1. The optical waveguide 10 has a core 11 made of quartz glass and a cladding 12, also made of quartz glass. The refractive index n1 of the core 11 is greater than the refractive index n2 of the cladding 12. Additionally, and particularly as mechanical protection, a cladding layer 13 (buffer) designed as a polymer layer / polymer cladding is provided. As is customary for such optical waveguides, the cladding layer 13 comprises polyimide, PMMA, or polyamide, or consists of at least one of these materials.

[0094] The optical-electrical conductor arrangement 1 has a functional layer system 20 on the cladding layer 13, which in this example consists of a base layer region 21 formed as an adhesion promoter layer directly on the cladding layer 13, a conductive layer 22, and an outer barrier layer (passivation layer) 23. The functional layer system 20 on the outer cladding layer 13 can be produced by cathode sputtering or another vacuum process (e.g., vapor deposition). The functional layer system 20 has a layer thickness of 20.1.

[0095] Fig.Figure 2 shows an optical-electrical conductor arrangement 1 with an optical waveguide 10. In this case, the optical waveguide 10 has a core 11 and a cladding layer 13 directly surrounding the core 11. The refractive index n1 of the core 11 is in this case slightly higher than the refractive index n2 of the cladding layer 13. The cladding layer 13 thus enables total reflection at the interface to the core 11 and thus light transmission. At the same time, the cladding layer 13 can serve as a mechanical protective layer.

[0096] The optical-electrical conductor arrangement 1 further comprises a functional layer system 20, which can be designed and manufactured in the same way as in the Fig. 1.

[0097] As already explained, the functional layer system 20 can comprise several individual layers. These are a base layer region 21 formed as an adhesion promoter layer, the actual conductive layer 22, and an optional barrier layer (passivation layer) 23. With regard to the production of such an optical-electrical conductor arrangement, the entire layer sequence can be carried out consecutively in a batch cycle without interrupting the vacuum process, so that several components with such optical-electrical conductor arrangements 1 can be coated in parallel and cost-effectively.

[0098] Further embodiments of the production of an optical-electrical conductor arrangement are described below.

[0099] Example 1: Optical-electrical conductor arrangement 1 with an optical waveguide 10 designed as a quartz fiber with a core 11 whose diameter is 150µm, a cladding 11 whose diameter is 180µm and a cladding layer 13 made of polyimide designed as a polymer layer with an outer diameter of the optical waveguide 10 of a total of approximately 210µm.

[0100] A base layer area was created by subjecting the cladding layer to a pretreatment process. Ultrasonic cleaning with an alkaline and a neutral cleaner, and IR drying were used.

[0101] A conductive layer consisting of a 15 nm thick titanium coating was applied using DC magnetron sputtering. The coating was carried out in a vacuum at a process pressure of less than 1E-2 mbar. The sputtering target was selected with a purity of 99%. The minimum distance between the substrate and the target was set at 5 cm, with the optical fiber extending into the plasma.

[0102] Using a 4-point measuring device for determining sheet resistance, a value of 10 ohms / sqr (where the unit ohms / sqr corresponds to the unit ohm) was measured. This corresponds to a specific resistance of 1.5 ohms / cm. The adhesion of the coating system was tested using an adhesion test according to DIN 58196-6 (1995-07). This test showed no detachment of the functional coating system from the optical fiber.

[0103] Example 2: A quartz fiber optic cable with a polyimide cladding layer was cleaned and preactivated using an atmospheric plasma in the form of a corona discharge. Subsequently, a silicon oxide coating was applied using a reactive medium-frequency plasma, which was then coated with a conductive molybdenum coating with a layer thickness of 24 nm without vacuum break. This layer was then passivated without vacuum break using reactive magnetron sputtering with a silicon nitride coating with a layer thickness of 100 nm.

[0104] In a subsequent sheet resistance test, a sheet resistance of 5 ohms / sqr was determined using an inductive measuring method, an eddy current meter. According to the adhesion test mentioned above, no delamination was detected.

