OPTOELECTRICAL GUIDE/CONDUCTOR SYSTEM WITH ADAPTER SLEEVE

Abstract

An optoelectrical guide/conductor system is provided that includes an optoelectrical guide/conductor arrangement and an at least regionally electrically conductive adapter sleeve. The arrangement has an optical waveguide with an outer, organic sheath layer and a conductive layer. The conductive layer is a single layer or a sequence of layers, which is directly or indirectly on the outer sheath layer. The sleeve mechanically embraces the arrangement and electrically contacts the conductive layer such that the adapter sleeve is insertable into a connection mount, arranged e.g. on a handpiece, for transmitting optical and/or electrical signals through the conductive layer.

Claims

1. An optoelectrical guide/conductor system, comprising: an optoelectrical guide/conductor arrangement comprising an optical waveguide and a conductive layer, the optical waveguide having an outer, organic sheath layer, the conductive layer is a single layer or a sequence of layers, the conductive layer is directly or indirectly on the outer sheath layer; and an adapter sleeve that has a conductive region, the adapter sleeve mechanically embraces the optoelectrical guide/conductor arrangement with the conductive region in electrical contact with the conductive layer so as to transmit optical and/or electrical signals between the conductive layer and the conductive region.

2. The system of claim 1, wherein the adapter sleeve has an outer sleeve body enclosing an inner receiving opening along a sleeve axis, and wherein the optoelectrical guide/conductor arrangement extends along the sleeve axis through the inner receiving opening.

3. The system of claim 2, wherein the inner receiving opening is cylindrical and/or is arranged concentrically with respect to the outer sleeve body.

4. The system of claim 1, wherein the optoelectrical guide/conductor arrangement projects from the adapter sleeve on at least one side thereof and/or is embraced in the adapter sleeve in such a way that at least the optical waveguide is accessible from both sides of the adapter sleeve.

5. The system of claim 1, wherein the adapter sleeve has a fixing section that mechanically embraces the optoelectrical guide/conductor arrangement with a radial tolerance of less than 50 m and/or with a concentricity error of less than 50 m.

6. The system of claim 1, wherein the adapter sleeve is made of a material selected from a group consisting of metal, high-grade steel, nickel silver, conductive plastic, and conductive ceramic.

7. The system of claim 1, wherein the adapter sleeve has an ohmic resistance (R.sub.30) between 1 and 1000 milliohms, and/or wherein the conductive layer has an ohmic resistance (R.sub.22) between 1 and 1000 ohms.

8. The system of claim 1, wherein the conductive layer further comprises a barrier layer configured to inhibit diffusion of oxygen and/or ions of acidic or alkaline solutions into the conductive layer.

9. The system of claim 8, wherein the barrier layer has a hardness of at least 800 HV in accordance with the test standard DIN EN ISO 14577-4:2007-8.

10. The system of claim 8, wherein the barrier layer comprises a material selected from a group consisting of nitride, carbide, boride, oxynitride, carbonitride, Si.sub.3N.sub.4, BN, AN, TiN, AlSiN, SiON, SiAlON, oxide of Si, oxide of Al, oxide of Ti, oxide of Zr, oxide of Zn, oxide of Sn, oxide of Ta, oxide of Nb, oxide of Y, TiO.sub.2, SiO.sub.2, and alloys or ternary systems thereof.

11. The system of claim 1, further comprising an adhesive fixing the adapter sleeve and the optoelectrical guide/conductor arrangement to one another.

12. The system of claim 11, wherein the adhesive is an electrically conductive adhesive and is between the conductive layer and the conductive region.

13. The system of claim 12, further comprising a measurable impedance (Z) between the adapter sleeve and the optoelectrical guide/conductor arrangement, wherein the measurable impedance (Z) has a first portion from the conductive layer and a second portion from the conductive adhesive, wherein the second portion is less than or equal to 10 times the first portion.

