EP1910096B1 - Marked member made of transparent material and method of manufacture - Google Patents

Description

The laying invention relates to a body of transparent material having the features of the preamble of claim 1.

It may be desired for various reasons to provide such bodies with markings which should be recognizable at least under certain circumstances and with the aid of suitable devices. For example, the markings may have the purpose of indicating a particular origin of the body. In this context, such markers are also referred to as counterfeit protection. However, the markers can also have an artistic purpose, for example, in the form of appealing graphics.

So far, such markers were usually generated by laser ablation or by mechanical or chemical action on the transparent material. Such markings have the disadvantage that they are constantly visible and thus influence the appearance of the body. Furthermore, it has been difficult to produce multicolor markers. In order to make the markers multicolored, different chemical compounds had to be introduced into the marking for each individual color. In order to produce the multicolored impression, it was then necessary to use illumination sources which emit electromagnetic radiation of different wavelengths, wherein each wavelength had to be adapted to one of the chemical compounds used.

The WO 97/03846 A1 shows a method for invisibly marking a diamond. The markings are perceptible by means of dark microscopy or an interference microscope.

A generic body goes out of the GB 2 383 012 A out.

The object of the invention is to provide a body of transparent material with a marker, which on the one hand affects the visual appearance of the body only under certain conditions and also in a simple manner spatially and color highly resolved feasible.

This object is achieved by a body having the features of claim 1.

Nanoparticles are nanoscale particles (that is, their dimensions are in the nanometer range). In the context of the present application, the term nanoparticles is understood to mean a particle which, due to its dimensions, essentially does not scatter any electromagnetic radiation in the visible spectral range. In order for the scattering of electromagnetic radiation to be negligible, the dimensions of the particle should be less than about 1/10, preferably less than 1/20 of the wavelength of the electromagnetic radiation. With respect to the shortest wavelength in the visible spectral range (blue) of about 400 nm, this results in an upper limit for the diameter of about 40 nm, preferably about 20 nm.

In extreme cases, these nanoparticles have dimensions of only a few atomic diameters and thus consist of only a few 10 to 1000 atoms or molecules. The use of nanoparticles is of great importance for the achievement of the object according to the invention for various reasons:

On the one hand, nanoparticles do not scatter light in the visible spectral range due to their small size.

On the other hand, the nanoparticles can be formed such that they emit electromagnetic radiation in the visible spectral range when illuminated with electromagnetic radiation whose wavelength is in the non-visible spectral range. For example, the nanoparticles can be designed such that they convert higher-energy electromagnetic radiation, such as ultraviolet radiation (UV), into low-energy electromagnetic radiation in the visible spectral range, ie light. In other words, photoexcitation can be achieved by means of non-visible electromagnetic radiation, for example in the near UV range or in the infra-red (IR) range. Likewise, excitation by a combination of UV and IR radiation would be possible.

When using certain nanoparticles (for example those made of semiconductor materials, which are also known as semiconductor quantum dots) causes the small dimensioning that quantum effects play a role, which cause a low emission bandwidth of the emitted radiation. This leads to a high color saturation of the emitted light.

Furthermore, the strong spatial constraint can also result in an increase in energy conversion efficiency (quantum efficiency).

By itself, the transparency of the nanoparticles in daylight, ie without additional photo-excitation, only affected by a slight residual absorption of electromagnetic radiation in the visible spectral range (basic color). The UV content in indirect daylight lighting is comparatively low, however. This residual absorption can be minimized by selecting nanoparticles whose absorption maxima are in the non-visible spectral range, preferably in the ultraviolet range. Additionally or alternatively, the energy gap between the maximum of the absorption and the maximum of the emission in the luminescence spectrum for the same electronic transition can be increased with the aid of the Stokes shift. Since the Stokes shift in nanoparticles can be greater than that of macroscopic particles, the residual absorption in the visible spectral range and thus the basic color can be further greatly reduced or eliminated altogether.

However, there are also nanoparticles in which absorption and emission take place decoupled from one another and are thus far away from each other in spectrums (for example FRET).

