Sensor head for fluorescence spectroscopy

Abstract

The invention relates to a light transmitting component (10), in particular for a sensor head (60a) or for connection to a coupling light guide (27), for transmitting electromagnetic radiation, in particular through a wall (4), comprising a lead-through coupling element (15), which is configured for being arranged in a main body (12) or in a wall opening, for incoupling and transmitting the electromagnetic radiation through the lead-through coupling element, in particular through the wall (4), without divergence, wherein the lead-through coupling element (15) comprises a multi core fiber rod (MCR) or consists thereof and is designed with positional offset tolerance in such a way that a lateral positional offset between the lead-through coupling element (15) and a light transmitting component coupled thereto, such as a coupling light guide, of 10 µm or more, preferably 20 µm or more, more preferably 30 µm or more, results in a relative signal loss of 10% or less, preferably 7% or less, more preferably 5% or less, or even of 3% or less.

Description

[0001] Sensor head for fluorescence spectroscopy

[0002] Area of

[0003] The present invention relates to a light transmission component for coupling and transmitting electromagnetic radiation, the use of a light transmission component for monitoring or optically analyzing a fluid volume, a wall measuring system and a feedthrough coupling element.

[0004] Background and general description of the invention

[0005] The analysis and observation of fluids such as liquids hidden behind a wall is subject to constant development. On the one hand, existing biological, chemical, or physical reagents or samples should be further improved for analysis or observation; on the other hand, there are always new ideas, reagents, or samples that need to be made accessible for measurement. A wide variety of measurement methods are used to obtain a wide spectrum of information. At the applicant's company, the possibilities of optical measurement are particularly noteworthy, given the applicant's product portfolio and application expertise.Against this background, the present application deals with the improvement of the optical measurement of a fluid volume, such as a biological sample or a chemical mixture, wherein the measurement can advantageously be carried out without undesired influence on the fluid volume - unless an influence on the fluid volume is intended, which then also falls within the subject matter of this application.

[0006] The problem with the installation and use of optical measuring systems on or in a wall, such as that of a container or a pipe, is always the resistance to the fluids to be measured and the achievable tightness, as well as the achievable signal quality, which may also suffer from the fact that the system is typically designed to be resistant and tight against a leaking fluid.

[0007] One aspect of the invention solves the problem of increasing the signal strength or quality obtained for fluid volume measurements compared to known measuring devices. Another aspect of the invention solves the problem of avoiding or preventing fluid leakage. Yet another aspect of the invention solves the problem of introducing as little or no impairment as possible into the fluid volume to be measured by the measuring system.

[0008] The present description presents a light transmission component which is particularly suitable or configured for a sensor head or for connecting a coupling optical fiber. The light transmission component is provided for transmitting electromagnetic radiation. In other words, the light transmission component is designed or constructed such that electromagnetic radiation, for example light, a light pulse, or an optical signal, can be guided through the light transmission component. The light transmission component is preferably further configured such that the electromagnetic radiation can be guided through a wall. The light transmission component can be configured for the sensory detection of a property of a fluid arranged in a container or pipeline. For this purpose, the light transmission component can be in direct contact with the fluid in sections.

[0009] For this purpose, the light transmission component comprises a feedthrough coupling element, which is designed for arrangement in a base body or in a wall opening. In other words, the feedthrough coupling element is located in a base body or an opening in a pipe or container wall, so that it essentially fills the opening or even seals it independently. The feedthrough coupling element can, for example, be pressed into the opening, glazed in, in particular pressure-glazed in, or glued in. In other words, it is particularly advantageous if the opening is sealed in a fluid-tight manner by the light transmission component, in particular by the feedthrough coupling element. Depending on the application, the light transmission component can be designed to be gas-tight or sterile-tight.In a further application, the light transmission component can also be hermetically sealed, which can be determined, for example, using a helium leak rate test. It is also preferred if the light transmission component seals the wall opening in the container or pipe in a fluid-tight manner, or even in a gas-tight, sterile-tight, or hermetically sealed manner.

[0010] The feedthrough coupling element is particularly suitable for coupling in and passing through the electromagnetic radiation, thus it has, for example, one or more light-guiding bodies, in particular one or more glass bodies, in order to preferably guide the electromagnetic radiation such as light, an optical measuring signal or an optical pulse through the wall.

[0011] The feedthrough coupling element is preferably selected and configured such that electromagnetic radiation such as light is transmitted through it without divergence. Based on the concept of ray optics, divergence-free transmission of light or electromagnetic radiation is understood, in particular, to mean the transport of light without a distance-dependent increase in the beam cross-section, as in optical fibers such as glass fibers.

[0012] The feedthrough coupling element is preferably designed to be tolerant to positional misalignment. Positional misalignment tolerance is characterized by the fact that the signal loss due to inexact overlap or alignment between the feedthrough coupling element and an optical component coupled to it, such as a coupling fiber optic cable, is comparatively low, and in particular significantly lower than with known devices. For example, in certain applications, the positional misalignment tolerance may form the basis for enabling an optical measurement at this measuring point on the wall at all, since with previous methods, the received signal was so strongly attenuated that meaningful evaluation was impossible.The positional offset tolerance of the feedthrough coupling element is preferably designed such that a lateral positional offset between the feedthrough coupling element and a light-guiding component coupled thereto, such as a coupling light guide, of 10 pm or more, preferably 20 pm or more, more preferably 30 pm or more, results in a relative signal loss of 10% or less, preferably 7% or less, more preferably 5% or less, or even 3% or less. In other words, despite a positional offset that is significant by optical standards, for example 10% or more, preferably 20% or more, or even 30% or more of the diameter of the feedthrough coupling element, only a slightly impaired signal strength or an almost similarly large proportion of the electromagnetic radiation can be passed through the feedthrough coupling element. As compared to a perfectly centered coupling without positional offset.It can also be designed in such a way that with a positional offset of 100 pm or less, a predominant proportion of the electromagnetic radiation can still be transmitted, preferably of 80 pm or less, more preferably 60 pm or less. Furthermore, the feedthrough coupling element can be designed in such a way that the transmission losses or the signal loss for one of the aforementioned deviations lies in an interval which, in addition to the lower limit of the relative signal loss mentioned in the previous paragraph, has an upper limit of 0.5% or more of the original signal level, preferably 2% or more, or even 4% or more of the original signal level. The aforementioned tolerance values ​​can also be achieved if the signal path through the feedthrough coupling element is used in both directions. This is because with only one coupling direction orWith only one signal path, a larger diameter can be switched to at any coupling point according to the optical principle of "small to large." However, if both signal directions are required, the MCR is also advantageous in this respect.