14. The system of claim 13, wherein the second portion is less than or equal to 0.5 times the first portion.

15. The system of claim 13, wherein the first portion is dependent on a parameter selected from a group consisting of: an impedance of the conductive layer, an impedance of the conductive layer with respect to a medium surrounding the optoelectrical guide/conductor arrangement, and combinations thereof, and/or wherein the second portion is dependent on a parameter selected from a group consisting of: an ohmic resistance (R.sub.40) of the conductive adhesive, a capacitive reactance (C.sub.40) of the conductive adhesive, an ohmic resistance (R.sub.23/40) of a barrier layer configured to inhibit diffusion of oxygen and/or ions of acidic or alkaline solutions into the conductive layer, a capacitive reactance (C.sub.23/40) of the barrier layer, and any combinations thereof.

16. The system of claim 13, wherein the measurable impedance is measurable between an outer sleeve body of the adapter sleeve and an end region of the conductive layer projecting from the adapter sleeve.

17. The system of claim 1, wherein the optical waveguide comprises a core with a cladding that surrounds the core, the cladding is between the core and the outer sheath layer, and wherein the core has a refractive index that is greater than a refractive index of the outer sheath layer and/or is greater than a refractive index of the cladding.

18. The system of claim 1, wherein the outer sheath layer comprises a material selected from a group consisting of polyamide (PA), polyimide (PI), polymethyl methacrylate (PMMA), wax, waxlike constituents, and alkylsilane.

19. The system of claim 1, further comprising a functional layer system on the outer sheath layer, the functional layer system having a base layer region, wherein the conductive layer is on the base layer region.

20. The system of claim 17, wherein the base layer region comprises a material selected from a group consisting of an oxide, SiO.sub.2, TiO.sub.2, Al.sub.2O.sub.3, SnO.sub.2, HfO.sub.2, a boride, carbide, nitride, oxynitride, carbonitride, a metal, Si, Ti, Mo, and Cr.

21. The system of claim 1, wherein the conductive layer comprises a material selected from a group consisting of titanium, silicon, aluminum, gold, silver, molybdenum, tungsten or zirconium, and alloys thereof.

22. A device for detecting the immersion of an optoelectrical guide/conductor arrangement in a conductive medium, comprising: the optoelectrical guide/conductor system of claim 1; an evaluation unit electrically connected to the adapter sleeve and the conductive medium, wherein the evaluation unit is configured to determine an impedance or change in impedance between the adapter sleeve and the medium so that immersion of the optoelectrical guide/conductor arrangement in the medium is detected and/or an immersion depth of the optoelectrical guide/conductor arrangement in the medium is determined.

23. A method for producing an optoelectrical guide/conductor system, comprising: providing an adapter sleeve having a conductive region; providing an optical waveguide having an outer, organic sheath layer and a conductive layer with of a single layer or a sequence of layers, the conductive layer being applied directly or indirectly on the outer sheath layer; and inserting the optical waveguide into the adapter sleeve in such a way that the adapter sleeve mechanically embraces the optical waveguide with the conductive region and the conductive layer in electrical contact with one another so as to transmit optical and/or electrical signals between the conductive layer and the conductive region.

Description

DESCRIPTION OF THE DRAWINGS

[0080] Exemplary embodiments of the invention are described below with reference to the figures, in which:

[0081] FIG. 1 shows a cross section through an optoelectrical guide/conductor arrangement (1) having an optically guiding core (11), a cladding (12), a sheath layer (13) and a functional layer system (20);

[0082] FIG. 2 shows a cross section through an optoelectrical guide/conductor arrangement (1) having an optically guiding core (11), a sheath layer (13) and a functional layer system (20);

[0083] FIG. 3 shows a cross section through a device for detecting immersion (200) comprising an optoelectrical guide/conductor system (100) having an optoelectrical guide/conductor arrangement (1) and an adapter sleeve (30), which mechanically embraces the optoelectrical guide/conductor arrangement (1) and electrically contacts the conductive layer (22) thereof;

[0084] FIG. 4a shows an equivalent circuit diagram for the total impedance of an optoelectrical guide/conductor system (100); and

[0085] FIG. 4b: shows a simplified equivalent circuit diagram for the total impedance of an optoelectrical guide/conductor system (100).