[0105] Example 3: A quartz fiber optic cable with a polyimide cladding layer is cleaned using ultrasonic cleaning as per Example 1. The conductive layer, applied directly to the cladding layer, comprises molybdenum with a sheet resistance of 10 ohms / sqr. A barrier coating of TiO2 is optionally applied to protect the molybdenum coating. Both coatings are produced using a magnetron sputtering process in a vacuum, with the optical fibers extending into the plasma, thus creating a nearly homogeneous coating. In the case of the molybdenum coating, the coatings are applied from a metallic sputtering target of 3N purity; in the case of the TiO2 coating, from a metallic target or a partially ceramic target with the addition of oxygen. In this case, the TiO2 coating is partially amorphous and partially anatase.In a subsequent mechanical stress test, in which aluminum test specimens with a mass of 22.5 g are pulled over the length of the optical fibers, light microscopic images at up to 100x magnification show no scratches or delamination of the metallic coating.

[0106] Example 4: In a further embodiment, an optical waveguide constructed as a quartz fiber with a polyimide cladding layer is pretreated by wet-chemical cleaning. Layers of both the base layer and the conductive layer are then applied with the addition of oxygen and argon. To ensure improved adhesion between the cladding layer and the conductive layer, an adhesion promoter layer made of TiO2 is formed between them. For this layer, the ratio of oxygen to the total flow of oxygen and argon is less than 0.4. A metallic titanium coating with a sheet resistance of 1 ohm / sqr is then applied as a conductive coating. For this layer, the ratio of oxygen to the total flow of oxygen and argon is less than 0.1.As an additional passivation, another TiO2 coating is applied, whereby the ratio of oxygen to the total flow of oxygen and argon is less than 0.7.

[0107] The ratio of oxygen to the total flux (see exemplary ratios above) indicates how close the result is to the metallic character or the dielectric character of the TiO2 layer.

[0108] Fig.3 shows a device 200 for detecting the immersion of an optical-electrical conductor arrangement 1 of an optical-electrical conductor system 100 into a conductive medium 50. Such a device 200 thus corresponds to a preferred application of such an optical-electrical conductor arrangement 1 for determining the fill level or for determining a penetration depth 22.3 into a conductive liquid 50. For this purpose, the optical waveguide 10 with its functional layer system 20 is fastened in an electrically conductive adapter sleeve 30 and together with this forms an optical-electrical conductor system 100. In the exemplary embodiment shown, the adapter sleeve is connected to an electrical evaluation unit 60 with which alternating voltage signals for impedance measurement can be coupled into the sleeve at a specific frequency f. Furthermore, the evaluation unit 60 is connected via the ground or directly, as in Fig. 3, conductively connected to the liquid 50.

[0109] The electrically conductive adapter sleeve 30, which can be made of stainless steel or nickel silver, for example, has a fixing section 31 with its diameter 31.1 and its length 31.2 for receiving the optical-electrical conductor arrangement 1. Furthermore, the adapter sleeve 30 can have a separate contacting section 32 with its diameter 32.1 and its length 32.2. The diameters 31.1 and 31.2 as well as the lengths 31.2 and 32.2 can differ. The fixing section 31 preferably has a small diameter 31.1, which is only slightly larger than the diameter of the complete optical waveguide 10 with its functional layer system 20, so that when bonded with an adhesive 40, a position with the closest possible tolerance and with a small centricity error can be achieved, thus ensuring optimal light coupling into the optically conductive core 11 of the optical waveguide 10 (cf. Fig.1 or 2). Typically, laser light focused onto the core 11 is coupled in. Special, very thin adhesives 40 are often used for this purpose, which, due to capillary action, can fill the resulting adhesive gap.

[0110] However, for electrical coupling, it may be necessary to additionally provide a conductive adhesive 41 in the contacting section 32. This type of adhesive is typically a silver-filled epoxy adhesive, which, however, requires a larger adhesive gap. Therefore, the diameter 32.1 of the contacting section 32 of the adapter sleeve 30 is larger than the diameter 31.1 of the fixing section 31 of the adapter sleeve 30.

[0111] The optical-electrical conductor system, i.e., the optical-electrical conductor arrangement 1 with the adapter sleeve 30 and the adhesives 40, 41 used, now form an impedance dependent on the frequency f, which changes upon contact with the liquid 50 or upon immersion in it. When contacting the optical-electrical conductor arrangement 1 in the adapter sleeve 30, care must be taken to ensure the lowest possible transition impedances, both capacitive and due to ohmic conduction, in order to enable sufficiently sensitive detection of the liquid level or the immersion depth 22.3.