[0013] A light transmission component, in particular for a sensor head or for connecting a coupling optical fiber, which can preferably comprise some or all of the above-mentioned elements and which is designed to transmit electromagnetic radiation, in particular through a wall, comprises, in a further embodiment that can be combined with the previously described embodiment, a feedthrough coupling element which is designed to be arranged in a base body or in a wall opening for coupling in and transmitting the electromagnetic radiation, in particular through the wall. The feedthrough coupling element is designed such that it has a numerical aperture for the electromagnetic radiation of 0.21 or greater, preferably 0.25 or greater, particularly preferably 0.3 or greater, further preferably 0.4 or greater. For example, the numerical aperture can be in a preferred range between 0.5 and 0.6.Alternatively or cumulatively, the feedthrough coupling element is designed to have a numerical aperture of 1.2 or less, or even 0.9 or less, preferably 0.8 or less.

[0014] A light transmission component, in particular for a sensor head or for connecting a coupling optical fiber, which can preferably comprise some or all of the aforementioned elements and which is designed to transmit electromagnetic radiation, in particular through a wall, comprises, in a further embodiment that can be combined with the previously described embodiment, a base body that can be inserted in a fluid-tight manner into a flange receptacle of the wall or that can be detachably connected thereto in a fluid-tight manner. The base body has a base body thickness in a direction perpendicular to the wall. If, for example, the base body thickness corresponds to the wall thickness and the base body were inserted flush into the wall, then the wall is flush with the base body on the inside and outside. If the base body thickness is greater than the wall thickness, then the base body projects inwards or outwards beyond the wall. A possiblyAny remaining overhang should preferably be less than 200 μm, particularly preferably less than 100 μm, further preferably less than 50 μm, and most preferably less than 10 μm. The most favorable arrangement, however, is a flush arrangement without any overhang. The base body thickness does not have to be homogeneous over the entire extent of the base body. It is particularly advantageous if the thickness of the base body in the area of ​​the opening or receptacle for the feedthrough coupling element corresponds to the base body thickness and is measured in particular there. If, for example, a flange connection is provided on the wall, for example comprising screw holes for screwing on the base body, then it can be advantageous to place the base body onto the flange connection from the outside, so that most or all of the base body thickness lies outside the wall.

[0015] The light transmission component of this design comprises the feedthrough coupling element, which is inserted into the base body. The feedthrough coupling element is located in a base body opening for coupling and transmitting the optical signal through the base body and thus through the wall. The feedthrough coupling element also has a coupling element length in the direction perpendicular to the wall and / or in the direction of the base body thickness. The base body thickness is identical to the coupling element length, so that the feedthrough coupling element inserted into the base body opening does not protrude beyond the base body thickness.

[0016] The light transmission component described in the previous embodiments can further comprise an optical coupling for connecting the feedthrough coupling element to a sensor, which is arranged in particular in the sensor head, wherein the sensor is arranged in particular outside a wall. In other words, the sensor is preferably arranged on the outside of the wall, possibly directly coupled to the feedthrough coupling element. The sensor can also be connected to a coupling optical fiber, which is connected at its further end to the feedthrough coupling element. It is also conceivable to arrange the sensor within the wall together with the feedthrough coupling element.

[0017] The light transmission component described in the previous embodiments, in particular the feedthrough coupling element, can further be configured to seal the opening in the base body, in the container wall, or in the pipe wall in a fluid-tight, gas-tight, sterile-tight, and / or hermetically sealed manner. The sensor can be configured to sensorically detect a property of a fluid volume. The fluid volume is arranged, for example, in a container. A fluid volume arranged in a container can be referred to as a static fluid volume, although this can also include the fluid volume being stirred or otherwise mixed, shaken, or influenced, since it is essentially stationary.The fluid volume can also be arranged in a pipeline and, in particular, be a moving or variable fluid volume; it can nevertheless be referred to as such even if the fluid volume is at rest in sections of the pipeline, is moved intermittently, or at varying speeds through the pipeline, because the result is a variable fluid volume. The wall in which the light transmission component is arranged can therefore, in the preferred case, be a container wall or a pipe wall.

[0018] The feedthrough coupling element has a refractive index. A coupling optical fiber coupled to the feedthrough coupling element also has a refractive index. The coupled coupling optical fiber can then have a different refractive index than the feedthrough coupling element, which can, for example, differ by 10% or more from that of the feedthrough coupling element. This results in a wide range of materials for the coupling optical fiber, for example, plastic, quartz, multimode fiber, single-mode fiber, or even a light guide rod.

[0019] An optical coupling can be arranged on the feedthrough coupling element, possibly even directly on the feedthrough coupling element. In one embodiment, a detector or sensor can be arranged directly on the optical coupling of the feedthrough coupling element.

[0020] In the light transmission component as described in the previous embodiments, if it has the base body, the base body can have a flange connection for flanging to a counter-flange connection arranged on the wall.

[0021] The light transmission component described in the previous embodiments can further comprise a transparent cover, which is preferably arranged at or, in the direction of the fluid, in front of a front end of the feedthrough coupling element. The transparent cover can be made of or comprise quartz glass or plastic, for example, glass, quartz, or sapphire. For example, the cover can protect the light transmission component or the feedthrough coupling element from corrosive media or chemical influences. A mechanical protective effect for the light transmission component or the feedthrough coupling element can also be achieved by means of the cover.

[0022] Furthermore, or alternatively, a converter element can be included, in particular as an organic or ceramic converter. For example, the converter element can be arranged on the end face facing the fluid volume, or in front of it in the direction of the fluid. The downstream optical elements, such as feedthrough coupling elements or coupling light guides, can then be optimized for monochromatic light. Alternatively or cumulatively, a first optical band A can be used for excitation radiation, and a second band B for detection radiation.