Another advantage of nanoparticles is the tunability of the emitted wavelength by changing the particle size. For example, on the particle size, the aspect ratio or the particle surface with the same nanoparticle material, so with the same chemical conditions, a large wavelength range of the emitted light (and thus the associated Color impression) are generated, and this with the use of only one excitation wavelength. Furthermore, the wavelength of the emitted light can be controlled by the geometry of the nanoparticles having only a few atoms or molecules.

It can thus be provided in an advantageous embodiment of the invention that a first group of nanoparticles is designed such that they emit visible electromagnetic radiation having a first spectral color when illuminated with electromagnetic radiation having a wavelength in the non-visible spectral range and that a second group of nanoparticles is designed so that they are visible electromagnetic when illuminated with the same non-visible electromagnetic radiation Emit radiation having a second spectral color that is different from the first spectral color.

Since a very large part of the color spectrum can be realized via an additively weighted combination of at least three colors (for example RGB model), a further advantageous embodiment of the invention provides that a first group of nanoparticles is designed such that it emits red light a second group of nanoparticles is adapted to emit green light and a third group of nanoparticles is formed to emit blue light.

It is inventively provided to embed the nanoparticles in a matrix, wherein the resulting refractive index of the matrix (of course in the optical spectral range) is substantially equal to the refractive index of the transparent material. This measure enables a simple application of the nanoparticles (or the matrix doped with nanoparticles) without impairing the optical quality of the transparent body. For example, thermosetting resins can be used as the matrix material. Nanoparticle-doped matrices are already commercially available. A source of supply is, for example, the firm Evident Technologies, USA (http://www.evidenttech.com). In order to reduce the basic coloration described at the outset, it is possible to suitably determine the optical density of the doped matrix, for example via the doping or the Layer thickness, reduce.

The invention provides that the marking comprises microholes formed in the transparent material, in which the nanoparticles are located. By forming the diameter of the microholes sufficiently little, the light scattering cross section of the microholes can be reduced. Furthermore, the light scattering cross section can be further reduced by avoiding edges, ie by forming round microholes. The viscosity of the matrix provided with the nanoparticles can be adjusted to the selected dimensioning of the microholes and the material parameters of the transparent medium in order to ensure a wetting filling of the holes with the doped matrix. A particular advantage of the production of the marking by means of microholes lies in the fact that markings on non-planar (ie curved) surfaces can be realized in a particularly simple manner. Although markers according to the invention can also be realized on curved surfaces by other production methods (for example lithography or imprint technology), This is associated with such manufacturing process with a much greater effort.

It is inventively provided that the diameter is between 50-10 ^-6 m and 5-10 ^-6 m. This would correspond to an assumed viewing distance of about 0.2 m of an angular size of 1 arc minute and thus be below the resolution limit of the human eye.

In principle, it can be provided that a marking comprises a plurality of approximately regularly arranged microholes. In this case, it can advantageously be provided that the microholes are arranged at different distances from one another to avoid diffraction effects.

The microholes can generally be produced by various methods known in the art. It would be conceivable, for example, to stamp the microholes in the transparent material of the body (nano- or micro-imprint technology) as it is already used today in the production of CDs. Likewise, a generation by photo-structuring, z. B. possible by dry etching. Another suitable method is to create the microholes by laser bombardment (eg laser ablation) of the transparent material of the body.

In order to produce microholes in the interior of the transparent material of the body, provision may be made, for example, for the body to comprise at least two layers of transparent material which are arranged on one another, preferably adhesively bonded to one another in a transparent manner. This embodiment of the invention has the further advantage that it allows a spatially coded color information in a simple manner. For example, it can be provided that the first of the at least two layers has nanoparticles that can emit a first spectral color, and that the second of the at least two layers can have nanoparticles that emit a second spectral color. The color addition required, for example, in the RGB model can be achieved by arranging the differently colored nanoparticles of the at least two layers along the surface normals of the layers substantially one above the other.

