Process for producing zonal coatings on optical surfaces

Abstract

The invention relates to a method for producing a zonal optical coating (24) on a substrate (10), in particular an optical surface (10.1) of the substrate (10), comprising - providing (110) a substrate (10) which is non-planar on at least one side and has an optical coating (20), - applying (120) a mask (30) to the optical coating (20) to obtain a masked substrate (11), wherein the mask (30) covers the optical coating (20) in a masked area (21) and does not cover it in an unmasked area (22), - etching (130) the masked substrate (11) to at least partially remove the optical coating (20) depending on the unmasked area (22), thereby producing a masked zonal coating (23), - removing (140) the mask from the masked zonal coating (23) to obtain a zonal optical coating (24).

Description

[0001] The invention relates to a method having the features of the independent method claim and to an optical device having the features of the independent device claim.

[0002] Methods and optical devices with an optical coating are known. For example, an optical device can comprise a substrate, e.g., a lens. An optical coating can, for example, have a mirror coating, in particular an at least partially mirrored region on a surface, e.g., an optical surface, of the substrate. To apply the optical coating to the substrate, a photolithography process (in particular with comparatively high lateral accuracy in the range of approximately 10 µm) or another coating process, in particular by vapor deposition, e.g., by physical vapor deposition (PVD), can be used.

[0003] The current state of the art has disadvantages. Photolithography processes are complex, expensive, and / or complicated. Other coating processes have comparatively low precision, for example, on the order of at least 1 mm. Therefore, smaller structures and / or higher precision cannot be achieved.

[0004] It is therefore an object of the present invention to at least partially overcome at least one of the above-described disadvantages of optical coating methods. In particular, the object of the invention is to provide an improved method for producing a zonal optical coating and an improved optical device, which are preferably more cost-effective and / or more precise.

[0005] The above object is achieved by a method having the features of the independent method claim and by an optical device having the features of the independent device claim. Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the optical device according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other. In particular, advantages described in the context of the first and / or second aspect also apply to the first and / or second aspect.

[0006] The above object is achieved according to a first aspect by a method for producing a zonal optical coating on a substrate, in particular an optical surface of the substrate, comprising - Providing a substrate which is non-planar on at least one side and has an optical coating, - applying a mask to the optical coating to obtain a masked substrate, wherein the mask conceals the optical coating in (and / or by) a masked area and does not conceal it in (and / or by) an unmasked area, - etching the masked substrate to at least partially remove the optical coating depending on the unmasked area, thereby producing a masked zonal coating, - Removing the mask from the masked zonal coating to obtain a zonal optical coating.

[0007] The process and / or the individual steps can be performed repeatedly. The sequence of the process is preferably as shown. However, it is also conceivable to provide a different sequence, especially if technically feasible.

[0008] In the context of the invention, an optical surface and / or optical coating can mean that it is (specially) designed to preferably enable an (intentional, desired and / or technically planned) influence on electromagnetic waves, preferably in the ultraviolet range. For example, an optical surface and / or optical coating can be (at least partially) transparent and / or reflective (e.g., mirrored). For example, a substrate and / or an optical surface of the substrate can have a (ground) lens. For example, an optical coating (see below) can have a mirror coating and preferably reflect electromagnetic waves, preferably in the ultraviolet range, in the direction and / or against the direction of the substrate.The substrate, at least one optical surface of the substrate, the (at least one) optical coating and / or the (further) zonal optical coating can be arranged along an optical axis one after the other, symmetrically with respect to the optical axis and / or (substantially) perpendicular to the optical axis.

[0009] Within the scope of the invention, zonal or zone can comprise a spatial, in particular area-related, limitation, e.g., on or in a zone. A zonal optical coating can be limited to a (specific) zonal region of the substrate and / or the optical coating. In other words, a zonal optical coating can be arranged (only) partially, locally, and / or not across the entire surface. In the simplest case, for example, a zonal optical coating can have a (central and / or centric) hole. For example, an optical coating can initially be provided on the substrate, which is then removed by etching (at least partially, e.g., by etching a hole), thereby creating a zonal optical coating, since, in particular, the optical coating is then arranged (or remains) only in a (specific) zone, e.g., defined by the negative of the mask (see below), of the substrate.In other words, the optical coating can be partially etched away by etching, preferably leaving (only) a zonal optical coating.

[0010] The substrate and / or the optical device can be arranged or used, for example, in an optical system, in particular comprising one or more substrates, for example in a telescope, a microscope, binoculars, spectacles, and the like. The substrate preferably comprises a three-dimensional shape, for example an (optical) lens. The substrate can comprise an optically (at least partially) transparent material, in particular along an optical axis. The substrate can preferably comprise quartz glass and / or SiO2. It is also conceivable for the substrate to comprise quartz glass produced by flame hydrolysis of SiCl4. In this case, the substrate can comprise, for example, UV-transparent quartz glass. Alternatively or additionally, the substrate can comprise calcium fluoride (CaF2) and / or BK7.The substrate can, for example, have a thickness, in particular along an optical axis, between 1 µm to 1 m, in particular between 1 µm to 10 cm, for example between 10 µm to 10 cm, preferably between 100 µm to 5 cm, particularly preferably between 200 µm to 3 cm, ideally between 500 µm to 10 mm.

[0011] An optical surface of the substrate can comprise a surface of the substrate that can be arranged, for example, substantially perpendicular to an optical axis. For example, the substrate can be cylindrical, cuboid-shaped, and / or planar, preferably perpendicular and / or symmetrical to an optical axis. In this case, an (optical) surface can preferably be arranged (substantially) perpendicular to the optical axis. For example, the optical surface can have a polished surface, which influences electromagnetic waves.