[0023] In a particular embodiment, the sensor can alternatively or additionally be equipped for contact, in particular direct contact, with the fluid volume. In this embodiment, the sensor is arranged at or in front of the front end of the feedthrough coupling element for transmitting an electromagnetic signal or pulse through the feedthrough coupling element.

[0024] The electromagnetic radiation can define an optical signal. The electromagnetic radiation can be passed from the feedthrough coupling element into a fluid volume or from the fluid volume into the feedthrough coupling element. Furthermore, the feedthrough coupling element can be configured to provide similar optical attenuation for both feedthrough directions, with the feedthrough coupling element being particularly bidirectional. Alternatively or additionally, the feedthrough coupling element can be configured to be broadband to allow the passage of electromagnetic radiation of different wavelengths.

[0025] If the light transmission component comprises an optical coupling, this can have one or more of the following properties: the optical coupling is detachably equipped, it is non-detachably equipped, it is clamped, it is screwed or crimped and / or it provides separability between the feedthrough coupling element and a coupling light guide connected thereto, and / or the optical coupling enables a detachable connection of the detector to the feedthrough coupling element.

[0026] The light transmission component as described in the previous embodiments can be equipped to withstand fluid pressure. Such fluid pressure can be applied to the light transmission component by the fluid volume arranged in the container or tube. In particular, the fluid pressure can be 3 bar or more, preferably 5 bar or more. The light transmission component ensures fluid tightness, in particular sterile tightness, gas tightness, or hermetic tightness.

[0027] The feedthrough coupling element can be designed to be positionally offset tolerant such that a lateral positional offset between the feedthrough coupling element and a light guide coupled thereto of 10 pm or more, preferably 20 pm or more, more preferably 30 pm or more results in a relative signal loss of 10% or less, preferably 7% or less, more preferably 5% or less, or even 3% or less.

[0028] The feedthrough coupling element can preferably comprise a flexible single fiber, a single core light guide rod (SCR) or a multi-core fiber rod (MCR). For example, an SCR or MCR can have a diameter of 100 pm or larger, or even 150 pm or larger, or even 200 pm or larger. In one variant, the feedthrough coupling element can consist of a flexible single fiber, an SCR or an MCR. The flexible single fiber or a single fiber of the MCR can, for example, have a thickness of 40 pm or less, preferably 30 pm or less, more preferably 25 pm or less. The specified thickness typically represents the diameter of the single fiber. The thickness can alternatively or cumulatively be 10 pm or larger, preferably 30 pm or larger, more preferably 50 pm or larger, or also preferably greater than 70 pm.

[0029] In one example, the diameter of the individual fiber of the MCR can have a favorable diameter ratio to the total diameter of the MCR. The diameter ratio between individual fiber and total diameter can be, for example, 1:10 or greater, preferably 1:8 ± 10%, or even 1:7 or smaller. For example, if the diameter of the MCR is 200 pm and the diameter of the individual fiber should preferably be smaller than 1 / 8 of the MCR diameter, then a particularly preferred diameter of the individual fibers can be in the range of 10 to 20 pm fiber diameter of the individual fiber. If the diameter of the individual fibers were selected in the range of 1:7 or greater, this can result in losses in the edge region during the transition from the multi-core system (MCR) to the coupling fiber (signal return path). The fewer individual fibers used in the MCR, the higher the percentage of edge fibers that only partially transmit.On the other hand, the number of fibers is limited, for example, by the fact that as the number of fibers increases, their size and thus also the cladding thickness decreases. If the cladding thickness of the individual fiber falls below a range of approximately 1 to 2 pm, this can lead to the light guidance of the individual fibers collapsing and significant additional losses occurring. In this case, it is advantageous to choose a diameter of the MCR large enough to compensate for all lateral tolerances as well as, for example, diameter tolerances. It is therefore advantageous if the MCR has a larger diameter than a coupling fiber to be coupled to it. For example, the diameter of the MCR can be 25% or more larger than the diameter of the coupling fiber, preferably 40% or more, more preferably 50% or more.For example, if a coupling fiber is to have a core diameter of 200 pm, the diameter of the active region of the MCR can be selected between 280 pm and typically 320 pm, or even larger if circumstances such as the installation situation allow. With an MCR diameter of 300 pm, a maximum offset tolerance of approximately 50 pm results, measured from a zero-offset overlap toward the edge, in all lateral directions. With an MCR diameter of 350 pm, a maximum offset tolerance of 75 pm results.

[0030] The SCR or MCR may have a core component. Such a core component may, for example, comprise optical glass. The core component may consist of a glass composite. Alternatively or cumulatively, the SCR or MCR may have a cladding component. For example, the cladding component may comprise cladding glass.

[0031] If the MCR contains the core component, there may be a difference in the coefficient of thermal expansion (ACTE) of the respective material used between the core and cladding. For example, this ACTE may be less than or equal to 1x10 A -6 1 / K, preferably 0.5x10 A -6 1 / K or less and particularly preferably 0.2x10 A -6 1 / K or less. If the ACTE between core and cladding is close to or equal to 0, meaning there is a similar or identical CTE between the materials used, this can again offer advantages in terms of thermal shock resistance.

[0032] Two example systems are presented below. The first example will be given the system title "F."

[0033] In system “F”, the core of the feedthrough coupling element can comprise a glass of composition PbO 40-50 wt%; SiO2 40-50 wt%; Na2O 1-10 wt%; K2O 1-10 wt%; and As2O3 less than 1 wt%.

[0034] The CTE of the core can be measured in the “F” system at 9.1 x10 A -6 1 / K.

[0035] In system "F," the jacket of the feedthrough coupling element can comprise a glass with the composition SiO2 55-76 wt%; Al2O3 0-5 wt%; B2O3 0-5 wt%; Li2O+Na2O+K2O together 5-25 wt%; MgO- ^aO+SrO+BaO+ZnO together 5-20 wt%; TiO2+ZrO2 together 0-5 wt%; P2O5 0-2 wt%. The GTE of the jacket can advantageously correspond to the GTE of the core, i.e., also in the range of 9.1 x 10 A -6 1 / K or exactly that value. The resulting numerical aperture can be in the range of 0.5 to 0.6, for example, 0.55 or 0.58.