A comparable method, in which the gray level of a color component is defined by the number (volume) of the color pigments, is the continuous tone method. Although this method has been used for many decades, it can still be used today for sophisticated image reproduction by the modern half-tone techniques (such as those used in inkjet printers) are not replaced.

Of course, regardless of the formation of the body of individual layers, even in a monolithic body, color coding could be differently colored by arrangement emissive nanoparticles in the same or adjacent microholes.

In a particularly preferred embodiment of the invention it is provided that the marking is made up of individual pixels, each pixel having at least one micro hole. This allows a systematic construction of the marker (s). In this case, it can of course be provided that at least one of the pixels comprises at least two microholes, wherein in a first of the at least two micro-holes nanoparticles are arranged, which can emit a first spectral color, and in a second of the at least two micro-holes nanoparticles are arranged can emit a second spectral color different from the first spectral color. It can also be provided that the individual pixels are arranged at different distances from one another to avoid diffraction effects.

The body of transparent material may be, for example, a body of glass or plastic.

The following describes how a multi-colored marking of a glass body can be produced. However, it will be readily apparent to those skilled in the art that the technique described below is not limited to vitreous, but may be used with other bodies of transparent material, such as plastic.

A very large part of the color spectrum can be realized via an additively weighted combination of at least three colors (for example RGB model). The weighting can be used to take into account the spectral perception of brightness for daytime and nighttime viewing. One possibility now is to code one color information per half of a glass. The third color information is placed in an intermediate layer. This can be z. B. be another thin glass plate. However, the information can also be in a nanoparticle-doped matrix layer with a thickness of a few micrometers (μm). This is z. B. applied via a spray process, the spatial coding can, for. B. via a mask.

In principle, these color layers can also be realized with the known production methods, such as inkjet printers, screen printing, lithography.

However, a particularly advantageous method will be described below. This method offers a possibility for the production of a transparent, high-resolution planar structure, which is preferably planar, but can also be curved and which emits color-fast under non-visible excitation. The body comprises at least two layers of transparent material. For example, the at least two layers of transparent material may be joined to transparent UV adhesive, wherein the refractive index of the UV adhesive is matched to that of the transparent material of the body. This has the effect that any remaining low light scattering disappears at the edges of the doped matrix layer.

The high spatial resolution is achieved here by means of microholes. Each microhole has a diameter which is below the resolution limit of the eye (below 50 x 10 ^-6 m at 200 mm distance or 1 arc minute). The microholes are filled with a nanoparticle-doped matrix. For example, one level may correspond to one of the three RGB colors. The respective weighting in one location is determined by the volume of the microhole. It can be coded in 2 dimensions, namely over the area and over the depth of the micro hole. However, a minimum depth should be maintained, which depends, for example, on the waviness of the glass. The maximum depth depends inter alia on the optical density of the doped matrix (for a dense matrix, a depth of about one wavelength may be sufficient). When coding the logarithmic brightness perception of the eye can be considered. For photo quality a dynamic range of at least 100 would be necessary, for slide quality about 1000 ( JD Foley et al. Foundations of Computer Graphics, Chapter 11: Achromatic and Colored Light. 1st edition. Addison-Wesley, 1994 ). The minimum intensity graduation should not fall below 64 levels (6-bit), at 512 levels (9-bit), the dynamic range between photo and slide.

With the addition of another thin glass plate z. For example, RGB or four colors (for example, an extra channel for colors outside the color triangle, or for higher CRI values) can be expanded with consistent resolution.

Undesired reabsorption of the emitted visible light of one color layer by another could be prevented by an appropriate choice of the color layer sequence. That is, from the viewer's point of view, the shortest wavelength color layer follows first, followed by the second shortest wavelength color layer and so on. In the RGB model, this would be the following Sequence means: first, the blue-emitting color layer, followed by the green-emitting color layer and finally the red-emitting color layer.

Preferably, it is excited from both sides (with one or more excitation sources, for example UV LED chip (s)), directly or indirectly (via reflection, total reflection, refraction).

With optically dense layers and low excitation intensity, the possible disturbance absorption can also be taken into account mathematically.