[0012] It may be particularly preferred if the substrate is non-planar on at least one side (in particular at least one surface or side of the substrate). In other words, it may be provided that the substrate is not exclusively planar, plane-like, cuboid-shaped, cylindrical and / or disk-like. In the simplest case, for example, the substrate can have a curvature and / or be designed like an (optical) lens. The substrate, in particular an optical surface of the substrate, can have a radius of curvature between 1 µm and 1000 m, in particular between 10 µm and 100 m, for example between 100 µm and 10 m, preferably between 1 mm and 100 cm, particularly preferably between 1 cm and 80 cm, ideally between 2 cm and 75 cm. The substrate, in particular an optical surface of the substrate, can be convex and / or concave at least in sections.It can be provided that the substrate, in particular an optical surface of the substrate, and / or a curvature is adapted to one (in particular all) optical coatings and / or vice versa. For example, these can run or be arranged flush with one another, in particular perpendicular to an optical axis. It can be provided that the substrate, in particular perpendicular to the optical axis, has a variable thickness and / or a variable optical thickness. This can preferably be combined with different or variable thicknesses of an optical coating and / or a zonal optical coating. As a result, an optical influence by the substrate through the optical coating and / or a (further) zonal optical coating can advantageously be reduced or increased (at least in sections).A variable thickness of an optical coating can also advantageously be utilized (alternatively or additionally) by etching. For example, thicker sections of an optical coating can be removed less and / or incompletely by etching. This can, for example, result in a (comparatively) reduced and / or increased influence on electromagnetic waves in these sections. For example, this makes it possible to implement reduced mirroring.

[0013] It can be provided that the substrate essentially has an upper surface (e.g. along an optical axis) and a lower surface (e.g. pointing opposite to an optical axis). In this case, for example, an optical surface can have an upper surface or vice versa. It can be provided that a substrate is processed or treated (only) on one side by the method. Alternatively, it can also be provided that at least or exactly two surfaces, for example opposing surfaces of a lens, are processed by the method. In other words, the provision, application, etching and / or removal can be carried out (only) on one (optical) surface of the substrate, preferably on both and / or all surfaces of the substrate. As a result, at least one or more zonal optical coatings can be arranged on one or more sides or surfaces of the substrate.This makes it possible to achieve (in each case) an identical or different influence on electromagnetic waves. This can also make it possible to create an optical system with at least two optical devices or substrates comprising (each at least one) optical coating or zonal optical coating.

[0014] The substrate preferably comprises at least one (zonal) optical coating. It can also be provided to arrange at least two, three, or more (zonal) optical coatings on the substrate, in particular one above the other. The (zonal) optical coatings preferably differ, in particular with regard to thickness, material, and / or (areal) dimensions. This advantageously allows the optical properties to be adapted or adjusted over a wide range.

[0015] Alternatively or additionally, it can be provided that a substrate has at least two zonal optical coatings, which are arranged adjacent to one another at least in sections (see below). This can be achieved, for example, by repeatedly applying the method.

[0016] It can be provided that the zonal optical coating at least partially covers the substrate, in particular an optical surface of the substrate. The area of ​​the zonal optical coating and / or the further zonal optical coating can comprise at least 10%, in particular at least 30%, for example at least 50%, preferably at least 70%, particularly preferably at least 85%, ideally at least 95% of the area of ​​the substrate, in particular of the (one) optical surface of the substrate.

[0017] It may be provided, particularly at the beginning of the process, to provide an optical coating on an optical surface of the substrate. The optical coating may preferably (initially) completely cover the substrate, in particular an (optical) surface of the substrate.

[0018] A mask can be designed to at least partially cover or conceal the substrate and / or the optical coating. The mask can have a stencil, a hole and / or a plurality of holes. Thus, a masked substrate can be obtained by applying the mask to the optical coating. The mask can be used to determine the locations at which the optical coating is (at least partially) removed by etching. The mask can cover the optical coating in a masked area and not cover it in an unmasked area. As a result, the optical coating in the masked area can be protected from etching and / or not attacked by the etching. As a result, the optical coating in the unmasked area can be attacked by etching.

[0019] The etching of the masked substrate can comprise dry etching, in particular sputter etching (see below). In this case, the optical coating can be removed at locations not concealed by the mask. Depending on the unmasked area, in particular substantially beneath (along an optical axis and / or an electrical potential) the unmasked area(s) of the mask, the optical coating can accordingly be removed. Preferably, the optical coating can be removed completely (along an optical axis and / or an electrical potential). In other words, at these locations, the optical coating can be removed until only the substrate or its (optical) surface remains.Alternatively or additionally, it may be provided that (in certain areas) the optical coating is only partially removed, for example in order to achieve a slight (remaining) mirroring at least in sections.

[0020] Removal of the mask from the substrate can preferably occur following etching. This allows the mask to be removed from the masked zonal coating. For example, this can be done by (mechanical) peeling, dissolving, and / or scraping. Alternatively or additionally, this can be done using a (chemical) solvent designed to dissolve the mask.

[0021] Within the scope of the invention, it may be advantageous for the optical coating, in particular a further optical coating, to have an anti-reflective coating, a mirror coating, a beam splitter, a filter, and / or a polarizer.

[0022] Accordingly, the optical coating can be configured to influence electromagnetic waves (see above). For example, the optical coating can be configured specifically to influence a certain wavelength range (e.g., ultraviolet), a polarization, and / or an angle of incidence.