DETAILED DESCRIPTION

[0086] FIG. 1 shows an optoelectrical guide/conductor arrangement 1 having an optical waveguide 10 with the diameter 10.1 thereof. The optical waveguide 10 has a core 11 composed of quartz glass and a cladding 12, here likewise composed of quartz glass. The refractive index n1 of the core 11 is greater than the refractive index n2 of the cladding 12. In addition and in particular as mechanical protection, a sheath layer 13 (buffer) embodied as a polymer layer/polymer sheath is provided. The sheath layer 13, as usual for optical waveguides of this type, comprises polyimide, PMMA or polyamide, or consists of at least one of these materials.

[0087] The optoelectrical guide/conductor arrangement 1 has on the sheath layer 13 a functional layer system 20, which in this example consists of a base layer region 21 embodied as an adhesion promoter layer directly on the sheath layer 13, a conductive layer 22 and an outer barrier layer (passivation layer) 23. The functional layer system 20 on the outer sheath layer 13 is producible by means of cathode sputtering or some other vacuum method (e.g. vapor deposition). In this case, the functional layer system 20 has a layer thickness 20.1.

[0088] FIG. 2 shows an optoelectrical guide/conductor arrangement 1 having an optical waveguide 10, wherein in this case the optical waveguide 10 has a core 11 and a sheath layer 13 directly surrounding the core 11. In this case, the refractive index n1 of the core 11 is slightly greater than the refractive index n2 of the sheath layer 13. The sheath layer 13 thus enables total internal reflection at the boundary layer with respect to the core 11 and hence light guiding. At the same time, the sheath layer 13 can serve as a mechanical protective layer.

[0089] The optoelectrical guide/conductor arrangement 1 furthermore has a functional layer system 20, which can be embodied and producible in the same way as in FIG. 1.

[0090] As already explained, the functional layer system 20 can comprise a plurality of individual layers. The latter here are a base layer region 21 embodied 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 optoelectrical guide/conductor arrangement, the entire layer sequence can be implemented in succession in a batch cycle without interrupting the vacuum process, with the result that a plurality of components having optoelectrical guide/conductor arrangements 1 of this type can also be coated in parallel in a cost-effective manner.

[0091] Further exemplary embodiments of the production of an optoelectrical guide/conductor arrangement are described below.

[0092] Example 1: optoelectrical guide/conductor arrangement 1 having an optical waveguide 10 embodied as a quartz fiber with a core 11 having a diameter of 150 m, a cladding 12 having a diameter of 180 m, and a sheath layer 13 embodied as a polymer layer and composed of polyimide with an outer diameter of the optical waveguide 10 of overall approximately 210 m.

[0093] A base layer region was produced by subjecting the sheath layer to a pretreatment. Ultrasonic cleaning using an alkaline or a neutral cleaning agent and IR drying was used in this case.

[0094] A conductive layer was applied consisting of a titanium coating having a thickness of 15 nm, which was produced by means of DC magnetron sputtering. The coating was effected in a vacuum at a process pressure of less than 1E-2 mbar. The sputtering target was chosen with a purity of 99%. The minimum distance between substrate and target was chosen to be 5 cm, the optical waveguide projecting into the plasma.

[0095] By means of a 4-point measuring instrument for determining the sheet resistance, a value of 10 ohms/sqr (wherein the unit ohm/sqr corresponds to the unit ohm) was measured. This corresponds to a resistivity of 1.5 E-5 ohm cm. The adhesion of the layer system was checked by means of an adhesion test according to DIN 58196-6 (1995 July). No detachments of the functional layer system from the optical waveguide were evident here.

[0096] Example 2: an optical waveguide embodied as a quartz fiber and having a sheath layer composed of polyimide was cleaned and preactivated by means of an atmospheric plasma in the form of a corona discharge. A coating was subsequently effected by means of reactive medium-frequency plasma of a silicon oxide coating, which was provided with a conductive molybdenum coating having a layer thickness of 24 nm without vacuum breach. This was followed by a passivation of this layer without vacuum breach by means of reactive magnetron sputtering with a silicon nitride coating having a layer thickness of 100 nm.

[0097] In a subsequent test of the sheet resistance, a sheet resistance of 5 ohms/sqr was determined by means of an inductive measurement method, an eddy current measuring instrument. No delaminations were able to be ascertained in accordance with the adhesion test mentioned above.