[0112] If one considers this arrangement at typical frequencies in the range of a few hundred Hertz to about 100 kHz, inductive impedances can be neglected, so that an electrical equivalent circuit essentially consists of ohmic resistors and capacitors, which result in the frequency-dependent total impedance Z.

[0113] This allows an approximate equivalent circuit diagram to be sketched, as shown in Fig. 4a. It includes: R 30 Ohmic resistance of sleeve 30 (relatively low resistance, in the mΩ range) R 40 Ohmic resistance of the adhesive gap for the adhesive 40 between optical fiber 10 with functional layer system 20, depending on the adhesive layer thickness 40.1 d K40Q and the adhesive gap length 40.2 I K40Q and the specific resistance ρ K40 of the adhesive 40 (this is comparatively high-resistance), C 40 Capacity of the adhesive gap with the adhesive 40, depending on the adhesive layer thickness 40.1 d K40Q , the adhesive gap length 40.2 I K40Q and the total diameter d Fg of the optical fiber 10 including the functional layer system 20 d Fg and the relative dielectric constant ε K40 of the adhesive 40 R 41Ohmic resistance of the adhesive gap for the conductive adhesive 41 between optical fiber 10 with functional layer system 20, depending on the adhesive layer thickness 41.1 d K41Q and the adhesive gap length 41.2 I K41Q and the specific resistance ρ K41 of the conductive adhesive 41 (this is comparatively low-resistance), C 41 Capacity of the adhesive gap with the conductive adhesive 41, depending on the conductive adhesive layer thickness 41.1 d K41Q and the adhesive gap length 40.2 I K41Q and the relative dielectric constant ε K41 of the conductive adhesive 41 R 23 / 40 Ohmic resistance of the barrier layer 23 of the functional layer system 20 in the area of bonding with the adhesive 40, depending on its barrier layer thickness 23.1 d 23 and the adhesive gap length 40.2 I K40Q and the specific resistance of the barrier layer 23 ρ 23 (usually very high resistance) C 23 / 40Capacity of the barrier layer 23 of the functional layer system 20 in the area of bonding with the adhesive 40, depending on its barrier layer thickness 23.1 d 23 and the adhesive gap length 40.2 I K40Q and the relative dielectric constant ε 23 the barrier layer 23. R 23 / 41 Ohmic resistance of the barrier layer 23 of the functional layer system 20 in the area of bonding with the conductive adhesive 41, depending on its barrier layer thickness 23.1 d 23 and the adhesive gap length 41.2 I K41Q and the specific resistance of the barrier layer 23 ρ 23 (usually very high resistance) C 23 / 41 Capacity of the barrier layer 23 of the functional layer system 20 in the area of bonding with the conductive adhesive 41, depending on its barrier layer thickness 23.1 d 23 and the adhesive gap length 41.2 I K40Q and the relative dielectric constant ε 23 the barrier layer 23. R22 Ohmic resistance of the conductive layer 22, depending on the conductive layer thickness d 22 and conductive layer length 22.2 I 22 and the specific resistance of the conductive layer 22 ρ 22 , which is comparatively low-resistance. R 23(E) Ohmic resistance of the barrier layer 23 depending on immersion depth 22.3 E and barrier layer thickness 23.1 d 23 and the specific resistance of the barrier layer 23 ρ 23 C 23(E) Capacity of the barrier layer 23 of the functional layer system 20 in the area of immersion, depending on its barrier layer thickness 23.1 d 23 and the immersion depth 22.3 E and the relative dielectric constant ε 23 the barrier layer 23.

[0114] This equivalent circuit in Fig. 4a can be simplified in that the ohmic resistance R 30of the adapter sleeve 30 is almost negligible, as it is in the mΩ range. Furthermore, the ohmic resistance of the adhesive gap R 40 for the Keber 40, it is comparatively high-resistance and therefore contributes very little to the total impedance. This also applies to the ohmic resistance R 23 / 40 the barrier layer 23 in the area of the adhesive 40. The same applies to the ohmic resistance R 23 / 41 the barrier layer 23 in the area of the conductive adhesive 41. On the other hand, the capacitive part of the adhesive gap C 41 with the conductive adhesive 41 opposite R 41 can be neglected. Likewise, the ohmic resistance R 23(E) of the barrier layer 23 depending on the immersion depth 22.3 E can be neglected, since this part contributes very little to the conductivity due to the high resistance of the barrier layer 23. This results in the simplified equivalent circuit in Fig. 4b for the total impedance Z.