[0023] It can be provided that (initially or upon provision) the optical coating covers the substrate, in particular an (optical) surface of the substrate, at least partially, preferably completely (over its entire surface). The optical coating can preferably be continuous, planar, and / or curved. It can be particularly preferred if the optical coating has a shape adapted to the shape of the substrate, in particular to the shape of the (optical) surface(s) of the substrate. Accordingly (see above), the optical coating can have a curvature, in particular be convex and / or concave (at least in sections). The optical coating can have a radius of curvature between 1 µm and 1000 m, in particular between 10 µm and 100 m, for example between 100 µm and 10 m, preferably between 1 mm and 100 cm, particularly preferably between 1 cm and 80 cm, ideally between 2 cm and 75 cm.Preferably, the optical coating can have a constant thickness. Preferably, the optical coating can be arranged uniformly on the substrate. It can also be provided that the optical coating has different (optical) thicknesses (from the perspective of light), in particular with respect to an optical axis.

[0024] It can be provided that at least two or more optical coatings are applied one above the other, whereby they can preferably be etched together through a mask. Alternatively or additionally, it is conceivable that one optical coating is first processed by arranging, applying, etching, and / or removing. Subsequently, another optical coating can be processed by arranging, applying, etching, and / or removing. Thus, at least two or more zonal optical coatings can be produced on the substrate.

[0025] Within the scope of the invention, it is conceivable that the application of a mask comprises an at least partial, in particular reversibly detachable, arrangement of the mask on or above the optical coating, wherein in particular the mask comprises a, preferably inorganic, glass.

[0026] The mask preferably comprises at least one (or more) recess(es) which are designed to form an unmasked region of the optical coating. During etching, the optical coating can be removed at these locations. Preferably, the mask or a material of the mask is designed to withstand etching and / or not be removed by etching. Accordingly, a negative of the mask can be etched into the optical coating by etching. The mask can comprise a metal, for example (stainless) steel, which is preferably insensitive, robust and / or dimensionally stable. Alternatively or additionally, the mask can comprise an (adhesive) film and / or an adhesive medium, which advantageously do not influence the etching (due to their material or their electrical properties). It can be particularly preferred if the mask comprises a, preferably inorganic, glass. The mask can comprise quartz sand orSilicon dioxide. The mask can have a (substantially) uniform thickness. The mask can have a thickness of between 1 µm and 3 mm, in particular between 10 µm and 500 µm, for example between 50 µm and 350 µm, preferably between 100 µm and 300 µm, particularly preferably between 150 µm and 250 µm, ideally between 180 µm and 220 µm. The mask can be planar and / or plate-like. It can be particularly preferred if the shape of the mask can be arranged flush with the optical coating. Accordingly, the mask can preferably be arranged uniformly on and / or on the optical coating in order to advantageously simulate its shape. This makes it possible to achieve particularly high etching accuracy. The mask can preferably be arranged on the optical coating without any gaps. This can improve accuracy and / or optimize anisotropic etching.The mask can preferably be arranged contour-true, concentrically and / or (rotationally) symmetrically, in particular with respect to an optical axis and / or relative to the optical coating or the substrate. This can increase the accuracy during etching. Preferably, the mask has few and / or no edge projections and / or overhangs at the edge. This can (further increase) the accuracy during etching, in particular a "sharp" (etching) edge of an optical coating and / or further optical coating can be achieved (no blurring of the edges). It can be provided that the mask, in particular in the edge region of the mask and / or in the region of one (or more) recesses, is designed (if possible) at right angles and / or perpendicular to the optical coating. This can result in high accuracy and / or anisotropic etching.Alternatively or additionally, the mask, particularly edges of the mask facing away from the substrate and / or the optical coating, may have a phase. This can improve the accuracy and / or uniformity of the etching.

[0027] The mask can be arranged (on top) on the substrate and / or the optical coating, in particular along an optical axis. Accordingly, for example, the substrate can form a bottom layer, the optical coating a second (overlying) layer, and / or the mask a third layer, which is arranged in particular above the optical coating and / or the substrate. Accordingly, the components can be arranged one above the other in multiple layers. (Subsequent) etching preferably takes place from above in the direction of the mask. The application of a mask to the optical coating can be done manually, for example. Preferably, the application of the mask can take place without a vacuum. The mask can, for example, be glued or sprayed on. The application of the mask can, for example, be done by photolithography. Alternatively or additionally, a mask can also be produced by vapor deposition.It can be provided that this takes place in a coating chamber, preferably in the same coating chamber as the etching. This can accelerate the process.

[0028] It can also be provided that the mask can be arranged mechanically, in particular reversibly detachably, with respect to the substrate and / or the optical coating, for example via an adjustable fastening device (e.g. a screw device). This allows a distance between the mask and the optical coating (or substrate) to be (finely) mechanically adjustable. This allows a mask to be advantageously used repeatedly and / or (physical) contact between the mask and the optical coating to be prevented (no risk of damage and / or destruction). It can also be provided that an optical coating is (mechanically) shaped by bringing the mask closer, in particular by pressing it against the substrate. This allows particularly high precision in the shaping of the optical coating to be achieved.It can also be provided that (intentionally) a gap is provided and / or adjustable between the optical coating and the mask. For example, a (defined) gap can be between 10 nm and 1 mm, in particular between 0.1 µm and 100 µm, for example between 1 µm and 10 µm, preferably between 2 µm and 8 µm, particularly preferably between 4 µm and 6 µm, ideally 5 µm. This allows a favorable compromise between accuracy and production speed to be achieved.

[0029] Within the scope of the invention, it can be provided that the etching comprises introducing into a coating chamber and / or evacuating the coating chamber.