[0036] In another system, "G," the core can have a glass composition of PbO 40-50 wt%; SiO2 40-50 wt%; Na2O 1-10 wt%; K2O 1-10 wt%; and As2O3 less than 1 wt%. The GTE of the core in system "G" can be set to 8.3x10 A -6 1 / K.

[0037] Alternatively, in system “G” the core may comprise a glass of composition SiO2 60-75 wt%, B2O3 10-15 wt%, Na2O 5-15 wt%, K2O 5-10 wt%, CaO 0.1-1 wt%, BaO 0.5-3 wt%, TiO2 of more than 0-1.7 wt%; and Sb2O3 0-0.5 wt%.

[0038] In system "G", the cladding composition can be as follows: SiO2 71-77 wt%, B2O3 9-12 wt%, Al2O3 3.5-6 wt%, Na2O 5.5-8 wt%, K2O 0-0.5 wt%, Li2O 0-0.3 wt%, CaO 0-3 wt%, BaO 0-1.5 wt%, F 0-0.3 wt%, Cl- 0-0.3 wt%, and MgO- ^aO+BaO+SrO together 0-2 wt%. The CTE of the cladding can be set to 4.9x10 A -6 1 / K. The numerical aperture can be in the range of NA = 0.25 to 0.3. For example, the NA can be 0.26 or 0.27.

[0039] In system "G," an additional shell can be provided around the cladding. The shell can have a composition of SiO2 55-76 wt%; Al2O3 0-5 wt%; B2O3 0-5 wt%; Li2O+Na2O+K2O together 5-25 wt%; MgO+NaO+SrO+BaO+ZnO together 5-20 wt%; TiO2+ZrO2 together 0-5 wt%; P2O5 0-2 wt%. The CTE of the shell can be set to 9.1x10 A -6 1 / K.

[0040] The addition of conventional refining agents is possible for all of the above-mentioned compositions.

[0041] The SCR or MCR typically has a numerical aperture (NA). The NA is preferably greater than 0.3, preferably greater than 0.4. For example, the NA can be set between 0.5 and 0.6. Alternatively or cumulatively, the NA of the SCR or MCR can be 0.9 or less, preferably 0.8 or less. In one embodiment, the NA can be 0.86.

[0042] The SCR or MCR can be equipped to resist acids. The SCR or MCR can have a chemical resistance class of 1 or 2 for acids, 1 or 2 for alkalis, and possibly 1 or 2 for water.

[0043] Preferably, the SCR or MCR can be pressed and / or bonded into the wall opening, i.e., for example, in a container or pipe flange. The bond can be heat-curing and / or UV-curing. Alternatively or additionally, the wall opening, i.e., for example, the container or pipe flange, can be shrunk onto the SCR or MCR. In another variant—which can be combined if necessary—the SCR or MCR can be hermetically sealed to the inside of the wall opening or directly to the container or pipe using a low-melting glass solder.

[0044] There may be a difference in the coefficient of thermal expansion (CTE) between the MCR and the surrounding body, such as the base body or the glazing, and in particular, an ACTE between the materials used. It has therefore been shown to be advantageous if the ACTE lies between 3 and 11 ppm / K. The CTE of the base body is greater than that of the MCR.

[0045] The MCR can have partially or partially fused fibers. Partial or partial melting of fibers can provide increased impermeability to fluid flow. For example, this can reduce the capillary action for the fluid, so that the fluid can no longer move along the individual fibers toward the container exterior due to the buildup of capillary forces. This thus increases the impermeability, for example, to sterile tightness or even fluid tightness. The impermeability can also be further improved by using or applying a cover glass. Accordingly, the MCR is particularly preferably designed to prevent capillary action for the fluid volume.

[0046] For example, melting can result in individual fibers in the outer region of the MCR's external fibers being partially or partially integral with one another. In other words, adjacent fibers form a partial or partial integral bond, in particular a molten bond, with one another. For example, previously round fibers can be converted into a hexagonal structure. The fibers are then subjected to a heat treatment and, if necessary, glazing, whereby the individual fibers are kept intact. This can be combined with pressure glazing, for example. A structural change to the individual fiber that goes into the depth of the individual fiber is typically not desired, as this can change the optical properties of the fiber to such an extent that the transmission of light is impaired or even prevented.A further advantage of using an MCR is that even if the optical properties of one or more edge layers are impaired by the joining process, the transmission behavior of the inner fibers is not affected. This means that the edge fibers provide a buffer or compensation layer, if sufficiently dimensioned, to prevent or mitigate damage caused by the joining process, for example. The MCR can also comprise a fiber plate, which is formed by fusing or melting a plurality of individual fibers together, thus forming a partially or partially interconnected plate.

[0047] The feedthrough coupling element usually has an end face facing the fluid volume. The end face is preferably flush with the wall or the base body. For example, a flush finish of the end face of the feedthrough coupling element can be achieved by removing or polishing the end face using an abrasive process. In other words, an original end face of the feedthrough coupling element can initially protrude beyond the wall or the base body, wherein in one embodiment the length of the feedthrough coupling element is greater than the thickness of the base body or the wall. Subsequently, the feedthrough coupling element already inserted into the base body or the wall opening can then be removed, for example polished, in order to reduce the length of the feedthrough coupling element to the surface of the base body or the wall.As already described, the front side can have a coating, in particular a seal, whereby the coating or seal can then be applied after the removal, for example the polishing.

[0048] The light transmission component described in the previous embodiments may further comprise an optical beam splitter arranged on an outer side. Such a beam splitter may be provided to separate the incoming light from the outgoing light. It may, in particular, be a polarizing beam splitter.

[0049] The light transmission component described in the previous embodiments can further comprise a support element, in particular adapted for arrangement on the feedthrough coupling element, on the base body, or on the wall. For example, the support element is arranged on the outside of the wall. The support element can be adapted or provided to support the feedthrough coupling element against shear forces, for example in the case where the feedthrough coupling element projects beyond the wall with its length, in particular projects outwards. Furthermore, the light transmission component can have a cooling device arranged on the outside of the light transmission component, in particular to efficiently dissipate heat generated by incoming radiation loss and, for example, to protect the feedthrough coupling element from damage or deformation.Such a cooling device can have cooling fins or provide liquid cooling.

