Optical probe, and method for producing same

Abstract

The invention relates to an optical probe (1) designed to be optically coupled to at least one micro-optical component (50), and to a method for producing same; wherein the optical probe (1) comprises: - a probe head (10); - at least one micro-optical element (20), which is mechanically connected to the probe head (10) and is designed to establish an optical coupling to the at least one micro-optical component (50); and - at least one sensor structure (21), which is separate from the at least one micro-optical element (20) and is designed to generate a sensor signal (40) that indicates positioning of the probe head (10) relative to an object (100), wherein the at least one micro-optical element (20) and / or the at least one sensor structure (21) comprise / comprises at least one photocuring material.

Description

[0001] Optical probe and method for its manufacture

[0002] Field of the invention

[0003] The present invention lies in the field of optical coupling between optical components and relates to an optical probe configured for optical coupling to at least one micro-optical component, and a method for its manufacture. The optical probe can be used in particular in the manufacture, calibration, and testing of micro-optical components, particularly in communications engineering, sensor technology, medical sensor technology, and diagnostics; however, application of the optical probe in other fields is possible.

[0004] State of the art

[0005] Optical probes designed for optical coupling to at least one micro-optical component and methods for their manufacture are known from the prior art. In automated tests of micro-optical components, which may be present individually, assembled, or as an array in a wafer, a probe head is often optically coupled to at least one micro-optical component in order to be able to make statements about the functionality of the at least one micro-optical component. In this case, the optical coupling of a plurality of optical coupling points often has to be performed with a single probe head or two separate test heads. The optical coupling points can be distributed within a micro-optical component or across a plurality of micro-optical components.The micro-optical components are often part of a wafer and are frequently not yet isolated, as measuring micro-optical components that are part of a wafer is more efficient, faster, and cheaper. An optical facet is therefore often only accessible through a deep etch, which typically has a depth in the range of 25 pm to 100 pm and a width of typically 50 pm to 500 pm. Micro-optical elements that have deflection mirrors are therefore often required for optical coupling, as otherwise the optical coupling points are geometrically inaccessible. M Trappen, M Blaicher, PI Dietrich, T Hoose, Y Xu, MR Billah, W Freude, C Koos, 3D-printed optics for wafer-scale probing, 2018 European Conference on Optical Communication (ECOC), 2018, describes printed 3D micro-optics made from a combination of deflection mirrors and lenses that are suitable for measurement within deep etchings.However, the structures shown can easily be damaged by unintentionally present structures on a wafer or by incorrect operation.

[0006] Li et al., Ultrathin monolithic 3D printed optical coherence tomography endoscopy for pre-clinical and clinical use, Light: Science & Applications (2020) 9: 124, describes a device by which endoscopic measurements can be performed in organic tissue for medical purposes. A 3D-printed mirror rotates within a glass cannula with a diameter of 457 pm. The device generates a mode field diameter with a half-width of 12.4 pm, which corresponds to a mode field diameter of 21.8 pm at 1 / e 2Intensity. Furthermore, the cannula is at least 1 mm long in the Z direction, meaning it does not fit into an etching trench that is often less than 100 pm deep. Furthermore, the diameter of the cannula, at 457 pm, is so large that it does not fit into an etching trench typically between 50 pm and 250 pm wide. These dimensions cannot be significantly reduced, as the glass cannula requires a finite wall thickness and, at the same time, must accommodate a single fiber with a diameter of 125 pm. Furthermore, it is not acceptable for industrial manufacturing processes to insert fibers into cannulas, as this can easily damage micro-optical components. Furthermore, lithography on a single fiber is very complex.

[0007] US Pat. No. 7,183,759 B1 discloses a probe head for optical coupling via grating couplers to micro-optical components on a wafer surface. However, grating couplers are known to reduce the optical performance of micro-optical components because they can undesirably couple out light during operation. However, the capacitive sensor disclosed therein is not capable of detecting small objects, typically 1 pm to 500 pm in size. Furthermore, the capacitive sensor is heavy and expensive, and aligning the capacitive sensor with respect to a probe is complex.

[0008] US 2022 / 0163583A1 discloses an optical probe configured for optical coupling to at least one micro-optical component. The optical probe comprises a probe head and at least one micro-optical element having a mechanical connection to the probe head, which element is configured both to establish an optical coupling to the at least one micro-optical component and to generate a sensor signal indicating a positioning of the probe head relative to an object. DE 10 2017 221 952 B3 discloses a micro-optomechanical system and a method for its manufacture.The micro-optomechanical system comprises - at least one optical subsystem which is configured to emit at least one optical actuator signal and to receive at least one optical sensor signal; and - at least one optomechanical structure which can be produced by means of a direct microstructuring process in direct contact with the optical subsystem, wherein the optical subsystem comprises at least one optical actuator element and at least one optical sensor element, wherein the optical actuator signal, in interaction with the optical actuator element, is configured to change a mechanical state of the optomechanical structure, and wherein the optical sensor signal, in interaction with the optical sensor element, is configured to detect the change in the mechanical state of the optomechanical structure or a variable related thereto.

[0009] DE 602 03 037 T2 and EP 1 329 752 A1 disclose an end piece for an optical waveguide. In a particular embodiment, an arrangement can be used that includes a sensor for detecting a clear alignment between the optical waveguide and the optical path.

[0010] Object of the invention

[0011] Based on this, the object of the present invention is to provide an optical probe and a method for producing the optical probe, which at least partially overcome the disadvantages and limitations of the prior art.

[0012] As mentioned above, when coupling the at least one probe head to the optical coupling points, it is often necessary to move the at least one probe head within the deep etching, to guide it into or out of the deep etching, and to move it outside the deep etching. Contact or collision of the micro-optical elements with an object, in particular at least one wall of the deep etching or at least one other component, including a part of the wafer or dirt, etching residues, or resist residues inadvertently present on the wafer, should be avoided. In particular, it should also be possible to detect movement of the at least one probe head in at least a partial area above the wafer, since this area is critical for a collision.In particular, it should be ensured that damage to the micro-optical elements due to incorrect programming of the movement or incorrect manual movement of the at least one probe head, which could lead to a collision, is avoided. In particular, it should be ensured as reliably as possible that the performance of the at least one probe head and the micro-optical elements does not change during a measurement in a manner relevant to the measurement. Furthermore, a large number of measurements, preferably at least 1000, should typically be performed simultaneously at a large number of optical coupling points on a large number of micro-optical components, preferably at least 1000.

[0013] Furthermore, it should be possible to bring the micro-optical elements close to at least one micro-optical component or one of its optical coupling points to within a few micrometers, in particular 1 pm to 100 pm, without contact or collision of the at least one micro-optical component with the at least one optical coupling point or the optical facet occurring.

[0014] Furthermore, it should be possible to use the optical probe to detect objects with a size of 1 pm to 500 pm and protect the at least one micro-optical element from collision with the wafer. It would be desirable if the optical probe could achieve a detection accuracy of better than 100 pm, preferably better than 50 pm, and most preferably better than 10 pm.