[0030] A coating chamber can be configured to perform etching, in particular dry etching, in particular sputter etching. For this purpose, it can be provided that the (masked) substrate is introduced (e.g., manually) into the coating chamber, preferably after application of the mask and / or before etching. In this case, the coating chamber can be evacuated, preferably subsequently, to create a vacuum (e.g., using a vacuum pump). This can prevent the (disruptive) influence of molecules in the air.

[0031] It is further conceivable that the etching, in particular sputter etching, of the masked substrate in order to at least partially remove the optical coating depending on the unmasked area, an inflow of a working medium, in particular comprising helium, argon, oxygen and / or nitrogen, preferably into a coating chamber, and / or an acceleration of the working medium, in particular a plasma formed as a function of the working medium, substantially perpendicular to the mask, in particular along an electrical potential applied to the coating chamber.

[0032] In this case, it can be provided that etching, in particular sputter etching, advantageously does not damage the substrate, in particular an optical surface of the substrate, and / or other zonal optical coatings (due to the mask). In addition, roughening of the substrate can be prevented. In addition, it can be provided that cleaning is not necessary or only necessary to a reduced extent. Helium, argon, oxygen and / or nitrogen can be used as the working medium. The working medium can be used (or selected) depending on the mask, in particular the material of the mask, and / or the optical coating, in particular the material of the optical coating. Helium and / or argon can be used (as noble gases) for etching, in particular also for metals. Helium can preferably be used at least partially (e.g.10%), which advantageously prevents and / or reduces voltage flashovers and / or increases the thermal conductivity of the working gas or plasma. Oxygen and / or nitrogen (or their ions) can (also) react chemically, e.g., with the mask and / or the optical coating. This can increase the etching speed and / or enable (at least partially) isotropic etching. The working medium can be admitted into the coating chamber by flowing in (e.g., by opening a valve), in particular after evacuation (see above). Subsequently, (only) the working medium can be present in the coating chamber. Since, in particular, no photolithography is necessary, the method according to the invention can advantageously be integrated cost-effectively and / or easily into conventional optics production.

[0033] Preferably, the coating chamber comprises an anode and a cathode, which are preferably arranged at the top and bottom (or vice versa) in the coating chamber, respectively, and are preferably arranged along an optical axis and / or etching direction.

[0034] By applying a (time-varying) electrical potential (or a bias voltage) to the anode and / or cathode, the working medium can be accelerated. The electrical potential can at least partially convert the working medium into a plasma. In other words, the working medium (and / or resulting ions) can be accelerated in the direction of the cathode and / or anode, in particular along an etching direction and / or an optical axis. The substrate, the (further) optical coating and / or the mask can preferably be arranged (substantially) perpendicular to the etching direction and / or the optical axis. Preferably, the (repeated) acceleration of the working medium, or its ions and / or a resulting plasma, can at least partially remove (in particular "knock out") the (further) optical coating in unmasked areas (by material removal).The acceleration can preferably have a preferred direction, in particular along the electrical potential or between the anode and / or cathode. This can result in anisotropic etching. Preferably, the optical coating can be removed essentially in (all) unmasked areas, preferably completely. Accordingly, "depending on" in this context can include etching below or beneath the mask (or the unmasked areas), and / or along the applied (electrical) potential or perpendicular to the optical coating and / or mask. This can etch the mask, in particular a negative of the mask, into the optical coating. Preferably, the (material of the) substrate and / or one (or more) of the etching process parameters are configured so as not to damage and / or etch the substrate.The etching, in particular the speed and / or accuracy of the etching, can be controlled depending on one or more process parameters. This can include at least one or more of the following process parameters (in particular those of the etching): - temperature (in the coating chamber), which is preferably less than 50°C, in particular room temperature, - (applied) bias voltage between anode and cathode between 50 and 4000 V, preferably between 150 and 2500 V, particularly preferably between 250 and 2000 V, ideally between 750 and 1500 V, for example 1200 V, whereby preferably anisotropic etching can be optimized and / or under-etching of the mask can be avoided, wherein the bias voltage can preferably be (repeatedly) varied, - High frequency power (HF), in particular the bias voltage, between 100 to 2000 W, preferably between 150 to 1500 W, particularly preferably between 200 to 1000 W, ideally 500 W, in order to advantageously achieve a high etching rate, - Base pressure (especially after evacuation) in the coating chamber preferably of at most ≤ 4*10 -5 mbar, - Process pressure (especially when plasma is generated or has been generated and / or acceleration is carried out) between 1*10 -4 mbar to 1 mbar, preferably between 1*10 -3 mbar to 1*10 -1 mbar, particularly preferably between 0.3*10 -2 mbar to 5*10 -2 mbar, ideally ≤ 1 × 10 -2 mbar - Duration of etching between 1 and 1500 min, preferably between 4 and 300 min, particularly preferably between 15 and 200 min, ideally between 30 and 150 min, for example 60 min, preferably until the (further) optical coating is etched away down to the substrate, - Inflow of the working gas, preferably until process pressure is reached, e.g. comprising, for example, 10 sccm helium and 100 sccm (standard cubic centimeters per minute) oxygen (O2).

[0035] It is also conceivable that, before and / or during the provision of a substrate with an optical coating, the optical coating is arranged on the substrate, in particular on an optical surface of the substrate, whereby in particular the optical coating covers the substrate at least partially, preferably completely.