[0050] The feedthrough coupling element can further comprise a conical widening to improve hermeticity, which is particularly oriented in the direction outside the wall or the container or pipe.

[0051] The feedthrough coupling element can comprise an imaging optic, which is inserted in particular in the wall opening together with the feedthrough coupling element.

[0052] The bushing coupling element can also be metallized around its periphery to create a direct metallic joint between the bushing coupling element and the wall opening. Stainless steels, such as austenitic or ferritic, can be used for this purpose. Inconel, molybdenum, or titanium can also be used.

[0053] A solder glass can also be arranged between the feedthrough coupling element, for example a light guide rod, and the container opening. In other words, solder glass can be inserted in the direction perpendicular to the wall between the feedthrough coupling element and an inner side of the opening to compensate for any manufacturing tolerances and / or to compensate for deviations in the shape of the feedthrough coupling element and / or the opening from a perfect fit, such as in particular a perfect circular shape, and / or to improve the optical quality. On the other hand, it can be preferred for the enveloping glass of the feedthrough coupling element to represent the interface to the inner side of the opening, in particular the metal of the wall.

[0054] The feedthrough coupling element can be inserted into the wall opening using pressure glazing. Glazing or pressure application can result in compaction of the fibers, primarily in the edge area of ​​the MCR.

[0055] With regard to the materials used for the feedthrough coupling element, it is advantageous if the materials or material combinations release little or no substances into the fluid. For example, a low nickel leech rate is advantageous if the observed fluid contains organic or living parts, substances, or materials in order to avoid any influence, particularly any harmful influence. The light transmission component as described in the previous embodiments can further comprise an index-adapting intermediate piece. The index-adapting intermediate piece can be arranged in the optical coupling and / or between the feedthrough coupling element and the coupling light guide coupled thereto. The index-adapting intermediate piece can comprise, for example, an immersion oil or gel.For example, the index-matching spacer can be bonded to the feedthrough coupling element or a coupling fiber with a refractive index-matched adhesive. An immersion element, such as an immersion pad or an optically transparent cushion, can also be used. Such an optically transparent cushion can also serve as a damping element for mechanical decoupling. The immersion element can also be provided with an index-matched, preferably permanently elastic, adhesive.

[0056] One aspect of the present description relates to the use of the light guide component for monitoring or optically analyzing a fluid volume, in particular liquids, in a container or pipe. The container or pipe can be made of or comprise aluminum, metal such as cast metal, stainless steel, or glass-fiber-reinforced plastic, in particular for storing chemical or pharmaceutical substances or foodstuffs. Such substances can also include petrochemical substances such as, in particular, gasoline, diesel, or kerosene. The container or pipe or supply line can then be a fuel tank or a fuel-carrying line. Possible fields of application include motor vehicles, ships, power generation, and aviation.

[0057] A further aspect of the present description relates to the use of the light-conducting component for monitoring or optically analyzing a fluid volume, in particular liquids, in disposable plastic containers, particularly for use in medical devices, for example in in-vitro diagnostic systems, such as a virus tester, such as a COVID tester in the current global situation. Another example of medical devices in this field can include the measurement of blood composition in dialysis machines. The fluid volume can comprise, for example, a liquid or a gel.

[0058] Yet another aspect of the present description relates to the use of the light guide component for interference-free event monitoring of a fluid volume and / or for transmitting an optical signal, such as in particular for image transmission from a fluid volume or for light guidance into the fluid volume.

[0059] In yet another aspect of the present description there is a wall measuring system comprising a light transmission component as defined in at least one of the previously described embodiments, and further comprising a detector device, in particular as a detector head.

[0060] In the following, the invention is explained in more detail using exemplary embodiments and with reference to the figures, wherein identical and similar elements are partly provided with the same reference numerals and the features of the various exemplary embodiments can be combined with one another.

[0061] They show:

[0062] Fig. 1 first embodiment of a system with a light transmission component,

[0063] Fig. 2 to 5 modifications of the embodiment shown in Fig. 1 in different

[0064] Functions or designs,

[0065] Fig. 6 and 7 further embodiment of a light transmission component with base body,

[0066] Fig. 8 schematic representation of a feedthrough coupling element as a multi core fiber element (MCR),

[0067] Fig. 9 Top view of an MCR,

[0068] Fig. 10 further plan view of another embodiment of an MCR,

[0069] Fig. 11 Microscope image of a pressed and compacted MCR,

[0070] Fig. 12 graphical representation of the relative signal level over a lateral offset,

[0071] Fig. 13 Representation of geometric coupling losses,

[0072] Fig. 14 Representation of edge fiber losses.

[0073] Detailed description of the invention

[0074] Referring to Fig. 1, a first embodiment of a system 1 is shown which is configured to irradiate electromagnetic radiation 24 into a container 5. For this purpose, an illumination device 32 is connected to the feedthrough coupling element 15 by means of a coupling light guide 28, so that the electromagnetic radiation 24 can be irradiated through the feedthrough coupling element 15 into the container 5 and in particular into the fluid volume 2. A signal response 22 from the fluid volume 2, such as a fluorescence response, can be coupled into the feedthrough coupling element 15, passed through the feedthrough coupling element 15 and, in this example, forwarded to a detector 30 by means of a coupling light guide 26.

[0075] The feedthrough coupling element 15 is inserted into the base body 12. The base body 12 is in turn connected to the container 5 at a flange receptacle 18 of the container wall 4 by means of fastening means 14. A protective cap 16 is arranged on the end face 152 of the feedthrough coupling element 15 to improve the resistance of the feedthrough coupling element 15, for example, against chemical or biological influences inherent in the fluid volume 2.

[0076] In this example, a beam splitter 20 is provided to couple the incident radiation 24 from the light guide 28 and the outgoing radiation 22 into the light guide 26, wherein both radiation components are coupled into a common coupling light guide 27 for forwarding to the feedthrough coupling element 15. This makes it possible to guide incident and outgoing radiation through only one feedthrough coupling element 15.