[0115] The individual impedances from the simplified equivalent circuit in Fig. 4b are calculated as follows: C40=ε0εK40πdFgIK40Q / dK40Q C23 / 40=ε0ε40π(dF+2dL)IK40Q / d23 with d F equal to the diameter 10.1 of the optical fiber 10 including the conductive layer thickness 22.1 d L of the functional layer system 20 and the barrier layer thickness 23.1 d 23 R41=ρK41 dK41Q / (π IK41Q dFg) C23 / 41=ε0ε23π(dF+2dL)IK41Q / d23 R22=ρ22 4 IF / (((dF+2 d22)2−dF2)π) C23(E)=ε0ε23π dFg E / d23

[0116] According to one embodiment, the following individual impedances result for a functional layer system 20 with a conductive layer 22 made of titanium (Ti) and a barrier layer 23 made of TiO2, taking into account the following geometries, material constants and frequencies f: First frequency f1: 1.000 1 / s Second frequency f2: 10.000 1 / s Diameter 10.1 optical fiber 10: 265 µm = 2.65 E-4 m Conductive layer thickness 22.1 of the Ti conductive layer: 0.4 µm = 0.4 E-6 m Barrier layer thickness 23.1 made of TiO2: 100 nm = 0.1 E-6 m Adhesive layer thickness 40.1 of adhesive 40: 20 µm = 2 E-5 m Adhesive gap length 40.2 for adhesive 40: 0.8 mm = 8 E-4 m Adhesive layer thickness 41.1 of the conductive adhesive 41: 0.1 mm = 1 E-4 m Adhesive gap length 41.2 for the conductive adhesive 41: 1.5 mm = 1.5 E-3 m Conductive layer length 22.2: 50 mm = 5 E-2 m ε0: 8.85 E-12 As / Vm e 23 : 180 e 40 : 10 r 22 : 4.0 E-7 Ohm m r 41 : 1.0 E-6 Ohm m First immersion depth 22.3 E 0 mm (fiber end just touches the liquid 50) Second immersion depth 22.3 E: 10 mm = 1 E-2 m Third immersion depth 22.3 E: 20 mm = 2 E-2 m C40=3.0 pF C23 / 40=11 nF R41=0.08 mΩ C23 / 41=20 nF R22=60Ω C23(E=0)=0 F

[0117] For an immersion depth E = 10 mm = 1 E-2 m C23(E=10)=0.13 μF

[0118] For an immersion depth E = 20 mm = 2 E-2 m C23(E=20)=0.27 μF

[0119] This results in the following frequency-dependent absolute individual impedances, where XC i capacitive reactive power resistors and ZR i represent real ohmic resistances with XCi=1 / ω Ci=1 / (2 π f Ci) ZRi=Ri

[0120] For the first frequency f1 = 1 kHz the following values result XC 40 = 54 MΩ XC 23 / 40 = 15 kΩ ZR 41 = 0.08 mΩ XC 23 / 41 = 8 kΩ ZR 22 = 60 Ω XC23(E=0 mm) extremely high impedance XC23(E=10 mm) 1.2 kΩ XC23 (E=20 mm) 600 Ω

[0121] For the second frequency f2 = 10 kHz the following values result XC 40 = 5.4 MΩ XC 23 / 40 = 1.5 kΩ ZR 41 = 0.08 mΩ XC 23 / 41 = 800 Ω ZR 22 = 60 Ω XC 23(E=0 mm) extremely high impedance X C23(E=10 mm) 120 Ω XC 23(E=20 mm) 60 Ω

[0122] The example values show that with appropriate frequency selection and use of a conductive adhesive 41 in the contact section 32, quite good impedance ratios occur, so that a fill level detection or measurement of the penetration depth 22.3 E is possible with comparatively simple electronic effort within the evaluation unit 60.