[0098] Example 3: an optical waveguide embodied as a quartz fiber and having a sheath layer composed of polyimide is cleaned by means of ultrasonic cleaning in accordance with example 1. The conductive layer applied directly to the sheath layer comprises molybdenum having a sheet resistance of 10 ohms/sqr. In order to protect the molybdenum coating, the coating of a barrier coating composed of TiO2 is optionally effected. Both coatings are produced in a magnetron sputtering process in a vacuum, wherein the optical waveguides project into the plasma and a virtually homogeneous coating is thus produced. The coatings are effected from a metallic sputtering target of purity 3N in the case of the molybdenum coating and, in the case of the TiO2 coating, from a metallic target or a partly ceramic target with the addition of oxygen. In this case, the TiO.sub.2 coating is embodied as partly amorphous and partly anatase. In a subsequent mechanical loading test that involves pulling aluminum test bodies having a mass of 22.5 g over the length of the optical waveguides, no scratches or delaminations of the metallic coating are evident on the basis of micrographs recorded by a light microscope with up to 100 magnification.

[0099] Example 4: in a further exemplary embodiment, an optical waveguide embodied as a quartz fiber and having a sheath layer composed of polyimide is pretreated by means of wet-chemical cleaning. This is followed by applying layers both of the base layer region and of the conductive layer with the addition of oxygen and argon. In order to ensure an improved adhesion between sheath layer and conductive layer, an adhesion promoter layer composed of TiO2 is formed therebetween, wherein, for producing the latter, the ratio of oxygen to the total flow of oxygen and argon is less than 0.4. Afterward, as a conductive coating, a metallic titanium coating having a sheet resistance of 1 ohm/sqr is coated, wherein, for producing the latter, the ratio of oxygen to the total flow of oxygen and argon is less than 0.1. As additional passivation, a further TiO2 coating is applied, wherein, for producing the latter, the ratio of oxygen to the total flow of oxygen and argon is less than 0.7.

[0100] The ratio of oxygen to the total flow (see exemplary ratios mentioned above) indicates how close the result is to the metal character or the dielectric character of the TiO2 layer.

[0101] FIG. 3 shows a device 200 for detecting the immersion of an optoelectrical guide/conductor arrangement 1 of an optoelectrical guide/conductor system 100 in a conductive medium 50. Such a device 200 thus corresponds to a preferred application of such an optoelectrical guide/conductor arrangement 1 for filling level determination 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 secured in an electrically conductive adapter sleeve 30 and together with the latter forms an optoelectrical guide/conductor system 100. In the exemplary embodiment shown, the adapter sleeve is connected to an electrical evaluation unit 60, which can couple AC voltage signals for impedance measurement with a specific frequency f into the sleeve. Furthermore, the evaluation unit 60 is conductively connected to the liquid 50 via ground or directly, as shown in FIG. 3.

[0102] The electrically conductive adapter sleeve 30, which can consist of high-grade steel or nickel silver, for example, has a fixing section 31 with the diameter 31.1 thereof and the length 31.2 thereof for receiving the optoelectrical guide/conductor arrangement 1. Furthermore, the adapter sleeve 30 can have a separate contacting section 32 with the diameter 32.1 thereof and the length 32.2 thereof. The diameters 31.1 and 32.1 and also the lengths 31.2 and 32.2 can differ in this case. Preferably, the fixing section 31 has a small diameter 31.1, which is only slightly greater than the diameter of the complete optical waveguide 10 with the functional layer system 20 thereof, such that upon adhesive bonding with an adhesive 40, it is possible to achieve a position afforded the closest possible tolerance, and with a small centricity error, in order that an optimum coupling of light into the optically guiding core 11 of the optical waveguide 10 (cf. FIG. 1 or 2) can be achieved. In general, laser light focused onto the core 11 is coupled in here. Special adhesives 40 of very low viscosity are often used for this purpose, which adhesives, on account of the capillary effect, can fill the adhesive gap thus produced.

[0103] With regard to an electrical coupling, however, it may be necessary additionally to provide a conductive adhesive 41 in the contacting section 32. This type of adhesive generally involves silver-filled epoxy adhesives, although these require a larger adhesive gap. Therefore, the diameter 32.1 of the contacting section 32 of the adapter sleeve 30 is greater than the diameter 31.1 of the fixing section 31 of the adapter sleeve 30.