[0077] Fig. 2 shows, in a merely schematic and reduced form, a modification of the system shown in Fig. 1, wherein an event detection system 1 is depicted in which an optical event 25 or pulse occurring in a fluid volume 2 is coupled into the feedthrough coupling element 15 and forwarded as an outgoing pulse 22 via a coupling optical fiber 26 to the detector 30. In a further development, as shown in Fig. 3, the system 1 can also be configured such that the sensor head 30a is coupled directly to the feedthrough coupling element 15 without the need for an additional coupling optical fiber, which may further increase the achievable signal quality.

[0078] In yet another schematic modification of the system 1 presented in Fig. 1, Fig. 4 shows an imaging system, wherein optical image information 22a from a fluid volume 2 is coupled into the feedthrough coupling element 15 and transmitted to a detection system 30b, such as a camera. The feedthrough coupling element 15 has an optical element 17 on its side 152 facing the fluid volume 2 to improve the coupling of the image information 22a into the feedthrough coupling element 15. If necessary, the optical element 17 can also be configured to improve biological or chemical resistance to the properties of the fluid volume 2.

[0079] Fig. 5 shows a further schematic modification of the system 1 shown in Fig. 1, wherein a light source 32, such as in particular a laser system, couples a light signal 24, for example a laser pulse, into the coupling light guide 28 shown. The coupling light guide 28 is in turn connected to the feedthrough coupling element 15 so that the light signal 24 can be coupled there and passed through the wall 4. Within the container 5, an illumination target 25a, such as a photodiode, is arranged such that it can be illuminated by the light signal 24. For example, by introducing the light signal 24 into the container 5, a subsequent event dependent on the light signal 24 can be triggered or prepared, such as an independent measurement taking place within the container 5.

[0080] Referring to Fig. 6, a light transmission component 10 with a base body 12 is shown, wherein the feedthrough coupling element 15 and a receiving area 29 arranged thereon for receiving a coupling light guide (see, for example, Fig. 5 or 8) can be seen. A coupling light guide 26, 28 can, for example, be pressed or glued into the receiving area 29 or coupled in some other way, for example even screwed. The feedthrough coupling element 15 can be pressed into the base body 12, for example by utilizing the thermal expansion of the base material of the base body 12, for example stainless steel. The receiving area 29 assumes the task and technical function of a coupling for coupling a coupling light guide 26, 28 to the feedthrough coupling element 15.To improve handling and increase rigidity against damage that can act on the light transmission component 10 when forces are applied transversely, this embodiment is equipped with a support element 11, for example in the form of a standing collar 11 that partially encloses the feedthrough coupling element 15 and completely encloses the receiving area 29. The light transmission component 10 is flanged to a container wall 4 of a container or pipe 5.

[0081] Referring to Fig. 7, a further embodiment of a light transmission component 10 is shown, wherein in this embodiment, for example, a sensor head 30a can be attached directly to the base body 12 and optically connected to the feedthrough coupling element 15. Particularly with such optical connections by directly attaching or flanging the sensor head 30a directly to the far end 15b of the feedthrough coupling element 15, it has proven challenging within the scope of the invention of the present description to obtain a sufficient signal strength for the measurement signal from the feedthrough coupling element 15. However, even when coupling a coupling optical fiber 26, 28, this has sometimes been difficult. The present description shows various improvements and solutions for this.A further development and improvement could be found in a further embodiment within the scope of the present description, which is presented beginning with Fig. 8. Given is an optical element to be coupled, such as a sensor head 30a or, in the case shown in Fig. 8, a coupling light guide 26, which is to be coupled to the feedthrough coupling element 15. When aligning the optical element to be coupled, deviations regularly occur such that the full surface of the end face 15b cannot be brought into overlap with the optical element to be coupled. For example, there may be differences in the diameter between the optical element to be coupled and the feedthrough coupling element 15, or there may be lateral offset. The signal losses observed here are immense; for example, a 20% signal loss already occurs with a lateral offset of only 20 pm.

[0082] However, these signal losses are considerably lower in the embodiment shown in Fig. 8. In this form, the feedthrough coupling element 15 is designed as a multi-core fiber rod (MCR) with a plurality of individual fibers 154. A signal 25 can be coupled into a plurality of the individual fibers 154 of the feedthrough coupling element 15. The light 25 emitted from the fluid volume initially strikes all fibers of the MCR 15. The fibers 154 that are congruent with or overlap the coupling light guide 26 are used. The signal level is independent of the positioning of the MCR 15 or the coupling light guide 26. In the case of lateral displacement, only the individual fibers used change, but not the transmission path or the locations of the coupling and analysis.

[0083] The coupling optical fiber 26, which is significantly smaller in this embodiment, only overlaps with a portion of the plurality of individual fibers 154. Nevertheless, the resulting signal quality is surprisingly good, as there are no coupling losses, which could otherwise result in the loss of all or a significant portion of the signal. Thus, it is also harmless if the coupling optical fiber 26 is uncoupled and recoupled, possibly in a slightly offset position. As Fig. 9 illustrates, the signal 25 is only transmitted to the coupling optical fiber 26 via a portion of the plurality of individual fibers 154. Fig. 10 shows an MCR 15 in an illustration, wherein the plurality of individual fibers 154 are enclosed by a common outer sheath 156.

[0084] Referring to Fig. 11, a microscope image of an MCR 15 glass-pressed into a glass body 7 is shown, wherein a partially pentagonal and partially hexagonal deformation of the individual fibers 154 of the MCR 15 is visible. The densification of the fiber spacing and simultaneous deformation of the individual fibers 154 achieved by hot pressing leads to a significantly improved fluid tightness, since the capillary effect for guiding the fluid 2 between the individual fibers 154 of the MCR 15 is greatly reduced. In other words, the previously existing free spaces between the individual fibers 154 of the MCR 15 are greatly reduced, and the individual fibers 154 have approximated their shape towards the highest possible packing density. By adjusting the hot process parameters, the melting of the fiber outer regions and thus the packing density of the individual fibers 154 can be influenced.This can also influence the fluid tightness of the MCR 15 and thus of the light transmission component.