[0015] Furthermore, it should be possible for the at least one micro-optical element to efficiently and reproducibly couple light between the probe head and the at least one micro-optical component. It would be desirable if the at least one micro-optical element could generate a focus with a mode fine diameter of twice the wavelength (e.g., 3 pm at 1500 nm) or less, particularly at a wavelength of 250 nm to 4000 nm, preferably at 1250 nm to 1650 nm.

[0016] Furthermore, structures that have optical functionality should not come into contact with the wafer or an optical component, as otherwise they can easily be damaged or confusion about the state of the structures with optical functionality can arise.

[0017] Furthermore, it should be possible to align the optical probe with respect to the micro-optical component in at least one dimension, preferably in three spatial dimensions, most preferably in all six translational degrees of freedom. An alignment accuracy of preferably 50 pm, particularly preferably 25 pm, in particular 10 gm, should be achievable.

[0018] The optical probe should be as lightweight as possible, especially to enable rapid measurement routines. The optical probe should be capable of being manufactured using an automated and reproducible manufacturing process.

[0019] Disclosure of the invention

[0020] This object is achieved by an optical probe and a method for its production having the features of the independent patent claims. Advantageous further developments, which can be implemented individually or in any combination, are presented in the following description and in the dependent claims.

[0021] In a first aspect, the present invention relates to an optical probe configured for optical coupling to at least one micro-optical component. The present optical probe comprises at least:

[0022] - a probe head;

[0023] - at least one micro-optical element having a mechanical connection to the probe head and configured to establish an optical coupling to the at least one micro-optical component; and

[0024] - at least one sensor structure separate from the at least one micro-optical element, which is configured to generate a sensor signal indicating a positioning of the probe head relative to an object.

[0025] The term “optical” refers here to a wavelength in the electromagnetic spectrum, which comprises a wavelength range from 1 nm to 1000 pm, ie both the visible spectral range from 380 nm to 760 nm, the adjacent ultraviolet spectral range from 1 nm to below 380 nm, as well as the likewise adjacent infrared spectral range above 760 nm to 1000 pm; preferably from 250 nm to 5 pm; particularly preferably from 350 nm to 4 pm; in particular from 530 nm to 1650 nm.

[0026] The term “optical probe” refers to a device that is configured for optical coupling to at least one optical component, preferably to at least one micro-optical component. The term “optical coupling” refers to the transmission of an optical wavelength, also referred to as “light,” between two optical components. When using the present optical probe, light can be transmitted from the probe head to the at least one micro-optical component and / or from the at least one micro-optical component to the probe head. The transmission of light from the probe head to the at least one micro-optical component or from the at least one micro-optical component to the probe head can occur sequentially or simultaneously.

[0027] The term "micro-optical component" refers to a micro-optical element that, during its intended use, processes light—in particular, conducts, generates, receives, modifies, reflects, amplifies, and / or interferes with it. Typically, the micro-optical component is an optical element to be investigated, i.e., one that has properties to be researched or controlled, that is being tested, or that can be temporarily operated. Within the scope of the present invention, a photonic integrated circuit (PIC), which can be arranged, in particular, on a wafer, can preferably serve as the micro-optical component.

[0028] In a particularly preferred embodiment, the micro-optical component can comprise at least one optical waveguide. The term "optical waveguide" refers to a micro-optical structure designed to restrict light transversely to its propagation direction, preferably such that only a single transverse mode can be formed for each polarization direction transversely to the propagation direction. In further, particularly preferred embodiments, the micro-optical component can comprise at least one laser, at least one modulator, at least one detector, or at least one optical amplifier, which can in particular be part of a photonic integrated circuit. However, the use of a different micro-optical component is possible.

[0029] As already mentioned, the present optical probe comprises at least one micro-optical element designed to establish the optical coupling desired according to the invention to the at least one micro-optical component. The term "micro-optical element" herein refers to an optical component designed to enable a transmission of light from the probe head to the at least one micro-optical component or from the at least one micro-optical component to the probe head, either sequentially or simultaneously. Herein, the term "micro-optical" refers to a structure having an extension of at most 1 mm, preferably of at most 500 pm, particularly preferably of at most 250 pm in all three spatial directions. As already mentioned, the at least one micro-optical element has a mechanical connection to a probe head.The term "probe head" refers to a part of the optical probe that is configured to control and move the at least one micro-optical element and to receive a response from the at least one micro-optical element. For this purpose, the probe head can have a plurality of mechanical, electrical, or optical components. In a particularly preferred embodiment, the probe head can have at least one actuator element, which is preferably configured such that the probe head, and thus the at least one micro-optical element mechanically connected to the probe head, can be moved in at least three degrees of freedom, in particular in at least one rotational degree of freedom and in at least two translational degrees of freedom. However, further functions of the probe head are conceivable.In a particular embodiment, the optical probe can comprise at least one additional probe head, which is coupled simultaneously with the probe head to the at least one micro-optical component. This can, in particular, increase coupling efficiency with simultaneous transmission of light from the probe head to the at least one micro-optical component and from the at least one micro-optical component to the additional probe head. However, other applications are conceivable.

[0030] In a particularly preferred embodiment, the probe head can comprise at least one optical fiber or an array of optical fibers. The term "optical fiber" here refers to an elongated structure, preferably made of glass, which has a fiber core that has a higher refractive index than the part of the fiber surrounding the fiber core, whereby light can be guided in the fiber core, preferably in a single mode. This at least one optical fiber can preferably be single-mode or multi-mode. In addition, the probe head can have at least one further optical or optoelectronic component, in particular selected from a laser, photodetector, mirror, optical lens, photonic integrated circuit, spot size converter, ion exchange element such as ioNext, or waveguide component, which was preferably produced by means of a laminated process or by laser processing.However, the use of another optical or optoelectronic component is conceivable.

[0031] As already mentioned, the present optical probe comprises at least one sensor structure separate from the at least one micro-optical element, which is configured to generate a sensor signal indicating a positioning of the probe head relative to an object. As explained in more detail below, in a particularly preferred embodiment, the at least one sensor structure can be manufactured using a direct printing process. The term "separate" emphasizes the fact that the at least one sensor structure and the at least one micro-optical element are neither the same element nor a one-piece molded element, but rather at least two different elements.This is independent of whether the at least one micro-optical element and the at least one sensor structure are produced individually or jointly, in particular by means of a direct printing process, and whether both the at least one micro-optical element and the at least one sensor structure comprise at least one photo-curing material.

[0032] In a particular embodiment, the optical probe can have at least two probe heads, each probe head having at least one micro-optical element and at least one separate sensor structure. For details, please refer to the exemplary embodiments below.

[0033] By means of the at least one sensor structure, the optical probe can be configured, in particular, to prevent contact or collision of the at least one micro-optical element with an object. The terms "contact" or "collision" refer to an unintentional contact of the at least one micro-optical element with an object. Furthermore, the term "object" refers to an object or a part, in particular a structure or a surface, of the object that surrounds the at least one micro-optical element and is located within a range of the probe head, in particular within a range of the at least one actuator element encompassed by the probe head.The object can be, in particular, dirt, an unetched residue of a deep etch, resist residue, an end of an etching trench, residues of electrical contacts, a partial region of the at least one micro-optical component, in particular a surface, a sidewall, a facet, or an edge of the at least one micro-optical component, or a partial region of a wafer on which the at least one micro-optical component is arranged. The term "facet" refers to a surface through which light passes and / or lies within a coupling point and / or has an angle of less than 80° to such a surface. Other types of objects with which contact or collision of the at least one micro-optical element is to be avoided are conceivable.