[0104] The optoelectrical guide/conductor system, i.e. the optoelectrical guide/conductor arrangement 1 with the adapter sleeve 30 and the adhesives 40, 41 used, then form an impedance which is dependent on the frequency f and which changes upon contact with the liquid 50 or upon immersion in the latter. Here in the contacting of the optoelectrical guide/conductor arrangement 1 in the adapter sleeve 30, care should be taken to ensure the lowest possible contact impedances, both capacitively and owing to ohmic conduction, in order to enable a sufficiently sensitive detection of the filling level of the liquid or the immersion depth 22.3.

[0105] If this arrangement is considered at typical frequencies in the range of a few hundred hertz to approximately 100 kHz, inductive impedances can be disregarded, thus resulting in an electrical equivalent circuit diagram composed substantially of ohmic resistances and capacitors yielding the frequency-dependent total impedance Z.

[0106] Thus, to an approximation it is possible to outline schematically an equivalent circuit diagram as illustrated in FIG. 4a. Here, R.sub.30 is the ohmic resistance of the sleeve 30 (comparatively low resistance, in the m range).

[0107] R.sub.40 is the ohmic resistance of the adhesive gap for the adhesive 40 between optical waveguide 10 and functional layer system 20, depending on the adhesive layer thickness 40.1 d.sub.K40Q and the adhesive gap length 40.2 l.sub.K40Q and also the resistivity .sub.K40 of the adhesive 40 (the latter has a comparatively high value).

[0108] C.sub.40 is the capacitance of the adhesive gap with the adhesive 40, depending on the adhesive layer thickness 40.1 d.sub.K40Q, the adhesive gap length 40.2 l.sub.K40Q and the total diameter d.sub.Fg of the optical waveguide 10 including the functional layer system 20 d.sub.Fg and also the relative permittivity .sub.K40 of the adhesive 40.

[0109] R.sub.41 is the ohmic resistance of the adhesive gap for the conductive adhesive 41 between optical waveguide 10 and functional layer system 20, depending on the adhesive layer thickness 41.1 d.sub.K41Q and the adhesive gap length 41.2 l.sub.K41Q and also the resistivity .sub.K41 of the conductive adhesive 41 (the latter has a comparatively low value).

[0110] C.sub.41 is the capacitance of the adhesive gap with the conductive adhesive 41, depending on the conductive adhesive layer thickness 41.1 d.sub.K41Q and the adhesive gap length 40.2 l.sub.K41Q and also the relative permittivity .sub.K41 of the conductive adhesive 41.

[0111] R.sub.23/40 is the ohmic resistance of the barrier layer 23 of the functional layer system 20 in the region of the adhesive bonding with the adhesive 40, depending on its barrier layer thickness 23.1 d.sub.23 and the adhesive gap length 40.2 l.sub.K40Q and also the resistivity of the barrier layer 23 .sub.23 (generally very high value).

[0112] C.sub.23/40 is the capacitance of the barrier layer 23 of the functional layer system 20 in the region of the adhesive bonding with the adhesive 40, depending on its barrier layer thickness 23.1 d.sub.23 and the adhesive gap length 40.2 l.sub.K40Q and also the relative permittivity .sub.23 of the barrier layer 23.

[0113] R.sub.23/41 is the ohmic resistance of the barrier layer 23 of the functional layer system 20 in the region of the adhesive bonding with the conductive adhesive 41, depending on its barrier layer thickness 23.1 d.sub.23 and the adhesive gap length 41.2 l.sub.K41Q and also the resistivity of the barrier layer 23 .sub.23 (generally very high value).

[0114] C.sub.23/41 is the capacitance of the barrier layer 23 of the functional layer system 20 in the region of the adhesive bonding with the conductive adhesive 41, depending on its barrier layer thickness 23.1 d.sub.23 and the adhesive gap length 41.2 l.sub.K40Q and also the relative permittivity .sub.23 of the barrier layer 23.

[0115] R.sub.22 is the ohmic resistance of the conductive layer 22, depending on the conductive layer thickness d.sub.22 and conductive layer length 22.2 I.sub.22 and also the resistivity of the conductive layer 22 .sub.22, which has a comparatively low value.