[0085] For example, a ratio of the individual fiber diameter to the core diameter - i.e. the diameter of the MCR 15 - can be set in the range of 1 / 8 or smaller. With a core diameter of the MCR 15 of 200 pm, an individual fiber diameter of each individual fiber 154 can be selected in the range of 10 to 20 or 25 pm in order to transmit the highest possible signal intensity. The central region of the MCR 15 - i.e. the region that reliably overlaps with the coupling light guide 26, 28, should be large enough to accommodate all lateral and diameter tolerances. For example, with a diameter of the coupling light guide 26, 28 (core region) of 200 pm, a diameter of the active region of the MCR of, for example, 280 pm to typically 320 pm can be selected in order to obtain an optimal signal ratio. With a diameter of 300 pm of the MCR 15 in this example, this corresponds to an offset tolerance of about 50 pm.With an MCR 15 diameter of 350 pm, this would correspond to an offset tolerance of approximately 100 pm.

[0086] Referring to Fig. 12, the intensity curve of the electromagnetic radiation passed through the feedthrough coupling element is shown for the case of a lateral offset between the feedthrough coupling element and a coupling optical fiber coupled to it. In the case of the single-core component as a feedthrough coupling element, graph 42 shows that the signal intensity decreases significantly even with a comparatively small lateral offset. For example, in graph 42 of an SCR, a lateral offset of 20 pm results in a signal loss of approximately 5%, while a lateral offset of 50 pm results in a signal loss of over 35%. In the case of the MCR, however, graph 44 shows that the signal loss remains low even with a larger lateral offset.For example, with a lateral offset of the MCR compared to the coupling fiber optic cable of 20 pm, the signal loss is in the range of only 2%, and with a lateral offset of 50 pm it is only 10% or less.

[0087] Fig. 13 shows coupling losses due to a lateral offset of two equally sized cores 15 arranged in contact with each other. This is a relative representation, i.e., the offset AX is related to the diameter D of the core 15 or cores. For an exemplary fiber diameter of 100 pm and an exemplary offset of 20 pm, this results in a relative offset of 0.2. With a relative offset of 0.2, an efficiency of 75%, i.e., a 25% loss, can be seen from Fig. 13.

[0088] Fig. 14 quantitatively illustrates geometry-related losses for the case where an MCR 15 is coupled to a round fiber 27. It is assumed that the fibers involved in the transmission are those that are enveloped or intersected by a circle with the fiber diameter. When the no longer ideally round surface transitions to the fiber core, part of the light from the edge fibers is lost. As an approximation, the efficiency of the edge layer fibers is assumed to be 50%, since the overlap is quasi-random. Based on these assumptions, the loss is calculated as half the share of the edge fibers in the total number of fibers and is therefore solely dependent on the number of fibers parameter. For example, with 200 individual cores of the feedthrough coupling element 15 in the coupling area, the loss due to the edge fibers can be approximately 11%.

[0089] 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, it is apparent that the features, regardless of whether they are disclosed in the description, the claims, the figures or otherwise, also individually define essential components of the invention, even if they are described together with other features. In all figures, the same reference numerals designate the same features, so that descriptions of features that may only be mentioned in one figure or at least not with regard to all figures, can also be transferred to those figures with regard to which the feature is not described in the description.

[0090] 1 system with light transmission component

[0091] 2 fluid volume

[0092] 4 Wall e.g. of a container or pipe

[0093] 5 containers

[0094] 7 Vitreous body

[0095] 10 Light transmission component

[0096] 11 Support element

[0097] 12 basic bodies

[0098] 14 flange connectors

[0099] 14a flange connector

[0100] 15 Feedthrough coupling element

[0101] 15b front side facing away from fluid

[0102] 152 front side

[0103] 154 single fiber of the feedthrough coupling element

[0104] 156 Sheathing of the bushing coupling element

[0105] 16 Cover, protective cap

[0106] 17 optical element

[0107] 18 flange

[0108] 20 beam splitters

[0109] 22 emitted radiation

[0110] 22a Image information

[0111] 24 incident radiation

[0112] 25 Radiation event or pulse

[0113] 25a object to be illuminated

[0114] 26 light guides

[0115] 27 coupling light guides

[0116] 28 light guides

[0117] 29 Fiber optic receptacle

[0118] 30 Detector or sensor

[0119] 30a Sensor head 30b Camera

[0120] 32 Radiation source

[0121] 42 Signal curve multicore

[0122] 44 Signal curve Single core 46 Signal curve Coupling efficiency

[0123] 48 Signal curve number of fibers

Claims

1. Light transmission component (10), in particular for a sensor head (60a) or for connecting a coupling optical fiber (27), for transmitting electromagnetic radiation, in particular through a wall (4), comprising: a feedthrough coupling element (15), which is configured for arrangement in a base body (12) or in a wall opening for coupling and divergence-free transmission of the electromagnetic radiation through the feedthrough coupling element, in particular through the wall (4), wherein the feedthrough coupling element (15) comprises or consists of a multi-core fiber (MCR) and is designed to be tolerant of positional misalignment such that a lateral positional misalignment between the feedthrough coupling element (15) and a coupled optical fiber component such as a coupling optical fiber of 10 pm or more, preferably 20 pm or more, more preferably 30 pm or more, results in a relative signal loss of 10% or less, preferably 7% or less.preferably 5% or less, or even 3% or less.

2. Light transmission component (10), in particular for a sensor head (60a) or for connecting a coupling light guide (27), preferably according to claim 1, for transmitting electromagnetic radiation, in particular through a wall (4), comprising: a feedthrough coupling element (15), which is arranged for arrangement in a base body (12) or in a wall opening for coupling in and divergence-free transmission of the electromagnetic radiation through the feedthrough coupling element (15), in particular through the wall (4), wherein the feedthrough coupling element (15) has a numerical aperture of 0.21 or larger, preferably 0.25 or larger, particularly preferably 0.3 or larger, more preferably 0.4 or larger.