[0034] In a particularly preferred embodiment, the sensor signal can be generated as a function of the distance between the probe head and the object. A non-contact optical distance measurement, preferably a time-of-flight measurement or an interferometric measurement, can be used here. Alternatively or additionally, the sensor signal can be generated by bending a part of the probe head, wherein the sensor signal can preferably be measured using a force sensor. A sensitivity of 10 mN, particularly preferably 1 mN, in particular 100 nN can preferably be achieved here. In a particular embodiment, the sensor structure can additionally be configured to generate a further sensor signal that indicates a positioning of the probe head relative to the at least one micro-optical component.For this purpose, the at least one sensor structure can be configured as a proximity sensor configured to measure a distance to the at least one micro-optical element or a subregion thereof. In a particular embodiment, a calibration signal can be generated by moving the probe head toward the at least one micro-optical element until the at least one sensor structure indicates a sensor signal.

[0035] Alternatively or additionally, the sensor signal can indicate contact of the at least one micro-optical element with the object. Contact of the at least one sensor structure with the object can cause a bending of part of the probe head. Further alternatively or additionally, the sensor signal can be configured to stop or reverse a movement of the probe head and then transfer it to a position spaced from the object, in particular to prevent damage to the at least one micro-optical element or a sub-region thereof. In a particular embodiment, a deformation of the at least one sensor structure can occur and as a result, a sensor signal can be generated directly and / or by means of a force sensor, which sensor signal can be used to prevent contact or collision of the at least one micro-optical element with an object.

[0036] The at least one sensor structure can in particular be selected from an optomechanical element, an optical element, or a mechanical element. While the term "mechanical element" refers to a component that functions mechanically, and the term "optical element" denotes a component that functions optically, the term "optomechanical" indicates that both a mechanical and an optical aspect are required for functionality. In a preferred embodiment, the at least one sensor structure can be designed as an optomechanical element based on the disclosure of DE 10 2017 221 952 B3. This enables a positioning accuracy of 0.1 nm to 10 nm, in particular of 0.5 nm to 5 nm, to be achieved.

[0037] The at least one sensor structure can preferably have a low mass so that the probe head can be moved with higher acceleration, in particular to enable the highest possible dynamic range for detecting the movement of the probe head. In a particularly preferred embodiment, the at least one sensor structure can have a mass of at most 1 mg, preferably of at most 1 pg, particularly preferably of at most 100 ng.

[0038] The at least one sensor structure can, in particular, be very small, allowing the probe head to have a small size, thus opening up further applications. Preferably, the at least one sensor structure can have a size of at most 300 pm, particularly preferably of at most 200 pm, in particular of at most 100 pm.

[0039] In a particularly preferred embodiment, the at least one sensor structure can be very precisely aligned with the probe head and / or the at least one micro-optical element, particularly since these were manufactured in a single work step. The alignment accuracy can preferably be 10 pm, particularly preferably 5 pm, in particular 1 pm.

[0040] The at least one sensor structure can particularly preferably be configured to achieve the highest possible positioning accuracy of the at least one sensor structure with respect to the object. In a particularly preferred embodiment, the positioning accuracy of the at least one sensor structure with respect to the object can be at most 500 pm, particularly preferably at most 20 pm, in particular at most 1 pm.

[0041] In a preferred embodiment, the at least one micro-optical element can have both at least one reflective surface and at least one refractive surface, in particular a lens. In this embodiment, the at least one micro-optical element can preferably generate a mode field diameter that can assume a value from twice the value to ten times the value of the wavelength used, wherein a value of 350 nm up to and including 4 pm can be selected for the wavelength. The term "mode field diameter" refers, in the case of an approximately Gaussian intensity distribution, to a diameter of a line of the same intensity at 1 / e 2(approximately 13.5%) of the maximum intensity of the light distribution at an optical coupling point of the circle or semi-axes of the corresponding ellipse in an elliptical mode field. Preferably, the mode field diameter can be determined at a beam waist; for this purpose, a plane along a propagation direction of a beam in which the wavefronts are essentially flat and the mode field diameter is minimal can be used. For non-Gaussian mode fields, the mode field diameter is determined by the second-order moment, in particular the standard deviation, of the intensity distribution. For this purpose, four times the second-order moment is used, which for Gaussian mode fields corresponds to l / e 2 -diameter corresponds.

[0042] In a further aspect, the present invention relates to a method for producing an optical probe, in particular the optical probe described in more detail above or below, which is configured for optical coupling to at least one micro-optical component.The present method comprises the following steps, which are preferably carried out in the specified order, beginning with step a) and ending with step c), wherein one or more, in particular consecutive steps, can also be carried out at least partially simultaneously: a) providing a probe head; b) providing at least one micro-optical element which has a mechanical connection to the probe head and which is configured to establish an optical coupling to the at least one micro-optical component; and c) generating at least one sensor structure separate from the at least one micro-optical element, which is configured to generate a sensor signal indicating a positioning of the probe head relative to an object.

[0043] In a particularly preferred embodiment, a direct-writing optical lithography process can be used to produce the at least one sensor structure according to step c). In addition, the at least one micro-optical element according to step b) can also be produced using the direct-writing process. It is particularly preferred if both the at least one micro-optical element and the at least one sensor structure are produced together using the direct-writing process, particularly preferably in one work step. The term "in one work step" means in particular that the components in question are located in a coordinate system or a numerical translation, rotation, or affine mapping to one another, or are produced directly one after the other.By jointly manufacturing both the at least one micro-optical element and the at least one sensor structure in a single manufacturing step, the at least one micro-optical element and the at least one sensor structure are very precisely aligned both with the probe head and with each other. An alignment accuracy of at least 1 pm, preferably 100 nm, can be achieved.

[0044] According to the invention, the at least one sensor structure and / or the at least one micro-optical element comprise a photocuring material, in particular an acrylate, preferably the at least one sensor structure. In a preferred embodiment, both the at least one micro-optical element and the at least one sensor structure can be produced in-situ on the facet in one process step using a direct-writing lithography process. For this purpose, a liquid acrylate can preferably be polymerized, for which purpose two- or multi-photon polymerization can preferably be used.

[0045] In a particular embodiment, the probe head can be fixed relative to an objective, in particular a lithography objective. The objective enables detection of at least one optical coupling point, in particular by coupling light from the at least one optical coupling point into the objective or from the objective into the at least one optical coupling point, reflecting it within the probe head, and then coupling it back into the objective. Alternatively or additionally, at least one marker aligned relative to the at least one optical coupling point, or at least one micro-optical element, or an optically visible feature of the at least one optical coupling point, or an optically visible feature of the probe head, or another optical coupling point of the probe head can be detected. The at least one sensor structure can then be produced using a direct-writing process.For this purpose, an additive lithography process or a subtractive lithography process can be used. The at least one micro-optical element can be produced simultaneously or subsequently.