[0116] R.sub.23(E) is the ohmic resistance of the barrier layer 23 depending on immersion depth 22.3 E and the barrier layer thickness 23.1 d.sub.23 and the resistivity of the barrier layer 23 .sub.23.

[0117] C.sub.23(E) is the capacitance of the barrier layer 23 of the functional layer system 20 in the region of immersion, depending on its barrier layer thickness 23.1 d.sub.23 and the immersion depth 22.3 E and also the relative permittivity .sub.23 of the barrier layer 23.

[0118] This equivalent circuit diagram in FIG. 4a can be simplified insofar as the ohmic resistance R.sub.30 of the adapter sleeve 30 is virtually negligible since it is in the m range. Furthermore, the ohmic resistance of the adhesive gap R.sub.40 for the adhesive 40 has a comparatively high value and thus contributes only very little to the total impedance. This also applies to the ohmic resistance R.sub.23/40 of the barrier layer 23 in the region of the adhesive 40. The same also applies to the ohmic resistance R.sub.23/41 of the barrier layer 23 in the region of the conductive adhesive 41. On the other hand, it is possible to disregard the capacitive portion of the adhesive gap C.sub.41 with the conductive adhesive 41 in relation to R.sub.41. It is likewise possible to disregard the ohmic resistance R.sub.23(E) of the barrier layer 23 depending on the immersion depth 22.3 E since this portion contributes very little to the conductivity on account of the high resistance of the barrier layer 23. This yields the simplified equivalent circuit diagram in FIG. 4b for the total impedance Z.

[0119] The individual impedances from the simplified equivalent circuit diagram in FIG. 4b are calculated here as follows:

C.sub.40.sub.0.sub.K40d.sub.Fgl.sub.K40Q/d.sub.K40Q(1)

C.sub.23/40=.sub.0.sub.23(d.sub.F+2d.sub.L)l.sub.K40Q/d.sub.23(2)

where d.sub.F is equal to the diameter 10.1 of the optical waveguide 10 including the conductive layer thickness 22.1 d.sub.L of the functional layer system 20 and the barrier layer thickness 23.1 d.sub.23

R.sub.41=.sub.K41d.sub.K41Q/(l.sub.K41Qd.sub.Fg)(3)

C.sub.23/41=.sub.0.sub.23(d.sub.F+2d.sub.L)l.sub.K41Q/d.sub.23(4)

R.sub.22=.sub.224l.sub.F/(((d.sub.F+2d.sub.22).sup.2d.sub.F.sup.2))(5)

C.sub.23(E)=.sub.0.sub.23d.sub.FgE/d.sub.23(6)

[0120] In accordance with one exemplary embodiment, for a functional layer system 20 having a conductive layer 22 composed of titanium (Ti) and a barrier layer 23 composed of TiO.sub.2, the following individual impedances result taking into account the following geometries, material constants and frequencies f:

[0121] first frequency f.sub.1: 1.000 l/s

[0122] second frequency f.sub.2: 10.000 1/s

[0123] diameter 10.1 of optical waveguide 10: 265 m=2.65 E-4 m

[0124] conductive layer thickness 22.1 of the Ti conductive layer: 0.4 m=0.4 E-6 m

[0125] barrier layer thickness 23.1 of TiO.sub.2: 100 nm=0.1 E-6 m

[0126] adhesive layer thickness 40.1 of the adhesive 40: 20 m=2 E-5 m

[0127] adhesive gap length 40.2 for the adhesive 40: 0.8 mm=8 E-4 m

[0128] adhesive layer thickness 41.1 of the conductive adhesive 41: 0.1 mm=1 E-4 m

[0129] adhesive gap length 41.2 for the conductive adhesive 41: 1.5 mm=1.5 E-3 m

[0130] conductive layer length 22.2: 50 mm=5 E-2 m

[0131] .sub.0: 8.85 E-12 As/Vm

[0132] .sub.23: 180

[0133] .sub.40: 10

[0134] .sub.22: 4.0 E-7 ohm m

[0135] .sub.41: 1.0 E-6 ohm m

[0136] first immersion depth 22.3 E: 0 mm

[0137] (fiber end just touches the liquid 50)