If a layer is applied by means of a spray process (mask, screen printing process), the weighting or the brightness can be determined by screening, for example taking into account the error diffusion (see Floyd and Steinberg, Adaptive Algorithm for Spatial Gray Scale, Society for Information Display 1975, Symposia Digest of Technical Papers 1975, page 36 ). When using only one mask with z. B. 10 x 10 holes (d = 5 x 10 ^-6 m) results in a dynamic range equal to 100 wherein the value for the dynamic range corresponds approximately to photo quality, but the intensity levels can already be perceived by the eye.

In this mask technique, the color quality can be further increased by using a plurality of mask-specific color systems.

Another method of applying spatially coded color information is lithography. The nanoparticles are in this embodiment in a UV-curable matrix. The few micrometers thin layer of nanoparticle-doped matrix is covered by a mask. Only those layer areas are cured which are UV-transparent in the mask. The excess matrix material can be removed carefully. This method is particularly suitable for large-area markings with a lower requirement for color-spatial coding. For example, single-color fonts, patterns or transparent segment displays can be produced on or in a transparent medium (eg glass) in this way.

It would also be conceivable to pre-structurize by simply structurable chemical compounds to which specific surface-prepared nanoparticles then adhere or which nanoparticles specifically surface-prepared for this purpose are avoided. Another possibility would be photolithographic structuring, as used in semiconductor technology.

In general, a body according to the invention of particularly high optical quality results if it is provided that the body is free of structures which absorb or scatter electromagnetic radiation in the visible spectral range.

• Erzeugung der Mikrolöcher im transparenten Material des Körpers
• Einbringung der Nanopartikel in die Mikrolöcher.

A method for producing a body according to the embodiments of the invention, in which the marking comprises microholes, comprises at least the following steps:

• Generation of microholes in the transparent material of the body
• Introduction of the nanoparticles into the microholes.

As already described, the microholes can be stamped, for example, into the transparent material, produced by laser bombardment of the transparent material or by dry etching.

A particularly simple embodiment of the second method step results if it is provided that the matrix doped with nanoparticles is first applied over a large area to the surface of the body, for example sprayed on. In this case, can be dispensed with a targeted application of the matrix in the microholes. This embodiment avoids the problem of having to apply the doped matrix with pinpoint accuracy to the surface.

However, it can also be provided that the matrix provided with nanoparticles is printed on the surface of the body with an inkjet printer. This can be done either over a large area or in a targeted manner with pinpoint accuracy.

In a particularly preferred embodiment of the invention it is provided that the matrix consists of a curable material. For example, it is possible to choose a substance that cures on UV irradiation.

This makes it possible to cure the matrix after application to the surface of the transparent body in the region of each micro-hole. This can be done without the UV radiation being deliberately used only in the area of each micro-hole. For example, can be provided to irradiate the body from the side which faces away from the surface carrying the micro-holes. It can be provided, for example, to apply a layer which is reflective in a certain UV range (which is transparent in the visible spectral range) to the surface of the body in which the microholes are produced, even before the microholes are generated. Since the UV-reflecting layer is removed in the area of the microholes when the microholes are formed, it exclusively prevents the penetration of UV radiation into the parts of the matrix which are located on the body outside the area of the microholes.

Another possibility is to precisely cure the matrix located in the microholes by means of UV lasers.

Furthermore, as an additional measure, the application of a non-stick coating for the doped matrix (which is transparent in the visible spectral range) may be provided. Such a non-stick coating reduces the adhesion between the part of the matrix which is outside the microholes, which makes it easier to remove that part.

In a further variant, it can be provided that, after application of the matrix and before curing, a stable or flexible material is placed on the coated surface and pressed, the material having a plurality of preferably continuous pores. The surface tension of the material and the diameter of the pores is to be chosen such that no capillary effect impinges, otherwise material would be sucked out of the microholes. The plurality of pores form channels into which the excess matrix located on the surface of the material can penetrate. After curing, the material can be easily removed together with the invaded matrix.