[0046] In a particularly preferred embodiment, polymerization of a multi-photon process can be used to produce the at least one sensor structure in contact with the probe head. For this purpose, the probe head is first localized relative to an objective. The term "localization" refers to determining the position of one component relative to another component in space. Camera-based, confocal, or fluorescence microscopy methods can preferably be used for this purpose. A light-curing material in contact with the probe head, which can be liquid, gel-like, or solid, is cured using a laser, which can preferably generate short pulses of 50 fs to 1000 fs. For this purpose, the laser can be focused into the light-curing material, preferably using an immersion objective.The focal point can then be moved relative to the probe head along a preprogrammed trajectory such that the at least one sensor structure cures. This preferably involves polymerization of an acrylate-based photoresist. The term "light-curing" here means that an increase in the viscosity or hardness of a material occurs through irradiation with light, whereby, in particular, a material that may be liquid, gel-like, or solid becomes solid. For further details regarding the present method, reference is made to the description of the optical probe.

[0047] The present invention can be used in particular in the manufacture and testing of micro-optical components for communications, sensor technology, medical sensor technology, and diagnostics. However, other applications are conceivable.

[0048] Advantages of the invention

[0049] The present invention has a number of advantages over the optical probes known from the prior art for optical coupling to at least one micro-optical component. In particular, if the at least one probe head moves within or outside a deep etch, or is guided into or out of the deep etch, contact or collision of the micro-optical elements with an object, in particular at least one wall of the deep etch or at least one other component, including a part of the wafer or dirt, etching residues, or resist residues inadvertently present on the wafer, can be avoided. In particular, detection of movement of the at least one probe head in at least a partial region above the wafer is also possible.In particular, this ensures that damage to the micro-optical elements due to incorrect programming of the movement or incorrect manual movement of the at least one probe head, which could lead to a collision, is avoided. In particular, it reliably ensures that the performance of the at least one probe head and the micro-optical elements does not change during a measurement in a manner relevant to the measurement. Furthermore, a plurality of, preferably at least 1000, measurements can be performed simultaneously at a plurality of, preferably at least 1000, optical coupling points on a plurality of, preferably at least 1000, micro-optical components.

[0050] Furthermore, the micro-optical elements can approach at least one micro-optical component or one of its optical coupling points to within a few micrometers, in particular 5 pm to 100 pm, without contact or collision between the at least one micro-optical component and the at least one optical coupling point or the optical facet occurring. Furthermore, objects 1 pm to 500 pm in size can be detected by means of the optical probe and the at least one micro-optical element can be protected from collision with the wafer. The optical probe can achieve a detection accuracy of better than 50 pm, preferably better than 10 pm, in particular better than 1 pm. Furthermore, the optical coupling can be effected via the optical facet.Thus, the at least one micro-optical element can efficiently and reproducibly couple light between the probe head and the at least one micro-optical component, wherein the at least one micro-optical element can generate a focus with a mode field diameter of 3 pm or less, particularly at a wavelength of 1250 nm to 1650 nm. In general, the micro-optical element can achieve a mode field diameter up to the wavelength used; this also applies to wavelengths outside the stated range of 1250 nm to 1650 nm.

[0051] Herein, the terms "have," "have," "comprise," or "include," or any grammatical variations thereof, are used non-exclusively. Accordingly, these terms can refer both to situations in which, besides the features introduced by these terms, no further features are present, or to situations in which one or more further features are present. For example, the expression "A has B," "A has B," "A comprises B," or "A includes B" can refer both to the situation in which, apart from B, no further element is present in A (i.e., a situation in which A consists exclusively of B), and to the situation in which, in addition to B, one or more further elements are present in A, for example, element C, elements C and D, or even further elements.

[0052] Furthermore, it should be noted that the terms "at least one" and "one or more," as well as grammatical variations of these terms, when used in connection with one or more elements or features and intended to express that the element or feature may be provided singly or multiple times, are generally used only once, for example, when the feature or element is first introduced. When the feature or element is subsequently mentioned again, the corresponding term "at least one" or "one or more" is generally no longer used, without limiting the possibility that the feature or element may be provided singly or multiple times.

[0053] Furthermore, the terms "preferred", "preferably", "in particular", "for example" or similar terms are used herein in connection with optional features, without limiting alternative embodiments. Thus, features introduced by these terms are optional features, and these features are not intended to limit the scope of the claims and in particular the independent claims. Thus, as those skilled in the art will recognize, the invention can also be carried out using other embodiments. Similarly, features introduced by "in an embodiment of the invention" or by "in an embodiment of the invention" are understood to be optional features, without limiting alternative embodiments or the scope of the independent claims.Furthermore, these introductory expressions are intended to leave untouched all possibilities of combining the features introduced thereby with other features, whether optional or non-optional.

[0054] Short description of the characters

[0055] Further details and features of the present invention will become apparent from the following description of a preferred embodiment, particularly in conjunction with the dependent claims. The respective features can be implemented individually or in combination with one another. The invention is not limited to the embodiments. The embodiments are schematically illustrated in the following figures. Like reference numerals in the figures denote like or functionally identical elements, or elements that correspond to one another in terms of their functions. In detail:

[0056] Figures 1 and 2: each show a section through an embodiment of an optical probe before (Figure 1) and after (Figure 2) contact with an object;

[0057] Figures 3 to 7 each show a plan view of a further embodiment of the optical probe;

[0058] Figure 8: Section through another embodiment of the optical probe;

[0059] Figure 9: Top view of the fiber array according to Figure 8;

[0060] Figure 10: schematic representation of another embodiment of the optical

[0061] Probe arranged to couple to a grating coupler;

[0062] Figures 11 and 12 each show a section through a further embodiment of the optical probe;

[0063] Figure 13: schematic representation of a method for manufacturing an optical probe;

[0064] Figures 14 to 16 each show a view of a further embodiment of the optical probe;

[0065] Figure 17: schematically shows a method for detecting a sensor signal;

[0066] Figure 18: an exemplary measurement of a feedback efficiency;

[0067] Figures 19 and 20 show another embodiment of the optical probe; and

[0068] Figure 21 further embodiments of the sensor structure.

[0069] Description of the Embodiments Figure 1 shows a section through an embodiment of an optical probe 1 configured for optical coupling to a micro-optical component 50. This allows at least one element 56 of the micro-optical component 50 to be subjected to a test. The optical probe 1 comprises a probe head 10, which in the present embodiment is designed as an optical fiber 12. As schematically illustrated, this is a single-mode fiber comprising a fiber core 13. The optical fiber 12 is connected, directly or by means of a suitable device, to a force sensor 27.

[0070] The optical probe 1 illustrated by way of example in Figure 1 further comprises a micro-optical element 20, which is located on the probe head 10 and is thus mechanically connected to the probe head 10. The micro-optical element 20 is designed as a combination of a reflective surface 23 and a refractive surface 24, here as a lens, which serve to establish an optical coupling between an optical coupling point 14 of the probe head 10 and the micro-optical component 50. In the embodiment according to Figure 1, the lens is configured to generate mode fields at the coupling point 51 on the micro-optical component 50.