[0036] Within the scope of the invention, an optical coating, in particular features of an optical coating, can (in principle) apply to another optical coating and vice versa. The optical coating can be arranged on and / or on the substrate, in particular an (optical) surface of the substrate. The optical coating can comprise oxides (e.g., SiO2, HfO2, and / or Al2O3) and / or fluorides (e.g., MgF2, LaF3, and / or AlF3). The thickness of the optical coating can be a function of the wavelength, in particular specific for an application (e.g., ultraviolet light). This can achieve a particularly strong influence and / or an efficient effect of the optical coating. The thickness of the optical coating can preferably be (substantially) a quarter of the wavelength, in particular specific for an application (e.g., ultraviolet light).For example, the thickness of the optical coating can be approximately 50 nm if the application area is approximately 200 nm. The optical coating can, for example, have a thickness, in particular along an optical axis and / or (essentially) perpendicular to the substrate, of between 1 pm and 10 µm, in particular between 100 pm and 1 µm, for example between 1 nm and 200 nm, preferably between 10 nm and 100 nm, particularly preferably between 30 nm and 70 nm, ideally between 45 nm and 55 nm. The arrangement of a (further) optical coating on the substrate can be carried out by physical vapor deposition (PVD), evaporation, sputtering, and / or chemical vapor deposition (CVD), atomic layer deposition. It can be provided that at least two or more (further) optical coatings are arranged one above the other.These can be arranged one after the other by arranging them on the (further) optical coatings underneath. The total thickness of the (further) optical coatings can, for example, have a thickness, in particular along an optical axis and / or (essentially) perpendicular to the substrate, of less than 1 mm, in particular less than 100 µm, preferably less than 10 µm, particularly preferably less than 5 µm, ideally less than 1 µm. A smaller thickness can enable a faster manufacturing process and / or influence by different optical coatings with the same (total) thickness.It can be provided that the (further) optical coating in an edge region of the coating has a width between 50 μm and 10 mm, in particular between 1 μm and 5 mm, for example between 10 μm and 4 mm, preferably between 100 μm and 3 mm, particularly preferably between 150 μm and 2 mm, ideally between 200 μm and 1 mm. A wider edge region can enable faster production. A narrower edge region can enable greater precision and / or less (undesired or unpredictable) optical influences (e.g., scattering).

[0037] Within the scope of the invention, it is optionally possible for the method to comprise at least one further application, further etching and / or further removal after the removal in order to produce a further zonal optical coating, wherein preferably during a further application a further mask on the substrate produces a further masked region which at least partially, preferably completely, covers the zonal optical coating.

[0038] Accordingly, the method can be carried out at least partially a further, renewed, and / or repeated time. Accordingly, the features shown (for a first implementation) can also be provided (analogously) for a second and / or further implementation. It can preferably be provided that the further mask covers the (existing) zonal optical coating (or coatings) at least partially, preferably completely, as a result of which they are advantageously not altered by further etching. In particular, the above process parameters can be used essentially identically, in particular if the same and / or a similar (further) optical coating is used. Depending on the further optical coating, the process parameters can be adapted, in particular depending on the optical coating, to the further optical coating and / or the (further) mask.It may be particularly preferred if a further inflow and / or etching is carried out with a different working medium. For example, at least one of the following features may be provided: - a (first or lower) optical coating comprises a first material, e.g. Al2O3, which is particularly designed as a dielectric reinforcement (during operation), - has a (second or upper) further optical coating which comprises a metal, e.g. aluminium or Al, and in particular (during operation) is designed or functions as a mirror, whereby in particular the upper coating can form a reflective layer which can, for example, reflect light coming “from below” along the optical axis back into the further (“lower”) optical coating, - Applying a mask - (first) etching with a working medium, e.g. with (pure) argon and / or helium (preferably no oxygen), which can lead in particular to an intensive and / or anisotropic etching, with advantageously sharp edges or a narrow transition area, whereby in particular the metal, e.g. aluminum or Al, can be removed, - Removing the mask, - further (second) etching, e.g. with oxygen, helium, and / or nitrogen (preferably no argon), whereby preferably in areas where metal, e.g. aluminum, remains, a (protective) mask is formed by this, and advantageously in the remaining areas the underlying optical coating (e.g. Al2O3) is etched away, which can in particular lead to a sharp (etched) edge with a very narrow transition area.

[0039] It can therefore be provided that at least one (further and / or zonal) optical coating can be used at least partially as a mask, in particular for (further) etching.

[0040] Alternatively, the order of the optical coating and the further optical coating in the above example can also be reversed. Thus, corresponding substrates with specific (further) optical coatings can be provided for different optical devices or systems. It can also be provided to produce a (first) zonal optical coating using a (first) mask. Furthermore, a further (second) zonal optical coating can be produced using a further (second) mask, wherein the further zonal optical coating is preferably arranged in a different region of the structure.

[0041] Furthermore, it can be provided within the scope of the invention that the zonal optical coating and the further zonal optical coating are at least partially separated, at least partially overlap and / or completely overlap by a separation region.

[0042] Accordingly, at least two or more zonal optical coatings can be arranged on a substrate. These can be arranged next to one another or adjacent to one another, in particular spaced from one another by a separating region (without coating), flush next to one another and / or concentrically. These can be designed symmetrically, in particular with respect to an optical axis. For example, they can be rectangular, in particular square. Alternatively, they can be circular or cylindrical. This can enable particularly simple production and / or advantageous optical properties. It can be particularly preferred if the zonal optical coatings are arranged symmetrically and concentrically, wherein in particular a zonal optical coating can be arranged (flat) inside or outside another zonal optical coating.It can be provided that the separation region, in particular its one-dimensional distance between different coatings, has a width of between 1 nm and 10 mm, in particular between 100 nm and 2 mm, for example between 1 µm and 1 mm, preferably between 100 µm and 500 µm, particularly preferably between 200 µm and 400 µm, ideally between 250 µm and 350 µm. With known or classic shadow masks in the form of substrate apertures and / or PVD coating processes, adjacent zonal optical coatings can only be achieved with transition regions of a few millimeters, if at all. However, if one zone is to be enclosed by another zone, classic substrate apertures can only be supplemented by more complex adhesively bonded or sprayed-on shadow masks. Accordingly, the method used can advantageously enable simplified production.