[0138] second immersion depth 22.3 E: 10 mm=1 E-2 m

[0139] third immersion depth 22.3 E: 20 mm=2 E-2 m

[0140] C.sub.40=3.0 pF

[0141] C.sub.23/40=11 nF

[0142] R.sub.41=0.08 m

[0143] C.sub.23/41=20 nF

[0144] R.sub.22=60

[0145] C.sub.23(E=0)=0 F

[0146] Given an immersion depth E=10 mm=1 E-2 m:

[0147] C.sub.23(E=10)=0.13 F

[0148] Given an immersion depth E=20 mm=2 E-2 m:

[0149] C.sub.23(E=20)=0.27 F

[0150] The following frequency-dependent absolute individual impedances thus result, with XC.sub.i representing capacitive reactive-power reactances and ZR.sub.i representing real ohmic resistances, where

XC.sub.i=1/C.sub.i=1/(2fC.sub.i)(7)

ZR.sub.i=R.sub.i(8)

[0151] The following values result for the first frequency f.sub.1=1 kHz:

[0152] X.sub.C40=54 M

[0153] XC.sub.23/40=15 k

[0154] ZR.sub.41=0.08 m

[0155] XC.sub.23/41=8 k

[0156] ZR.sub.22=60

[0157] XC.sub.23(E=0 mm) extremely high value

[0158] XC.sub.23(E=10 mm) 1.2 k

[0159] XC.sub.23(E=20 mm) 600

[0160] The following values result for the second frequency f.sub.2=10 kHz:

[0161] XC.sub.40=5.4 M

[0162] XC.sub.23/40=1.5 k

[0163] ZR.sub.41=0.08 m

[0164] XC.sub.23/41=800

[0165] ZR.sub.22=60

[0166] XC.sub.23(E=0 mm) extremely high value

[0167] XC.sub.23(E=10 mm) 120

[0168] XC.sub.23(E=20 mm) 60

[0169] The exemplary values show that with an appropriate choice of frequency and use of a conductive adhesive 41 in the contacting section 32, very good impedance relations occur, such that a filling level detection or measurement of the penetration depth 22.3 E is possible with comparatively simple electronic outlay within the evaluation unit 60.

[0170] In the case where the optoelectrical guide/conductor system 100 does not comprise a barrier layer 23, acting in particular as an insulator, in particular only contact resistances are still of significance. In such a case, for example, but in principle also independently thereof, DC voltage signal input couplings can also be used.

[0171] It is evident to the person skilled in the art that the embodiments described above should be understood to be by way of example and the invention is not restricted thereto, but rather can be varied in diverse ways, without departing from the scope of protection of the claims. Moreover, the features of the optoelectrical guide/conductor arrangement are also disclosed, mutatis mutandis, as features for the method for producing an optoelectrical guide/conductor arrangement, and vice versa. Features, irrespective of whether they are disclosed in the description, the claims, the figures or elsewhere, also individually define constituent parts of the invention, even if they are described jointly together with other features.

LIST OF REFERENCE SIGNS

[0172] 100 Optoelectrical guide/conductor system [0173] 1 Optoelectrical guide/conductor arrangement [0174] 10 Optical waveguide [0175] 10.1 Diameter [0176] 11 Optically guiding core [0177] 12 Cladding [0178] 13 Organic sheath layer [0179] 20 Functional layer system [0180] 20.1 Layer thickness [0181] 21 Base layer region [0182] 22 Conductive layer [0183] 22.1 Conductive layer thickness [0184] 22.2 Conductive layer length [0185] 22.3 Immersion depth [0186] 23 Barrier layer [0187] 23.1 Barrier layer thickness [0188] 30 Adapter sleeve [0189] 31 Fixing section [0190] 31.1 Diameter [0191] 31.2 Length [0192] 32 Contacting section [0193] 32.1 Diameter [0194] 32.2 Length [0195] 40 Adhesive [0196] 40.1 Adhesive layer thickness [0197] 40.2 Adhesive gap length [0198] 41 Conductive adhesive [0199] 41.1 Conductive adhesive layer thickness [0200] 41.2 Adhesive gap length [0201] 50 Liquid [0202] 60 Evaluation unit [0203] 200 Device for detecting immersion