It could be in the described, provided with pores material on the one hand to a solid material, which is available again after cleaning or to a thin, flexible membrane, which is disposed of after a single use.

Particularly preferably, it can be provided that the pores do not extend in the direction of the surface normal of the surface but obliquely thereto. This results in an advantageous geometric shading effect, which causes at most a small part of the matrix located in the channels to harden in the region of the micropores. Furthermore, will by an inclination of the pores when removing the material achieves its knife action when the layer is first moved laterally before lifting from the surface.

Fig. 1a, 1b

in schematischer Darstellung ein erstes und ein zweites Ausführungsbeispiel eines erfindungsgemäßen Körpers,

Fig. 2

in schematischer Darstellung ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Körpers,

Fig. 3a, 3b

Detaildarstellungen des in Fig. 2 dargestellten Körpers

Fig. 4a-4f

ein erstes Ausführungsbeispiel eines erfindungsgemäßen Verfahrens zur Herstellung eines erfindungsgemäßen Körpers,

Fig. 5a-5e

ein zweites Ausführungsbeispiel eines erfindungsgemäßen Verfahrens zur Herstellung eines erfindungsgemäßen Körpers und

Fig. 6a-6e

ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Verfahrens zur Herstellung eines erfindungsgemäßen Körpers.

Further advantages and details of the invention will become apparent from the following figures and the description of the figures. Showing:

Fig. 1a, 1b

a schematic representation of a first and a second embodiment of a body according to the invention,

Fig. 2

a schematic representation of another embodiment of a body according to the invention,

Fig. 3a, 3b

Details of the in Fig. 2 represented body

Fig. 4a-4f

A first embodiment of a method according to the invention for producing a body according to the invention,

Fig. 5a-5e

A second embodiment of a method according to the invention for producing a body according to the invention and

Fig. 6a-6e

a further embodiment of a method according to the invention for producing a body according to the invention.

Fig. 1a schematically shows an embodiment of a body according to the invention 1 of transparent material, on the surface 2 a marker 3 is arranged in the form of an artistic representation. This marker 3 is visible only when irradiated by electromagnetic radiation in a non-visible spectral range. The source required for this is in Fig. 1a not shown. Without the irradiation, the viewer has the impression of a transparent body 1, which has no mark 3. Fig. 1b shows a further embodiment of a body 1 according to the invention in the form of a cylinder, wherein the marking 3 on the curved lateral surface (surface 2) of the cylinder is arranged.

Fig. 2 shows a further embodiment of a body 1 according to the invention, which consists of two layers 4, 5, which are interconnected via an adhesive layer 6. Inside the body 1 a realized in this embodiment as a writing mark 3 is arranged. Also in this embodiment, the mark 3 is visible only when irradiated by an electromagnetic radiation having a wavelength in the non-visible spectral range.

Fig. 3a shows a first detail of the in Fig. 2 It can be seen that the nanoparticle-doped matrix 9 is arranged in microholes 8 in each of the two layers 4, 5. Each of the dashed areas 7 represents a pixel of the mark 3. The adhesive used here for the layer 6 is permeable to the exciting wavelength. In the variant after Fig. 3a two different colors are realized, wherein in one layer 4 only nanoparticles of a first color are arranged and in the other layer 5 only nanoparticles of a different color are arranged. A three-color variant 10 is in the Fig. 3b which shows an alternative embodiment of the in Fig. 2 shown body in the region of the mark 3 shows. The third color has been sprayed on the layer 4 in this embodiment using a mask. Thereafter, the two layers 4, 5 were interconnected by the layer 6 transparent.

In the Fig. 4a-fi St a first embodiment of an inventive method for producing a body 1 according to the invention shown. It can - as in Fig. 1 shown - be provided to form the mark 3 shown on the surface 2 of the body 1. Alternatively, it can also be provided, a first layer 4 and a second layer 5 after in the Fig. 4a-f and to connect these together by an adhesive layer 6, as shown in Fig. 2 is shown.