[0043] Particularly preferably, the separation area can be larger than an edge area. This can result in improved manufacturing quality, particularly since no undesirable combination or mixing occurs between different zonal optical coatings.

[0044] With regard to the present invention, it is conceivable that the zonal optical coating, and / or in particular the further zonal optical coating, has an edge region which in particular has a width between 100 µm and 500 µm.

[0045] An edge region can be specific for a transition between coating and substrate and / or for a transition between adjacent (superimposed) coatings. For example, due to manufacturing-related reasons, this edge region may not be (infinitesimally) sharp, but at least partially blurred or smeared. This can be attributed to the etching (as such) and / or the mask, which (likewise) cannot be configured exclusively along one direction. However, the process can enable (relatively) rapid production and / or (in combination) high precision (a narrow edge region). For example, the edge region can have a width between 0.1 µm and 10 mm, in particular between 10 µm and 2 mm, for example between 50 µm and 1 mm, preferably between 100 µm and 500 µm, particularly preferably between 200 µm and 400 µm, ideally between 250 µm and 350 µm.

[0046] Furthermore, it is conceivable that the zonal optical coating and in particular the further zonal optical coating is produced on an optical surface, in particular the same optical surface, of the substrate by the, in particular further, application, etching and / or removal.

[0047] In other words, it may be particularly preferred that at least two (further) zonal optical coatings are produced on (exactly) one (optical) surface of the substrate. Accordingly, different coatings can point in the same direction, in particular with respect to an optical axis. This makes it possible to combine different and / or identical optical properties of the coatings, in particular depending on the respective arrangement. These can be arranged in the same plane, in particular directly on an optical surface of the substrate. For example, they can be produced by a method according to the invention carried out at least twice in succession, e.g. comprising arranging, providing, applying, etching and / or removing and a further arranging, further providing, further applying, further etching and / or further removing.It is also conceivable that different coatings can be arranged one above the other, at least in sections, for example by arranging a (first) optical coating and subsequently arranging a further (second) optical coating.

[0048] It is further conceivable that, in particular instead of providing, an optical coating is carried out during, during, and / or before the application of a mask, wherein preferably the optical coating is applied underneath and / or together with the mask.

[0049] It is conceivable that an optical coating is applied first. The mask can then be applied, preferably using an identical or alternative method. It is also conceivable that the optical coating is prepared together with the mask and (both) are arranged (together) on the substrate during a single application. This eliminates the need for (initial) preparation. Furthermore, the manufacturing process can be adapted and / or simplified.

[0050] The above object is achieved according to a second aspect by an optical device according to the invention, comprising a substrate, in particular having an optical surface of the substrate, and at least one zonal optical coating, in particular on the substrate, preferably on an optical surface of the substrate, which was produced by the method according to the first aspect.

[0051] In the simplest case, a substrate, e.g., in the form of a lens, can be used. The optical device can comprise at least one substrate, preferably at least two or more substrates, which can be arranged one after the other, in particular, along an optical axis. As a result, one (or each) substrate, in particular its optical surface and / or zonal optical coating, can influence electromagnetic radiation (essentially) traveling along the optical axis, e.g., by focusing, scattering, transmitting, and / or reflecting it.

[0052] It can be provided (for an optical device) that an upper substrate, comprising a zonal optical coating, has a mirror coating which reflects back electromagnetic radiation incident in particular from below. In addition, it can be provided that the upper substrate has a further zonal optical coating arranged below the zonal optical coating, which is preferably designed as an anti-reflective coating. Accordingly, electromagnetic radiation incident from below can penetrate the upper substrate and / or the further zonal optical coating and then be reflected (downward) by the zonal optical coating. The zonal optical coating and / or further zonal optical coating can have a hole, in particular a central hole, which can preferably be produced by etching and / or further etching.It can preferably be provided that an optical device comprises such an upper substrate (described above) and additionally a lower substrate, in particular one arranged oppositely (or aligned) and (otherwise) identically configured. In other words, this can result in a (virtually) resonator in which electromagnetic waves are (repeatedly) reflected between the upper and lower substrates and / or can penetrate and / or exit through a respective hole.

[0053] This results in the same advantages with respect to an optical device according to the invention according to the second aspect as have already been described with respect to a method according to the invention according to the first aspect.

[0054] Within the scope of the invention, it may be advantageous for the substrate, particularly on an optical surface of the substrate, to have a further zonal optical coating. Accordingly, an optical device may comprise at least one substrate with at least two zonal optical coatings. This may result in a high degree of design freedom for the optical properties.

[0055] Further advantages, features, and details of the invention will become apparent from the following description, in which several embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. These schematically show: Fig. 1 a substrate Fig. 2 a substrate with curvature Fig. 3 a zonal optical coating and another zonal optical coating Fig. 4 a procedure.

[0056] In the following figures, identical reference numerals are used for the same technical features, even for different embodiments.