[0071] The optical probe 1 illustrated by way of example in Figure 1 further comprises a sensor structure 21 separate from the micro-optical element 20, which is configured to generate a sensor signal indicating a positioning of the probe head 10 relative to an object 100. The probe can also have (not shown) multiple micro-optical elements 20 and / or multiple sensor structures 21. The sensor structure 21, which is located on the probe head 10 embodied as an optical fiber 12, is designed here as a protective structure 26, which is configured to protect both the probe head 10 and the micro-optical element 20 from contact and collision.The sensor structure 21 surrounds the micro-optical element 20 in such a way that it prevents contact with the object 100, while at the same time not preventing the micro-optical element 20 from penetrating a deep etching 55 and establishing the optical coupling between the optical coupling point 14 of the probe head 10 and the optical coupling point 51 of the micro-optical component 50. Upon contact of the sensor structure 21, embodied as a protective structure 26, with the object 100, the force sensor 27 can generate a sensor signal 40, which can be used to stop or reverse a movement of the probe head 10 and subsequently move the probe head 10 to a position spaced apart from the object 100.In a preferred embodiment, the sensor structure 21 can have reinforcements 15, which can be configured to enlarge a contact area between the sensor structure 21 and a facet 103 and thus increase absolute adhesion between the sensor structure 21 and the object 100. In the embodiment according to Figure 1, the micro-optical component 50 is part of a wafer 60, wherein the optical coupling point 51 has been exposed by performing the deep etching 55. Furthermore, further optical components 61 can be part of the wafer 60, in particular part of the micro-optical component 50. The deep etching 55 can typically have a width 201 of 50 pm up to and including 500 pm and a depth 202 of 3 pm up to and including 200 pm.

[0072] Figure 2 shows a further section through the optical probe 1 according to Figure 1, after contact or a collision of the sensor structure 21 with the object 100 occurred. A collision force generated thereby caused a deformation 36 of the sensor structure 21, and the sensor structure 21 was deflected from its rest position 37, whereby a force acts on the probe head 10 as the sensor signal 40, which can be detected by the force sensor 27. Alternatively or additionally, the probe head 10, a holder in which the probe head 10 is fixed, or the force sensor 27 can bend. The movement of the probe head 10 can be stopped by evaluating the measured force.

[0073] Figure 3 shows a schematic top view of another embodiment of the optical probe 1, after the probe head 10 has been inserted into the deep etching 55 and coupled to the micro-optical component 50 at the optical coupling point 51. Following this, it is intended that the probe head 10 is also coupled to further optical coupling points 52, 53 of the micro-optical component 50 and moved further in direction 62. In the event that contact occurs between the sensor structure 21 and the object 100, the contact can be detected by the force sensor 27 and cause the movement of the probe head 10 to stop.Alternatively or additionally (not shown), contact between the sensor structure 21 and the object 100 can be established by measuring an electrical resistance between the sensor structure 21 and the micro-optical component 50. In this embodiment, the sensor structure 21 preferably has a metallic coating to provide increased electrical conductivity. Further alternatively or additionally (not shown), contact between the sensor structure 21 and the object 100 can be detected by means of a vibration measurement or by observation using a camera.

[0074] Figure 4 shows a schematic plan view of a further embodiment of the optical probe 1, in which the micro-optical element 20 has additional alignment structures 22, which are located in a known spatial position with respect to the probe head 10 and the sensor structure 21. The alignment structures 22 can be configured to align the probe head 10 with respect to the micro-optical component 50. For this purpose, in particular, the alignment structures 22 can be detected with a first camera, while markers on the micro-optical component 50 can be detected with a second camera. Once the two cameras have been calibrated with respect to their position relative to one another, the probe head 10 can be aligned with respect to the micro-optical component 50 using the alignment structures 22.

[0075] Figure 4 shows a preferred embodiment of the sensor structure 21, in which light from an optical waveguide 25 can be optically coupled between optical fibers 63, 64. If the single-mode or preferably multi-mode optical waveguide 25 comes into contact with an object, an amount of coupled light between the optical fibers 63, 64 changes, whereby the change can be used as the sensor signal 40 in order to prevent contact of the micro-optical element 20 with the object. Alternatively, feedback caused by contact in the optical fiber 63, 64 can be measured. In a further embodiment (not shown), a polarization of the light optically coupled between the optical fibers 63, 64 can be measured and used as the sensor signal 40.Since bending of the optical waveguide 25 causes birefringence, a highly sensitive sensor signal can be generated when the optical waveguide 25 comes into contact with an object. In a further embodiment (not shown), the optical waveguide 25 can also be connected to a location of sufficiently high reflectivity, in particular air, instead of to the fiber 64, which can cause a reflectivity of 3% to 4%. In this embodiment, a back reflection of a signal within the optical waveguide 25 can be used as the sensor signal 40 for the contact of the optical waveguide 25 with an object.

[0076] Figure 5 shows a schematic plan view of a further embodiment of the sensor structure 21, which is designed as a protective structure 26 to protect the micro-optical element 20 from contact with an object, but does not exclude the possibility of inserting the micro-optical element 20 into the deep etching 55, moving it within the deep etching 55, and establishing an optical coupling to the micro-optical component 50. Optionally, the optical fibers 12, the fiber core 13, and / or the optical coupling point 14 can be equipped with sensor structures 21 in the form of lenses or combinations of lenses and mirrors (not shown) in order to measure the distance to an object 100 in a contactless manner at at least one, preferably at least two, locations.

[0077] Figure 6 shows a schematic plan view of a further embodiment of the optical probe 1, in which a sensor structure 21, 35 is configured to generate and detect at least one optical sensor signal 28, 29, 30, 31 in order to thereby detect the object 100 (not shown here) or to enable alignment of the probe head 10 with the object 100. In this embodiment, the sensor structure 21, 35 is configured to generate the sensor signal 28, which can detect the object 100 in an acceptance cone 32. The acceptance cone 32 can be defined when the sensor structure 21, 35 is defined and can span a half-space above the facet 103. This can preferably be achieved by using optical lenses with a high numerical aperture (NA), in particular above NA = 1.5, in combination with the reflective surface 23 with total internal reflection.In a further embodiment, also shown schematically in Figure 6, a sensor structure 21, 34 can receive and / or transmit sensor signals 30, 33.

[0078] Figure 7 shows an application of the embodiment of the optical probe 1 shown in Figure 6 for optical coupling at the optical coupling point 51 in the deep etching 55. Here, the sensor signal 31 can be used to regulate a distance of the probe head 10 from a bottom surface 57 of the deep etching 55, with the sensor signal 28 serving to detect the object 100 (not shown) and thus, as far as possible, to avoid contact of the micro-optical element 20 with the object 100. The object 100 can be a structure that was inadvertently not deep-etched, or it can be considerably smaller than shown in Figure 1.