[0123] It will be apparent to those skilled in the art that the embodiments described above are to be understood as examples and that the invention is not limited to them, but can be varied in many ways without departing from the scope of the claims. Furthermore, the features of the optical-electrical conductor arrangement are also disclosed in a corresponding manner as features for the method for producing an optical-electrical conductor arrangement, and vice versa. Features, regardless of whether they are disclosed in the description, the claims, the figures, or otherwise, also individually define components of the invention, even if they are described together with other features. List of reference symbols 100 Optical-electrical conductor system 1 Optical-electrical conductor arrangement 10 optical fibers 10.1 Diameter 11 Optically conductive core 12 Wrapping 13 Organic mantle layer 20 functional layer system 20.1 Layer thickness 21 Base layer area 22 Conductive layer 22.1 Conductive layer thickness 22.2 Conductive layer length 22.3 Immersion depth 23 Barrier layer 23.1 Barrier layer thickness 30 adapter sleeve 31 Fixation section 31.1 diameter 31.2 Length 32 Contact section 32.1 diameter 32.2 length 40 glue 40.1 Adhesive layer thickness 40.2 Adhesive gap length 41 conductive adhesive 41.1 Conductive adhesive layer thickness 41.2 Adhesive gap length 50 liquid 60 evaluation unit 200 Device for detecting immersion