[0057] Fig. 1 shows a substrate 10, in particular with an optical surface 10.1 of the substrate 10, on which an optical coating 20 is arranged. This coating can initially be continuous. A mask 30 and / or a further mask 30.1 can be arranged on the optical coating (for example, parallel and / or spaced apart), preferably by application 120. This mask can have recesses or holes. A working medium 50, in particular a plasma 51, can perform an etching 130 through these, whereby the optical coating 20 is preferably removed ("etched away") at least partially, in particular in an unmasked region 22. For this purpose, in particular after the application 120 of a mask 30, the masked substrate 11, which for example has a masked region 21 (or further masked region 21.1) and an unmasked region 22, can be arranged in a coating chamber 40.By applying an electrical potential to the anode and / or cathode (not shown), which can be arranged, for example, at the top and bottom of the coating chamber 40, the working medium 50, or a resulting plasma 51, can be moved along the electrical potential, here from top to bottom (or vice versa) (see, for example, the arrows shown). The middle arrow can also represent, for example, an optical axis, which in the present case (and for example) is arranged in the same direction. By etching 120, the optical coating 20 of the masked substrate 11 can be removed in unmasked regions 22, in particular to obtain a masked zonal coating 23. By removing 140 the mask 30, a zonal optical coating 24 can be obtained. Different parts of the zonal optical coating 24 can have a separation region 25.Furthermore, an edge region 26 is shown by way of example, in which a transition between the zonal optical coating 24 and the substrate 10, in particular an optical surface 10.1 of the substrate 10, can be arranged.

[0058] Fig. 2 shows (based on Fig. 1) by way of example, a substrate 10 with an optical surface 10.1, which in particular has a curvature. In this case, the central region can have a greater thickness than the edge region and / or be designed (rotationally) symmetrically with respect to an optical axis 1. Accordingly, an optical coating 20 (not shown), a further optical coating 20.1, a mask 30, a further mask 30.1, a masked region 21, a further masked region 21.1, an unmasked region 22, a masked zonal coating 23, a zonal optical coating 24, and / or a further zonal optical coating 24.1 can also have a (corresponding or adapted) curvature.

[0059] Fig. 3 shows a substrate 10, in particular an optical surface 10.1 of a substrate 10.1, in a plan view (from above). By way of example, a zonal optical coating 24 and another zonal optical coating 24.1 are arranged, which can be produced in particular by a method according to the invention, in particular by repeatedly performing the method.

[0060] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged next to each other at a distance, in particular separated by a separation region 25 (for example top left in Fig. 3). The zonal optical coating 24 and / or the further zonal optical coating 24.1 (each) may have an edge region 26 and / or a further edge region 26.1.

[0061] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged flush next to each other (for example in the middle at the top in Fig. 3). This allows the respective boundary areas to overlap, in particular to (partially) combine their properties.

[0062] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged next to each other in an overlapping manner (for example top right in Fig. 3). This allows the optical properties or influence of electromagnetic waves to be combined in the overlapping area, for example, filtering and reflection.

[0063] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged one inside the other and / or concentrically spaced, in particular separated by a separation region 25 (for example bottom left in Fig. 3). This allows electromagnetic waves in the inner region to be influenced, e.g., filtered, by the additional zonal optical coating 24.1, and reflected, e.g., by the zonal optical coating 24 in the outer region. The separation region may exhibit no influence and / or enable a smooth transition.

[0064] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged one inside the other and / or concentrically flush, in particular not separated by a separating region 25 (for example, centrally at the bottom in Fig. 3). As a result, electromagnetic waves in the inner region can be influenced, e.g., filtered, by the additional zonal optical coating 24.1, and reflected, e.g., by the zonal optical coating 24 in the outer region.

[0065] In this case, a zonal optical coating 24 and a further zonal optical coating 24.1 can be arranged concentrically and / or overlapping (for example bottom right in Fig. 3). This allows electromagnetic waves in the inner region to be influenced by the additional zonal optical coating 24.1, e.g., partially reflected, and (additionally) polarized by the zonal optical coating 24 in the inner and outer regions. This allows the optical properties to be combined.

[0066] Fig. 4 shows a method for producing a zonal optical coating 24 on a substrate 10, in particular an optical surface 10.1 of the substrate 10, comprising - Providing 110 a substrate 10 which is non-planar on at least one side and has an optical coating 20, - applying 120 a mask 30 on the optical coating 20 to obtain a masked substrate 11, wherein the mask 30 covers the optical coating 20 in a masked area 21 and does not cover it in an unmasked area 22, - etching 130 the masked substrate 11 to at least partially remove the optical coating 20 in dependence on the unmasked region 22, thereby producing a masked zonal coating 23, - Removing 140 the mask from the masked zonal coating 23 to obtain a zonal optical coating 24.

[0067] It can be provided that before and / or during the provision 110 of a substrate 10 with an optical coating 20, an arrangement 105 of the optical coating 20 is carried out on the substrate 10, in particular an optical surface 10.1 of the substrate 10, whereby in particular the optical coating 20 covers the substrate 10 at least partially, preferably completely.

[0068] It can be provided that the application 120 of a mask 30 comprises an at least partial, in particular reversibly detachable, arrangement 121 of the mask 30 on or above the optical coating 20, wherein in particular the mask 30 comprises a, preferably inorganic, glass.

[0069] In addition, it can be provided that the etching 130 comprises an introduction 131 into a coating chamber 40 and / or an evacuation 132 of the coating chamber 40.