3. Light transmission component (10), in particular for a sensor head (60a) or for connecting a coupling light guide (27), preferably according to one of claims 1 or 2 for transmitting electromagnetic radiation, in particular by means of a Wall (4), comprising: a base body (12) which can be inserted into a flange receptacle (18) of the wall (4) in a fluid-tight manner or which can be detachably connected to it in a fluid-tight manner, and which has a base body thickness in a direction perpendicular to the wall, a feedthrough coupling element (15) inserted into the base body, which comes to lie in a base body opening for coupling in and divergence-free transmission of the optical signal through the wall, wherein the feedthrough coupling element has a coupling element length in the direction perpendicular to the wall, and wherein the base body thickness is identical to the coupling element length, so that the feedthrough coupling element inserted into the base body opening does not protrude beyond the base body thickness.Light transmission component (10) according to one of the preceding claims, further comprising an optical coupling (29) for connecting the feedthrough coupling element (15) to a sensor (30), which is in particular arranged in the sensor head (30a), wherein the sensor is in particular arranged outside a wall (4), and / or wherein the base body (12) has a flange connection for flange mounting to a counter-flange connection arranged on the wall (4).Light transmission component (10) according to one of the preceding claims, further comprising a transparent cover (16), in particular comprising or made of quartz glass or plastic, for example of glass, quartz or sapphire, and / or comprising the transparent cover (16), wherein the transparent cover is inserted into the wall opening, and in particular is flush with the wall opening, and / or comprising the transparent cover (16), wherein the transparent cover is inserted into the wall opening by means of pressure glazing, and / or further comprising a converter element (17), in particular as an organic or. ceramic converter. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) is configured to transmit the electromagnetic radiation into a fluid volume or to introduce it from the fluid volume into the feedthrough coupling element, and / or wherein the feedthrough coupling element (15) is configured to provide similar optical attenuation for both feedthrough directions, wherein the feedthrough coupling element is in particular bidirectional, and / or wherein the feedthrough coupling element (15) is configured to transmit electromagnetic radiation of different wavelengths in a broadband manner.A light transmission component (10) according to any one of the preceding claims, particularly characterized in that it is equipped to withstand fluid pressure, in particular a fluid pressure of 3 bar or more, preferably 5 bar or more, and thereby ensure a tight seal, and / or wherein the feedthrough coupling element (15) is designed to seal the wall opening in a fluid-tight manner. A light transmission component (10) according to any one of claims 2 to 7, wherein the feedthrough coupling element (15) is designed to be tolerant of positional misalignment such that a lateral positional misalignment between the feedthrough coupling element and an optical fiber (27) coupled thereto of 10 pm or more, preferably 20 pm or more, more preferably 30 pm or more results in a relative signal loss of 10% or less, preferably 7% or less, more preferably 5% or less, or even 3% or less.Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) comprises a flexible single fiber, a single core light guide rod (SCR) or a multi core fiber rod (MCR). consists of.

10. Light transmission component (10) according to the preceding claim, wherein the flexible single fiber or a single fiber of the MCR has a thickness of 40 pm or less, preferably of 30 pm or less, more preferably of 25 pm or less.

11. Light transmission component (10) according to one of the two preceding claims, wherein the SCR or the MCR has a core component comprising, for example, optical glass, and wherein the core component consists in particular of a glass composite, and / or wherein the SCR or the MCR has a cladding component, for example with a cladding glass.

12. Light transmission component (10) according to one of claims 9 to 11, wherein the SCR or MCR has a numerical aperture (NA) which is greater than 0.3, preferably greater than 0.4, and / or an NA of 0.9 or less, preferably 0.8 or less and / or in the range between 0.5 and 0.

6.

13. Light transmission component (10) according to one of claims 9 to 12, wherein the SCR or MCR is pressed and / or bonded into the container or pipe flange or the flange is shrunk onto it or is tightly connected to the flange or directly to the container wall or pipe flange with a low melting glass solder.

14. Light transmission component (10) according to one of claims 9 to 13, wherein the MCR has partially or partially fused fibers, and / or wherein the MCR has a fiberboard, and / or wherein the MCR is arranged to prevent capillary action for the fluid volume.

15. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) has an end face (152) facing the fluid volume, wherein the end face is flush with the wall (4) or the base body (12), wherein, for example, the end face is abraded or polished by means of an abrasive process, and / or wherein the end face has a coating, in particular a sealant.

16. Light transmission component (10) according to one of the preceding claims, further comprising a support element (11), in particular configured for arrangement on the feedthrough coupling element (15), on the base body (12) or on the wall (4), in particular for supporting the feedthrough Coupling element against shear forces.

17. Light transmission component (10) according to one of the preceding claims, further comprising a cooling device arranged on the outside of the light transmission component.

18. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) has a conical widening to improve sealing, in particular oriented outwards.

19. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) comprises an imaging optic (17) which is used in particular in the wall opening together with the feedthrough coupling element.

20. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) is metallized on its circumference to create a direct metallic joining connection between Feedthrough coupling element and wall opening. Light transmission component (10) according to one of the preceding claims, wherein the feedthrough coupling element (15) is inserted into the wall opening by means of pressure glazing. Light transmission component (10) according to one of the preceding claims, further comprising an index-adjusting intermediate piece arranged in the optical coupling (29) or between the feedthrough coupling element (15) and a coupling optical fiber (27) coupled thereto. Light transmission component (10) according to one of the preceding claims, wherein, in the direction perpendicular to the wall (4), solder glass is inserted between the feedthrough coupling element (15) and an inner side of the opening to improve the optical quality. Use of the light transmission component (10) according to one of claims 1 to 23 for monitoring orOptical analysis of a fluid volume in a container (4, 5) or a pipe (4) made of aluminum, metal such as a cast metal, stainless steel, or glass fiber reinforced plastic for storing petrochemical, chemical, or pharmaceutical substances or foodstuffs. Use of the light transmission component (10) according to any one of claims 1 to 23 for monitoring or optical analysis of a fluid volume in disposable plastic containers (5), particularly for use in medical devices, for example, in in-vitro diagnostic systems. Use of the light transmission component (10) according to any one of claims 1 to 23 for interference-free event monitoring of a fluid volume and / or for transmitting an optical signal, such as, in particular, for image transmission from a fluid volume or for transmitting light into the fluid volume.

27. Wall measurement system (1) comprising a light transmission component (10) according to any one of claims 1 to 23, a detector device (30), in particular as a detector head (30a).

28. Feedthrough coupling element (15) for a light transmission component (10) according to any one of claims 1 to 23.

Images