Claims

[1] Optical-electrical conductor system (100) comprising: an optical-electrical conductor arrangement (1) comprising an optical waveguide (10) with an outer, organic cladding layer (13), and a conductive layer (22) applied directly or indirectly to the outer cladding layer (13) of the optical waveguide (10) as a coating, consisting of a single layer or a sequence of layers, and an adapter sleeve (30) which is at least partially electrically conductive and which mechanically grips the optical-electrical conductor arrangement (1) and electrically contacts its conductive layer (22), in particular in such a way that the optical-electrical conductor system (100) with the adapter sleeve (30) can be inserted into a connection socket for transmitting optical and / or electrical signals, e.g. arranged on a handpiece, wherein the adapter sleeve (30) has an electrically conductive contacting section (32) which electrically contacts the conductive layer (22) of the optical-electrical conductor arrangement (1), wherein an electrically conductive adhesive (41) is introduced into the contacting section (32) and electrically contacts the conductive layer (22) of the optical-electrical conductor arrangement (1). [2] Optical-electrical conductor system (100) according to claim 1, wherein the adapter sleeve (30) an outer sleeve body which encloses an inner receiving opening and wherein the adapter sleeve (30) defines a sleeve axis, and wherein the optical-electrical conductor arrangement (1) extends along the sleeve axis through the inner receiving opening of the adapter sleeve (30). [3] Optical-electrical conductor system (100) according to claim 2, wherein the inner receiving opening of the adapter sleeve (30) is cylindrically shaped and / or arranged concentrically to the outer sleeve body. [4] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the optical-electrical conductor arrangement (1) protrudes from the adapter sleeve (30) on at least one side and / or is held in the adapter sleeve (30) in such a way that at least the optical waveguide (10) is accessible from both sides of the adapter sleeve (30). [5] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the adapter sleeve (30) has a fixing section (31) which mechanically grips the optical-electrical conductor arrangement (1) and wherein an adhesive (40) is preferably introduced into the fixing section (31), which additionally fixes the optical-electrical conductor arrangement (1) and wherein the adhesive (40) has in particular a thickness of between 1 and 500 micrometers in the radial direction, preferably between 5 and 100 micrometers, particularly preferably between 10 and 50 micrometers. [6] Optical-electrical conductor system (100) according to claim 5, wherein the fixing section (31) grips the optical-electrical conductor arrangement (1) with a radial tolerance of less than 50µm, preferably less than 30µm, in particular in that the fixing section (31) has a radial play of less than 50µm, preferably less than 30µm, relative to the optical-electrical conductor arrangement (1) and / or wherein the fixing section (31) grips the optical-electrical conductor arrangement (1) in such a way that the optical waveguide (10) of the optical-electrical conductor arrangement (1) is gripped centrally to the sleeve axis with a concentricity error of less than 50µm, preferably less than 30µm. [7] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the conductive adhesive (41) in the radial direction has in particular a thickness between 1 and 500 micrometers, preferably between 25 and 250 micrometers, particularly preferably between 50 and 150 micrometers. [8] Optical-electrical conductor system (100) according to one of claims 5 to 7, wherein the inner receiving opening of the adapter sleeve has a smaller cross-section in the region of the fixing section (31) than in the region of the contacting section (32) and wherein the inner receiving opening preferably has a transition region from the smaller cross-section to the larger cross-section between the fixing section (31) and the contacting section (32) and where the transition area is designed, for example, as a cone or as a ring shoulder. [9] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the adapter sleeve (30) comprises or consists of a metal, e.g. stainless steel or nickel silver, or a conductive plastic or a conductive ceramic. [10] Optical-electrical conductor system (100) according to one of claims 1 to 9, where the ohmic resistance (R 30 ) of the adapter sleeve (30) is between 1 and 1000 milliohms, preferably between 10 and 1000 milliohms, particularly preferably between 10 and 100 milliohms and / or where the ohmic resistance (R 22) of the conductive layer (22) is between 1 and 1000 ohms, preferably between 10 and 500 ohms, particularly preferably between 10 and 100 ohms. [11] Optical-electrical conductor system (100) according to one of the preceding claims, wherein a barrier layer (23) is applied directly or indirectly to the conductive layer (22) applied directly or indirectly to the outer cladding layer (13) of the optical waveguide (10), wherein the barrier layer (23) is designed to inhibit the diffusion of oxygen and / or ions of acidic or alkaline solutions into the conductive layer (22), in particular in such a way that the electrically conductive contacting section (32) or the electrically conductive adhesive (41) introduced therein indirectly electrically contacts the conductive layer (22) of the optical-electrical conductor arrangement (1). [12] Optical-electrical conductor system (100) according to one of claims 1 to 11, wherein an impedance (Z) is measurable between the adapter sleeve (30) and the conductive layer (22) of the optical-electrical conductor arrangement (1) and wherein the impedance (Z) has a conductive layer portion which is formed by or at least dependent on the impedance of the conductive layer (22) and / or the impedance of the conductive layer (22) to a medium (50) surrounding the optical-electrical conductor arrangement (1) and wherein the impedance (Z) has a contacting component which is formed by or at least dependent on the ohmic resistance (R 41 ) of the conductive adhesive (41) introduced into the contacting section (32) and / or the capacitive resistance (C 41 ) of the conductive adhesive (41) introduced into the contacting section (32) and wherein the contacting portion of the impedance (Z) is less than or equal to 10 times, preferably less than or equal to 5 times, particularly preferably less than