[0079] Figure 8 shows a section through a further embodiment of the optical probe 1, in which the micro-optical element 20 comprises the refractive surface 24, here embodied as a lens, which is fixed to the optical fiber 12 of a fiber array 11. This is a so-called "lensed fiber," which is typically used to contact the micro-optical component 50 at the optical coupling point 51. The sensor structure 21, embodied as a protective structure 26, can prevent damage to the micro-optical element 20, for example, due to an accidental collision between the micro-optical element 20 and the facet 103.During a coupling process, an area around the micro-optical element 20 and the optical coupling point 51 can be observed using a microscope to detect contact between the sensor structure 21 and the facet 103 due to bending of the probe head 10, the fiber array 11, or the sensor structure 21. The embodiment can also be used for coupling to a grating coupler (not shown), wherein the fiber core 13 is positioned at an angle, preferably from 5° to 20°, to a normal of a wafer.

[0080] Figure 9 shows a plan view of the fiber array 11 encompassed by the probe head 10 from

[0081] Figure 8 along a surface 200 in Figure 8. From this it can be seen in particular that the sensor structure 21 designed as a protective structure 26 cannot impair the functionality of the refractive surface 24 encompassed by the micro-optical element 20.

[0082] Figure 10 shows a section through a further embodiment of the optical probe 1, which is configured for coupling to a grating coupler 54. The grating coupler 54 is comprised of a waveguide, which is comprised of the micro-optical component 50, which is preferably comprised of a wafer 60. To prevent a collision of the optical probe 1 with the wafer 60, the fiber array 11 can preferably be equipped with a chamfer 104. The chamfer 104 is preferably 400 pm, particularly preferably 250 pm, in particular 60 pm, away from the fiber core 13.

[0083] Figure 11 shows a section through a further embodiment of the optical probe 1, in which the micro-optical component 50 has two opposing coupling points 51, 52, which are coupled to the two independently movable probe heads 10, 16. This allows a separate optimization of the coupling efficiency of the probe head 10 to the micro-optical component 50 and of the micro-optical component 50 to the probe head 16, so that an optimum coupling efficiency can be achieved for both optical couplings. This embodiment can be used in particular to test the element 56 of the micro-optical component 50, wherein the element 56 serves as an optical semiconductor amplifier.semiconductor optical amplifier (SO A); however, the use of another element is conceivable, in particular DFB lasers with two output facets or other components with at least two opposing coupling points.

[0084] Figure 12 shows a section through a further embodiment of the optical probe 1, in which the sensor structure 21 is designed as a cantilever beam 38 that bends upon contact with the object 100. The bending of the cantilever beam 38 can be detected by a sensor structure 39 located on a further optical fiber 17. For this purpose, in particular, a standing wave can form between the sensor structure 39 and the cantilever beam 38, caused by a reflection from the sensor structure 39 and the cantilever beam 38. As a result, depending on the magnitude of the bending of the cantilever beam 38, the amount of light provided by the further optical fiber 17 and coupled back into the further optical fiber 17 can change. For this purpose, a wavelength can preferably be used at which the change in the light coupled back into the further optical fiber 17 reacts as sensitively as possible to the bending of the cantilever beam 38.Alternatively or additionally, the cantilever beam 38 can be excited to oscillate by means of another signal, and a change in the oscillation amplitude of the cantilever beam 38 can be measured by the sensor structure 39 as the cantilever beam 38 approaches the object 100. This allows forces below 100 nN to be measured. This procedure is known in atomic force microscopy as "dynamic mode."

[0085] Figure 13 schematically shows an embodiment of a method for producing the optical probe 1, which is configured for optical coupling to a micro-optical component (not shown). The probe head 10 is localized using a lithography objective 300. For this purpose, in particular, an optical facet of the fiber array 11 or the optical coupling point 14 can be detected. The lithography objective 300 focuses a light beam, preferably selected from a UV beam or a laser beam, in particular an fs laser beam, at a focal point 301. In the present direct-writing method, curing of a curable material 302 caused by the light beam takes place at the focal point 310. By spatially moving the focal point 301, a provided sensor structure 303 can be generated and structured.The illustration according to Figure 13 further shows a portion 304 of the already produced sensor structure 21 already cured. In a particularly preferred embodiment, both the sensor structure 21 and the micro-optical element 20 can be produced together using the direct-writing process; however, production of the micro-optical element 20 after or preferably before the production of the sensor structure 21 is possible.

[0086] Figure 14a shows a schematic plan view of another embodiment of the optical probe 1, in which the fiber array 11 is provided with a bevel 104, so that the fiber array 11 can be positioned at an angle to the surface of the wafer 60 that differs from 90°. An angle of 5°, as shown in Figure 14a, is particularly preferred; however, angles from 1° up to and including 45° can also be preferably set.

[0087] Figure 14b shows a further embodiment of the optical probe 1, in which an optical fiber is preferably located in the same probe head 10 as in Figure 14a. The illustration according to Figure 14b represents a sectional image through a sectional plane which is located in or in front of the drawing plane shown in Figure 14. Preferably, a plurality of sensors 21 are used which are configured to detect any tilting that occurs. Another possibility for detecting any tilting that occurs is to tilt the probe head 10 relative to the wafer 60 so that the sensor signal 31 reflected on the wafer 60 is maximized. The angle makes it possible to detect a marker structure 401 with a top-view camera, i.e. a camera that is configured to view the surface of the wafer 60. This embodiment can simplify the alignment of the probe head 10 to the wafer 60.Due to the tilt, a refractive surface 24 that is non-perpendicular to the direction of light propagation is preferably used, so that the sensor signal 31 impinges perpendicularly on the bottom of the deep etching 55. This design has the advantage that reflections from the refractive surface 24 cannot couple back into the fiber core 13. This avoids interference signals due to light reflected from the wafer 60 and the refractive surface 24.

[0088] Figure 15 shows a schematic plan view of a further embodiment of the optical probe 1, in which a further optical fiber is configured to detect a distance from the wafer 60 at two positions comprising the sensor structures 520, 522, thereby generating sensor signals 521, 523. In this way, it is possible to detect and correct the tilt of the probe head 10 relative to the wafer 60. For this purpose, 2D fiber arrays are preferably used, particularly preferably with two rows of fibers in one direction and more fibers, in particular 8 or 64, in a further direction pointing into the illustrated drawing plane in Figure 15. In a further preferred embodiment (not shown), the micro-optical element 20 can be used instead of the sensor structure 520.

[0089] Figure 16 shows a schematic plan view of another embodiment of the optical probe 1, in which a facet 530 is located at an angle 550 deviating from 90° to the facet 530. This allows back reflections at the probe head 10, in particular at the sensor signal 521 and the refractive surface 24, to be suppressed. This prevents interference from portions of the sensor signal 521 reflected at the wafer 60 and at the refractive surface 24 and / or at the facet 530. As a result, no optical cavities are formed, so that no periodic oscillations can be observed during the detection of the sensor signal 521 depending on the distance of the probe head 10 from the wafer 60.