Fig. 4a shows the initial state of the process, in which on the body 1 optionally a thin UV-reflecting layer 12, which is transparent in the visible spectral range, has been applied. Likewise, optionally, a layer 13 was applied, which represents a non-stick coating for the matrix 9 doped with nanoparticles. As in Fig. 4b 1, the microholes 8 are first generated. As a result, of course, both the layer 12 and the layer 13 in the region of the microholes 8 are removed. As a next step ( Fig. 4c ), the nanoparticle-doped matrix 9 is applied to the surface of the body 1. This can be done either by spraying, dipping or by greasing, for example. This results in the in Fig. 4c illustrated state in which the micro-holes 8 are filled and a part of the material of the matrix 9 remains on the surface of the body 1. Advantageously, it can be provided that the body 1 in the in Fig. 4c state is exposed to a vacuum for some time. As a result, any remaining in the micro holes 8 air bubbles can evaporate. The next step is done as in Fig. 4d Curing of the matrix 9 in the region of the microholes 8. This is done in this embodiment by irradiation with UV radiation from the side of the body 1 facing away from the surface provided with microholes 8. The curing of the matrix 9, which is restricted primarily to the areas of the microholes 8, is reinforced in the embodiment shown by the additional measure of the layer 12, which reflects the UV radiation away from the matrix 9 everywhere except in the area of the microholes 8. If a matrix 9 is used, which cures poorly upon contact with oxygen, this process can take place in an atmosphere of pure oxygen. As in Fig. 4e shown, the remainder of the uncured matrix material 9 can be removed by a slider. Subsequently, a post-curing of the matrix material 9 in the region of the surfaces of the microholes 8 take place. This can be done, for example, in a nitrogen atmosphere, if a matrix is used, which preferably hardens on contact with nitrogen.

The embodiment of the Fig. 5a-e is different from that after the Fig. 4a-f only in that an additional layer 14 is used, which is provided with a plurality of pores 15 formed by channels. As shown, these channels may also be formed as slanted pores 16. Is recognizable in particular in Fig. 5c in that the oblique pores 16 have the advantage that a smaller part of the material of the matrix 9 cures. This is only the part that can be achieved geometrically by UV radiation and by scattering. In the case of straight pores 15, it may happen that the entire material of the matrix 9 that has penetrated into the pores 15 in the area of the microholes 8 cures. As in Fig. 5d shown, the inclined pores 16 additionally have the advantage of a knife action, if it is provided during the removal of the layer 14, these first laterally along the body 1 and then only from the body 1 to move away.

In a further embodiment of the Fig. 6a-e the only difference to that in the Fig. 5a-e illustrated method in that in the Fig. 6a-e instead of a stiff layer 14, a flexible layer 14 was used. This could, for example, be a membrane to be used once.

Claims (25)

1. A body (1) of transparent material, wherein the body (1) has at least one marking (3) including nanoparticles, wherein the marking (3) is arranged in the transparent material and is such that, upon illumination with electromagnetic radiation whose wavelength is in the visible spectral range, it is invisible and, upon illumination with electromagnetic radiation whose wavelength is in the non-visible spectral range, it is visible, characterized in that the marking (3) is formed by way of microholes (8) with a diameter of less than 5.10^-5 m and larger than 5.10^-6 m, wherein the nanoparticles are in the microholes (8) and wherein the nanoparticles are embedded in substantially agglomeration-free manner in a matrix (9) whose resulting refractive index is substantially equal to the refractive index of the transparent material.
2. A body as set forth in claim 1, characterized in that the nanoparticles are such that, upon illumination with electromagnetic radiation whose wavelength is in the non-visible spectral range, they emit electromagnetic radiation in the visible spectral range.
3. A body as set forth in claim 2, characterized in that a first group of nanoparticles is such that upon illumination with electromagnetic radiation with a wavelength in the non-visible spectral range, they emit visible electromagnetic radiation with a first spectral color and a second group of nanoparticles is such that, upon illumination with the same non-visible electromagnetic radiation, they emit visible electromagnetic radiation with a second spectral color which is different from the first spectral color.
4. A body as set forth in claim 3, characterized in that