or equal to 0.5 times the conductive layer portion of the impedance (Z). [13] Optical-electrical conductor system (100) according to claim 12 when referring back to claim 5, wherein the contacting component of the impedance (Z) is further dependent on the ohmic resistance (R 40 ) of the adhesive (40) introduced into the fixing section (31) and / or the capacitive resistance (C 40 ) of the adhesive (40) introduced into the fixing section (31). [14] Optical-electrical conductor system (100) according to claim 12 or 13 when referring back to claim 11, wherein the contacting component of the impedance (Z) is further dependent on the ohmic resistance (R 23 / 40 ) of the barrier layer (23) in the region of the adhesive (40) introduced into the fixing section (31) and / or the capacitive resistance (C 23 / 40) of the barrier layer (23) in the region of the adhesive (40) introduced into the fixing section (31). [15] Optical-electrical conductor system (100) according to one of claims 12 to 14, wherein the impedance (Z) measurable between the adapter sleeve (30) and the conductive layer (22) of the optical-electrical conductor arrangement (1) between the outer sleeve body of the adapter sleeve (30) and a region of the conductive layer (22) in a section of the optical-electrical conductor arrangement (1) projecting from the adapter sleeve (30), preferably at the end, and / or is measurable at a specific evaluation frequency or over an evaluation frequency range, wherein the evaluation frequency or the evaluation frequency range is preferably in the range from 1 Hz to 10 GHz, more preferably in the range from 10 Hz to 2.4 GHz, even more preferably in the range from 100 Hz to 1 MHz, particularly preferably in the range from 1 kHz to 100 kHz and most preferably in the range from 1 KHz to 10 kHz. [16] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the optical-electrical conductor arrangement (1) comprises: the optical waveguide (10) with the outer, organic cladding layer (13), a functional layer system (20) located on the outer cladding layer (13) of the optical waveguide (10) with a base layer region (21) consisting of a single layer or a sequence of layers and the electrically conductive layer (22) consisting of a single layer or a sequence of layers, wherein the conductive layer (22) is applied to the base layer region (21). [17] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the optical waveguide (10) comprises: - an optically conductive core (11) and - preferably a sheath (12) which surrounds the core (11) and is arranged between the core (11) and the outer sheath layer (13), - and wherein the optically conductive core (11) has a refractive index which is greater than a refractive index which the outer cladding layer (13) has and / or is greater than a refractive index which the cladding (12) has. [18] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the organic cladding layer (13) comprises polyamide (PA), polyimide (PI) or polymethyl methacrylate (PMMA) or wax, wax-like components or alkylsilane. [19] Optical-electrical conductor system (100) according to one of claims 16 to 18 when referring back to claim 16, wherein the base layer region (21) comprises: - a layer applied to the outer cladding layer (13) with an oxide, in particular SiO2, TiO2, Al2O3, SnO2, HfO2 or a boride, carbide, nitride, oxynitride, carbonitride or a metal, in particular Si, Ti, Mo or Cr, - or a sequence of such layers applied to the outer cladding layer (13). [20] Optical-electrical conductor system (100) according to one of claims 16 to 19 when referring back to claim 16, wherein the base layer region (21) comprises or is formed by: - a superficial layer of the outer sheath layer (13) with at least one modified surface property, in particular an increased surface energy and / or an increased number of oxygen radicals, in particular produced or producible by means of a chemical and / or physical process for changing at least one surface property of the outer sheath layer (13). [21] Optical-electrical conductor system (100) according to one of claims 16 to 20 when referring back to claim 16, wherein the base layer region has a thickness between 5nm and 3000nm, preferably between 5nm and 1000nm, particularly preferably between 10nm and 100nm and / or wherein the individual layers of the base layer region each have a thickness between 5nm and 1000nm, preferably between 10nm and 100nm. [22] Optical-electrical conductor system (100) according to one of claims 16 to 21 when referring back to claim 16, wherein there is an adhesion between the base layer region (21) and the conductive layer (22) applied thereon which is greater than an adhesion which would exist between the outer cladding layer (13) and an identical conductive layer (22) applied thereon. [23] Optical-electrical conductor system (100) according to one of claims 16 to 22 when referring back to claim 16, wherein at least one of the layers of the base layer region (21) applied to the outer cladding layer (13) is designed to inhibit diffusion of oxygen and / or ions of acidic or alkaline solutions into the conductive layer (22). [24] Optical-electrical conductor system (100) according to one of claims 16 to 23 when referring back to claim 16, wherein the base layer region (21) has a thermal expansion coefficient which lies between a thermal expansion coefficient which the cladding layer (13) has and a thermal expansion coefficient which the conductive layer (22) has. [25] An optical-electrical conductor system (100) according to any one of claims 16 to 24 when referring back to claim 16, wherein the base layer region comprises a sequence of layers each having a thermal expansion coefficient which increases or decreases according to the sequence of layers. [26] Optical-electrical conductor system (100) according to one of claims 16 to 25 when referring back to claim 16, wherein the conductive layer (22) comprises: - a layer applied to the base layer region (21) with titanium, silicon, aluminium, gold, silver, molybdenum, tungsten or zirconium, in particular an alloy of one of these substances with Ni, Zn, Y, Sn, Ge - or a sequence of such layers applied to the base layer region (21). [27] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the conductive layer (22) has a thickness between 5nm and 6000nm, preferably between 5nm and 2000nm, particularly preferably between 10nm and 200nm and / or wherein individual layers of the conductive layer each have a thickness between 5nm and 2000nm, preferably between 