[0070] It is further conceivable that the etching 130, in particular a sputter etching 130, of the masked substrate 11, in order to at least partially remove the optical coating 20 depending on the unmasked area 22, an inflow 133 of a working medium 50, in particular comprising helium, argon, oxygen and / or nitrogen, preferably into a coating chamber 40, and / or an acceleration 134 of the working medium 50, in particular of a plasma 51 formed as a function of the working medium 50, substantially perpendicular to the mask 30, in particular along an electrical potential applied to the coating chamber 40.

[0071] It can be provided that the method comprises, after the removal 140, at least one further application 150, further etching 160 and / or further removal 170 in order to produce a further zonal optical coating 24.1, wherein preferably during a further application 150 a further mask 30.1 on the substrate 10 produces a further masked region 21.1 which at least partially, preferably completely, covers the zonal optical coating 24.

[0072] It may be particularly preferred that the zonal optical coating 24, and in particular the further zonal optical coating 24.1, is produced on an optical surface 10.1, in particular the same optical surface 10.1, of the substrate 10, by the, in particular further application 120, 150, etching 130, 160 and / or removal 140, 170. List of reference symbols 1 optical axis 10 Substrat 10.1 optical surface of the substrate 11 masked substrate 20 optical coating 20.1 further optical coating 21 masked area 21.1 further masked area 22 unmasked area 23 masked zonal coating 24 zonal optical coating 24.1 further zonal optical coating 25 Separation area 26 Marginal area 26.1 further peripheral area 30 Mask 30.1 additional mask 40 coating chamber 50 Working medium 51 Plasma 105 Applying the optical coating to the substrate 110 Providing a substrate 24 with an optical coating 120 Applying a mask to the optical coating 121 Placing the mask on or over the coating 130 Etching, in particular sputter etching, of the masked substrate 131 Placement in a coating chamber 132 Evacuating the coating chamber 133 Inflow of a working gas 134 Acceleration of the working medium, in particular a plasma 140 Removing the mask 150 further applications 160 further etchings 170 further removal

Claims

[1] Method for producing a zonal optical coating (24) on a substrate (10), in particular an optical surface (10.1) of the substrate (10), comprising - providing (110) a substrate (10) which is non-planar on at least one side and has an optical coating (20), - applying (120) a mask (30) on the optical coating (20) to obtain a masked substrate (11), wherein the mask (30) covers the optical coating (20) in a masked area (21) and does not cover it in an unmasked area (22), - etching (130) the masked substrate (11) to at least partially remove the optical coating (20) depending on the unmasked area (22), thereby producing a masked zonal coating (23), - removing (140) the mask from the masked zonal coating (23) to obtain a zonal optical coating (24). [2] Method according to claim 1, characterized by that the optical coating (20), in particular a further optical coating (20.1), has an anti-reflection coating, a mirror coating, a beam splitter, a filter and / or a polarizer. [3] Method according to claim 1 or 2, characterized by that the application (120) of a mask (30) comprises an at least partial, in particular reversibly detachable, arrangement (121) of the mask (30) on or above the optical coating (20), wherein in particular the mask (30) comprises a, preferably inorganic, glass. [4] Method according to one of the preceding claims, characterized by that the etching (130) comprises introducing (131) into a coating chamber (40) and / or evacuating (132) the coating chamber (40). [5] Method according to one of the preceding claims, characterized by , that the etching (130), in particular a sputter etching (130), of the masked substrate (11) in order to at least partially remove the optical coating (20) depending on the unmasked area (22), an inflow (133) of a working medium (50), in particular comprising helium, argon, oxygen and / or nitrogen, preferably into a coating chamber (40), and / or an acceleration (134) of the working medium (50), in particular a plasma (51) formed as a function of the working medium (50), substantially perpendicular to the mask (30), in particular along an electrical potential applied to the coating chamber (40). [6] Method according to one of the preceding claims, characterized bythat before and / or during the provision (110) of a substrate (10) with an optical coating (20), an arrangement (105) of the optical coating (20) on the substrate (10), in particular an optical surface (10.1) of the substrate (10), is carried out, whereby in particular the optical coating (20) covers the substrate (10) at least partially, preferably completely. [7] Method according to one of the preceding claims, characterized by that the method comprises, after the removal (140), at least one further application (150), further etching (160) and / or further removal (170) in order to produce a further zonal optical coating (24.1), wherein preferably during a further application (150) a further mask (30.1) on the substrate (10) produces a further masked region (21.1) which at least partially, preferably completely, covers the zonal optical coating (24). [8] Method according to the preceding claim, characterized by that the zonal optical coating (24) and the further zonal optical coating (24.1) are at least partially separated, at least partially overlap and / or completely overlap by a separation region (25). [9] Method according to one of the preceding claims, characterized by that the zonal optical coating (24), and / or in particular the further zonal optical coating (24.1), has an edge region (26, 26.1) which in particular has a width between 100 µm and 500 µm. [10] Method according to one of the preceding claims, characterized bythat the zonal optical coating (24), and in particular the further zonal optical coating (24.1), is produced on an optical surface (10.1), in particular the same optical surface (10.1), of the substrate (10), by the, in particular further application (120, 150), etching (130, 160) and / or removal (140, 170). [11] Method according to one of the preceding claims, characterized by that, in particular instead of providing (110), an optical coating (20) is carried out during and / or before the application (120) of a mask (30), wherein preferably the optical coating (20) is applied underneath and / or together with the mask (30). [12] Optical device comprising a substrate (10), in particular having an optical surface (10.1) of the substrate (10), and at least one zonal optical coating (24) which was produced by the method according to one of the preceding claims. [13] Optical device according to the preceding claim, characterized by that the substrate (10), in particular on an optical surface (10.1) of the substrate (10), has a further zonal optical coating (24.1).

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