[0090] Figure 17 schematically shows a method for detecting a sensor signal 28, 29, 30, 31, 521, 522. For this purpose, light 503 propagating to a detector from a light source 501 is directed by a circulator or splitter 504 through the optical fiber 17 and the sensor structure 21 onto the surface of the micro-optical component 50, in particular the wafer 60. There, the sensor signal 28, 29, 30, 31, 521, 522 is reflected and coupled back into the optical fiber 17. The sensor signal 28, 29, 30, 31, 521, 522 is directed to a detector by the circulator or splitter 504.If the micro-optical component 50, in particular the wafer 60, is located exactly in a beam waist of the imaging of light from the fiber core 13 onto the surface of the micro-optical component 50, in particular the wafer 60, by the sensor structure 21, so that the length 511 of a free beam path of the sensor signal in micrometers corresponds exactly to the distance 512 of highest back coupling, the back reflection is maximum. This allows the distance of the sensor structure 21 and / or the sensor head 10 to the micro-optical component 50, in particular the wafer 60, to be measured, since this point of best coupling is known or has been previously calibrated.

[0091] Figure 18 shows an example measurement of a feedback efficiency, i.e., a ratio 510 of the power of the light 503 propagating to the detector and the light 504 coming from the detector, as a function of the length 511 of the free beam path of the sensor signal in micrometers. If the micro-optical component 50, in particular the wafer 60, is located exactly at the distance 512 of highest feedback, this feedback is maximum, which can be used as a calibration point for the distance of the micro-optical component 50, in particular the wafer 60, from the probe head 10. In Figure 18, the dashed line shows simulation data, and the dots show measured values. For these measurements, the embodiment of the optical probe 1 according to Figure 15 was used.Due to interference between light reflected from the facet of the probe head 103 and from the micro-optical component 50, in particular the wafer 60, an oscillation can occur, which causes a vertical scattering of the measurement points that is periodic with the length 511 of the free beam path of the sensor signal. This scattering can be avoided by an embodiment of the optical probe 1 according to Figure 16. Alternatively, interference can be avoided by using a broadband light source. Furthermore, the light source 501 can be designed as a tunable laser, e.g., as an "External Cavity Laser (ECL)" or as a "Swept Source" laser. If a period 620, in particular an oscillation period as a function of the wavelength, is measured for a fixed distance 511, as shown in Figure 21c, a value for the distance 511 can also be determined.The distance 510 is determined using the period 620, with a smaller period indicating a larger distance and the distance 510 being inversely proportional to 620. The distance thus determined can be used as a calibration signal for the sensor. In a preferred embodiment, the maximum of the ratio 510 can be used for aligning the probe head 10 to the micro-optical component 50, in particular the wafer 60.

[0092] Figure 19 shows a further embodiment of the optical probe 1, in which the sensor structure 21 comprises two parts 520, 520b. The parts 520, 520b of the sensor structure 21 are designed such that the coupling of the light 504 coming from the detector into the optical fiber 17 is maximum when the surface of the micro-optical component 50, in particular of the wafer 60, is located at the distance 512 of highest back coupling. However, if the surface of the micro-optical component 50, in particular of the wafer 60, is located at a position 560 that deviates from the distance 512 of highest back coupling, the sensor signal is reduced. This embodiment has the advantage over the embodiment of Figure 17 that it can be more sensitive while maintaining a high working distance and that fewer limitations can occur due to interference between parts of the probe head 10 and the micro-optical component 50, in particular the wafer 60.

[0093] Figure 20 shows a further embodiment of the optical probe 1, in which shorter working distances and a flatter angle of the sensor signal 521 with respect to the surface of the micro-optical component 50, in particular of the wafer 60, preferably more than 45° to the normal to the surface of the micro-optical component 50, in particular of the wafer 60, occur, so that the parts 520, 520b of the sensor structure 21 can also be implemented by reflective surfaces.

[0094] Furthermore, with respect to the surface of the micro-optical component 50, in particular of the wafer 60, p- and s-polarized light can be used, and the difference between p- and s-polarized light can be analyzed. Preferably, the ratio of the reflection of p- and s-polarized light at an angle of 45° to the normal to the surface of the micro-optical component 50, in particular of the wafer 60, can be analyzed. Assuming that the surface of the micro-optical component 50, in particular of the wafer 60, is an oxide, the ratio of s- and p-polarized light changes by more than 1% for an angle change of 1°. Furthermore, by analyzing the ratio of p- and s-polarized light, conclusions can be drawn about the material properties of the micro-optical component 50, in particular of the wafer 60, wherein in particular a distinction can be made between metal, oxide, different oxide layers, and semiconductors, preferably silicon.In this case, the fiber core 13 can preferably be designed as a polarization-maintaining beam splitter. Furthermore, the probe head 10 can preferably have polarization-sensitive beam splitters.

[0095] Figure 21a shows a further embodiment of the sensor structure 21. In order to achieve high position resolution, interference between the micro-optical component 50 and a part of the probe head 10 can also be used. Preferably, the interference occurs between a surface of the micro-optical component 50 and an interface on or within the sensor structure 21. In this case, a light component 610 reflected at a facet and a light component reflected at the micro-optical component 50 interfere. The sensor structure 21 is preferably designed such that the light intensity of the two light components 601, 602 is exactly the same, so that a large modulation occurs when the distance between the probe head 10 and the micro-optical component 50 changes.Figure 21b shows a further embodiment of the sensor structure 21, in which a cavity 610 causes a reflection in the form of a light component 603, which is preferably adapted to the reflection of the light component 602, so that their intensities are exactly the same. The cavity 610 can preferably have a surface that is perpendicular to the light propagation direction and another surface that is tilted at least 5° relative to it. Instead of the cavity 610, a diffractive structure (not shown) can also be used.

[0096] Fig. 21c shows that the interference of light intensities reflected by the micro-optical component 50 and one within the probe head 10 results in a light intensity that periodically oscillates with the distance between the probe head 10 and the micro-optical component 50, which can preferably be detected using the embodiment according to Figure 17. This oscillation has a period of approximately half the light wavelength of the sensor signal 28. This oscillation can be superimposed on an intensity curve according to Figure 18 and can also amount to only a fraction of less than 5% of the intensity distribution shown in Figure 18. Whether the oscillation according to Figure 21c is visible or not can be adjusted by the optical coherence length of the sensor signal 28 and the design of the sensor structure 21, whereby for maximum oscillation, the reflections of the light components 602, 603 are exactly the same.A period 620 can be set by the wavelength of the sensor signal 28. The period 620 corresponds to a distance between adjacent maxima and thus approximately half the used wavelength, e.g., 775 nm for a wavelength of 1550 nm. A change in the wavelength of the sensor signal 28 results in a periodic change in the light output 615. The period of the oscillation of the light output 615 depends on the distance between the reflection surfaces that generate the light components 601, 602, 603. This period can be used to determine the distance between the probe head 10 and the micro-optical component 50 and to use this as a calibration signal for the signal according to Figure 18.