10nm and 200nm. [28] Optical-electrical conductor system (100) according to one of the preceding claims, wherein the conductive layer (22) has a sheet resistance between 0.01 and 1000 Ohm / sqr, preferably between 0.01 and 100 Ohm / sqr, particularly preferably between 0.01 and 50 Ohm / sqr. [29] Optical-electrical conductor system (100) according to one of claims 16 to 28 when referring back to claim 16, wherein the functional layer system (20) further comprises: - a barrier layer (23) applied to the conductive layer (22) consisting of a single layer or a sequence of layers, wherein the barrier layer (23) is designed to inhibit the diffusion of oxygen and / or ions from acidic or alkaline solutions into the conductive layer (22). [30] Optical-electrical conductor system (100) according to claim 29, wherein at least one of the layers of the barrier layer (23) applied to the conductive layer (22) has a hardness of at least 800 HV, preferably at least 1200 HV, particularly preferably at least 2000 HV according to the test standard DIN EN ISO 14577-4:2007-8. [31] Optical-electrical conductor system (100) according to claim 29 or 30, wherein the barrier layer (23) comprises: - a layer applied to the conductive layer (22) with a nitride, in particular Si3N4, BN, AIN, TiN, AlSiN, SiON, SiAlON or an alloy of one of these substances, or with an oxide, in particular oxides of Si, Al, Ti, Zr, Zn, Sn, Ta, Nb, Y, TiO2, SiO2 or a ternary system of at least one of these substances, or with a carbide, boride, oxynitride, carbonitride, - or a sequence of such layers applied to the conductive layer (22). [32] Device (200) for detecting the immersion of an optical-electrical conductor arrangement (1) into a conductive medium (50), in particular within an animal or human body, comprising: an optical-electrical conductor system (100) according to one of claims 1 to 31, an evaluation unit (60) which is or can be electrically connected to the adapter sleeve (30) which is electrically conductive at least in some regions and to the conductive medium (50), and is configured to determine an impedance or impedance change between the adapter sleeve (30) and the medium (50) when the optical-electrical conductor arrangement (1) is or becomes immersed in the conductive medium (50), such that an immersion of the optical-electrical conductor arrangement (1) in the medium (50) can be detected and / or an immersion depth of the optical-electrical conductor arrangement (1) in the medium (50) can be determined. [33] Method for producing an optical-electrical conductor system (100), in particular according to one of claims 1 to 31, comprising: Providing or producing an adapter sleeve (30) which is at least partially electrically conductive, Providing or producing an optical-electrical conductor arrangement (1) comprising an optical waveguide (10) with an outer, organic cladding layer (13), and a conductive layer (22) applied directly or indirectly to the outer cladding layer (13) of the optical waveguide (10) as a coating, consisting of a single layer or a sequence of layers, Inserting the optical-electrical conductor arrangement (1) into the adapter sleeve (30) such that the adapter sleeve (30) mechanically grips the optical-electrical conductor arrangement (1) and electrically contacts its conductive layer (22), wherein the provided or manufactured adapter sleeve (30) has an electrically conductive contacting section (32) in order to electrically contact the conductive layer (22) of the optical-electrical conductor arrangement (1) and wherein an electrically conductive adhesive (41) is introduced into the contacting section (32) in order to electrically contact the conductive layer (22) of the optical-electrical conductor arrangement (1). [34] Method according to claim 33, wherein the provided or manufactured adapter sleeve (30) has a fixing section (31) to mechanically grip the optical-electrical conductor arrangement (1) and wherein an adhesive (40) is introduced into the fixing section (31) in order to additionally fix the optical-electrical conductor arrangement (1). [35] Method according to one of claims 33 or 34, wherein the production of the optical-electrical conductor arrangement (1) comprises: - providing an optical waveguide (10) with an outer cladding layer (13), - Coating the cladding layer (13) of the optical waveguide with a functional layer system (20), comprising: - creating a base layer region (21) consisting of a single layer or a sequence of layers, - Applying an electrically conductive layer (22) consisting of a single layer or a sequence of layers to the base layer area. [36] The method of claim 35, wherein generating the base layer region (21) comprises: - Pretreating the cladding layer (13) of the optical waveguide (10), in particular by means of chemical or physical processes to change the surface properties of the cladding layer (13) in order to produce a surface layer with at least one changed surface property, in particular to produce a surface layer with an increased surface energy and / or an increased number of oxygen radicals and / or to remove residues. [37] A method according to claim 35 or 36, wherein the generation of the base layer region (21) comprises: - Applying a layer or a sequence of layers to the outer cladding layer (13), in particular by means of cathode sputtering, high-frequency sputtering, reactive sputtering and / or magnetron sputtering. [38] Method according to one of claims 33 to 37, wherein the application of the conductive layer (22) is carried out by means of cathode sputtering, high-frequency sputtering, reactive sputtering and / or magnetron sputtering. [39] Method according to one of claims 36 to 39 when referring back to claim 36, wherein the coating of the cladding layer (13) with a functional layer system (20) further comprises: - Applying a barrier layer (23) consisting of a single layer or a sequence of layers on the conductive layer (22), in particular by means of cathode sputtering, high-frequency sputtering, reactive sputtering and / or magnetron sputtering. [40] Method according to one of claims 33 to 40, wherein the production and / or application of at least two layers takes place in a vacuum and without vacuum breakage. [41] Method according to one of claims 33 to 41, wherein the application of one or more layers is carried out with the addition of oxygen and argon, the ratio of oxygen to the total flow of oxygen and argon influencing the metallic or dielectric character of the respective layer.

Images