   - a first group of nanoparticles is such that it can emit red light,

   - a seoond group of nanoparticles is such that it can emit green light, and

   - a third group of nanoparticles is such that it can emit blue light.
5. A body as set forth in one of claims 1 through 4, characterized in that the microholes (8) are approximately regularly arranged.
6. A body as set forth in claim 5, characterized in that the microholes (3) are arranged at different spacing relative to each other to avoid diffraction effects.
7. A body as set forth in one of claims 1 through 6, characterized in that the body (1) includes at least two layers (4, 5) of transparent material which are arranged one upon the other- preferably glued to each other.
8. A body as set forth in claim 7, characterized in that the first of the at least two layers (4, 5) has nanoparticles which can emit a first spectral color and the second of the at least two layers (4, 5) has nanoparticles which can emit a second spectral color.
9. A body as set forth in claim 8, characterized in that the nanoparticles of the at least two layers (4, 5) are arranged in substantially mutually superposed relationship considered along the surface normal of the layers (4, 5).
10. A body as set forth in one of claims 1 through 9, characterized in that the marking (3) is made up of individual pixels (7), wherein each pixel (7) has at least one microhole (8).
11. A body as set forth in claim 10, characterized in that at least one of the pixels (7) has at least wo microholes (8), wherein arranged in a first of the at least two microholes (8) are nanoparticles which can emit a first spectral color and arranged in a second of the at least two microholes (8) are nanoparticles which can emit a second spectral color which is different from the first spectral color.
12. A body as set forth in claim 6 and claim 11, characterized in that the first of the at least two microholes (8) is arranged in a first of the at least two layers (4, 5) and the second of the at least two microholes (8) is arranged in a second of the at least two layers (4, 5).
13. A body as set forth in claim 12, characterized in that the two microholes (8) are arranged in substantially mutually superposed relationship considered along the surface normals of the layers (4, 5).
14. A body as set forth in one of claims 1 through 13, characterized in that the body (1) is at least substantially free of structures which absorb or scatter electromagnetic radiation in the visible spectral range.
15. A process for the production of a body as set forth in one of claims 1 through 14, characterized in that it includes the following steps:

    - producing the microholes (8) in the transparent material of the body, and

    - introducing the nanoparticles into the microholes (8).
16. A process as set forth in claim 15, characterized in that the microholes (8) are stamped into the transparent material.
17. A process as set forth in claim 15, characterized in that the microholes (8) are produced by laser bombardment of the transparent material.
18. A process as set forth in claim 15, characterized in that the microholes (8) are etched into the transparent material.
19. A process as set forth in one of claims 15 through 18, characterized in that the matrix (9) provided with nanoparticles is sprayed onto the surface (2) of the body (1).
20. A process as set forth in one of claims 15 through 19, characterized in that there are applied to regions of the transparent body (1) chemical compounds to which nanoparticles which are specifically surface-prepared for that purpose then adhere or which are avoided by surface particles which are specifically surface-prepared for that purpose.
21. A process as set forth in claim 19 or claim 20, characterized in that the matrix (9) is hardened after being applied to the surface (2) of the body (1) in the region of each microhole (8).
22. A process as set forth in claim 21, characterized in that excess matrix material which has remained on the surface (2) of the transparent body (1) is removed.
23. A process as set forth in claim 21 or claim 22, characterized in that a cover layer (14) having a plurality of pores (15, 16) is applied to the surface (2) of the body (1) after application of the matrix (9) to the surface (2) of the body (1) and prior to hardening of the matrix (9).
24. A process as set forth in one of claims 15 through 23, characterized in that, prior to the production of the microholes (8), a layer is applied to the surface (2) of the body (1), which layer reflect electromagnetic radiation in the spectral range of the hardening wavelength.
25. A process as set forth in one of claims 15 through 24, characterized in that prior to the production of the microholes (8), a layer is applied to the surface (2) of the body (1), which layer involves a greatly reduced bonding to the nanoparticle-doped matrix (9).

Images