[0097] In a preferred embodiment, the signal according to Figure 21c can be used to detect mechanical vibrations that can change the distance between the probe head 10 and the micro-optical component 50. Other sensor signals, in particular according to Figure 18, can also be used for this purpose. The measurement can also be carried out in multiple spatial directions according to Figure 7. These vibrations can be compensated for by a fast actuator 700 with a high control bandwidth in at least one spatial direction, preferably in multiple spatial directions, so that the distance and / or orientation of the probe head 10 to the micro-optical component 50 now remains constant. The actuator 700 preferably has a bandwidth of at least 100 Hz, more preferably of at least 1000 Hz, in particular of at least 20 kHz.In particular, vibrations caused by rapid movements of the optical probe 1 can be compensated, which can occur especially when the optical probe 1 moves to measurement positions for different micro-optical components 50, for example within a wafer 60. This makes it possible to reduce the waiting time between measurements on different micro-optical components 50. Active vibration control also makes it possible to use measuring devices with lower vibration isolation, which are preferably used for purely electrical testing of electrical components. This allows electrical testers to be retrofitted with optical test functionalities. Vibrations can also change the positioning of the probe head 10 relative to the micro-optical component 50 in dimensions other than the distance; for example, vibration can occur in the plane of the micro-optical component 50.The sensor structure 21 cannot necessarily detect these vibrations. To detect these vibrations, an optical probe 1 according to Figure 6 can be used. In a further preferred embodiment (not shown), the sensor structure can detect movements of micro-electro-mechanical systems (MEMS), in particular a functionality of wafer-level MEMS actuators.

[0098] List of reference symbols

[0099] I optical probe

[0100] 10 Probe head

[0101] II Fiber array

[0102] 12 optical fibers

[0103] 13 fiber core

[0104] 14 optical coupling points

[0105] 15 reinforcements

[0106] 16 additional probe heads

[0107] 17 additional optical fibers

[0108] 18 Projection line of a facet

[0109] 19 Volume spanned by the projection line of the facet

[0110] 20 micro-optical element

[0111] 21 Sensor structure

[0112] 22 Alignment structure

[0113] 23 reflective surface

[0114] 24 refractive surface

[0115] 25 optical waveguide

[0116] 26 Protection Structure

[0117] 27 Force sensor

[0118] 28 Sensor signal for detecting an object Sensor signal for detecting a side wall

[0119] Sensor signal for detecting further structures

[0120] Sensor signal for detecting a bottom surface of a deep etching

[0121] Acceptance cone

[0122] Sensor signal to detect further structures in another direction

[0123] Sensor structure

[0124] Sensor structure deformed protection structure

[0125] Rest position of the protective structure

[0126] Cantilever

[0127] Sensor structure

[0128] Sensor signal

[0129] Propagation direction of the sensor signal micro-optical component, 52, 53 optical coupling point of the micro-optical component

[0130] Grating coupler

[0131] Deep etching in a wafer

[0132] Element of the micro-optical component

[0133] Bottom surface of the deep etching

[0134] Waveguide in the micro-optical component

[0135] Wafer additional component as part of the wafer

[0136] Direction of movement of the probe head optical fiber additional optical fiber 0 Object 1 Side wall of a deep etching 2 Facet of the micro-optical component 3 Facet of the probe head 4 Chamfer 0 Projection area 1 Width of a deep etching 2 Depth of a deep etching 0 Perpendicular to the surface of the micro-optical component 1 Optical axis of the probe head 2 Tilt of the probe head with respect to that of the micro-optical component 0 Lithography lens Focus of the lithography lens Light-curing material Intended sensor structure Already manufactured part of the sensor structure

[0137] Marker structure

[0138] light source

[0139] detector

[0140] Light propagating to the detector

[0141] Light coming from the detector

[0142] Circulator or splitter

[0143] Normalized ratio of the amount of light coming from the detector divided by the amount of light propagating to the detector in percent

[0144] Length of a free beam path of a sensor signal in micrometers

[0145] From the distance of highest back coupling further optical fiber, 520b part of the sensor structure

[0146] Sensor signal further sensor structure

[0147] Sensor signal

[0148] Facet that has been ground at an angle to the fiber core that deviates significantly from 90°, in particular more than 1°

[0149] Angle between fiber core and facet

[0150] Position that deviates from the distance of highest recoupling Light fraction reflected at facet Light fraction reflected at micro-optical component Light fraction reflected at cavity

[0151] cavity

[0152] Light output

[0153] Period linear range for vibration measurements

[0154] Actuator

Claims

Patent claims 1. An optical probe (1) configured for optical coupling to at least one micro-optical component (50), the optical probe (1) comprising: - a probe head (10); - at least one micro-optical element (20) having a mechanical connection to the probe head (10) and configured to establish an optical coupling to the at least one micro-optical component (50); and - at least one sensor structure (21) separate from the at least one micro-optical element (20) and configured to generate a sensor signal (40) indicating a positioning of the probe head (10) relative to an object (100), wherein the at least one micro-optical element (20) and / or the at least one sensor structure (21) comprise at least one photo-curing material.

2. Optical probe (1) according to the preceding claim, wherein the at least one sensor structure (21) comprises an optomechanical element, an optical element or a mechanical element.

3. Optical probe (1) according to one of the preceding claims, wherein the at least one sensor structure (21) has a mass of at most 1 mg.

4. Optical probe (1) according to one of the preceding claims, wherein an accuracy of the positioning of the at least one sensor structure (21) with respect to the object (100) is at most 500 pm.

5. Optical probe (1) according to one of the preceding claims, wherein the at least one sensor structure (21) is arranged to - to generate the sensor signal (40) as a function of a distance of the probe head (10) to the object (100); - to indicate contact of the at least one micro-optical element (20) with the object (100) and / or - to stop or reverse a movement of the probe head (10) or a portion thereof and then to transfer it to a position spaced from the object (100).

6. Optical probe (1) according to one of the preceding claims, wherein the at least one sensor structure (21) is further configured to generate a further sensor signal indicating a positioning of the probe head (10) relative to the at least one micro-optical component (50).

7. Optical probe (1) according to one of the preceding claims, wherein the at least one sensor structure (21) comprises the at least one photocuring material.

8. Optical probe (1) according to one of the preceding claims, wherein the at least one micro-optical element (20) has at least one reflective surface (23) and at least one refractive surface (24).

9. Optical probe (1) according to one of the preceding claims, wherein the probe head (10) comprises at least one optical fiber (12).

10. Optical probe (1) according to one of the preceding claims, wherein the sensor structure (21) is configured to detect a vibrational movement between the at least one micro-optical component (50) and the optical probe (1).

11. Optical probe (1) according to one of the preceding claims, comprising at least one further probe head (16) which is coupled simultaneously with the probe head (10) to the at least one micro-optical component (50).

12. A method for producing an optical probe (1) which is configured for optical coupling to at least one micro-optical component (50), the method (400) comprising the following steps: a) providing a probe head (10); b) providing at least one micro-optical element (20) which has a mechanical connection to the probe head (10) and which is configured to establish an optical coupling to the at least one micro-optical component (50); and c) generating at least one sensor structure (21) which is separate from the at least one micro-optical element (20) and is configured to generate a sensor signal (40) which indicates a positioning of the probe head (10) relative to an object (100), the at least one micro-optical element (20) and / or the at least one sensor structure (21) comprising at least one photo-curing material.

13. The method according to the preceding claim, wherein the at least one sensor structure (21) is manufactured using a direct-writing method.

14. The method according to the preceding claim, wherein the at least one micro-optical element (20) is also manufactured using the direct-writing method.

15. Method according to one of the preceding method claims, wherein the at least one micro-optical element (20) and the at least one sensor structure (21) are produced together by means of the direct writing method.

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