DE2555559A1 - Optical image development using parallel gratings - has plane of spherically concave diffraction gratings with similar line spacings and specified relative positions - Google Patents

Abstract

The basic system of the optical image former uses two plane diffraction gratings (2,4) with rulings running in directions parallel to one another. The centre-lines of each grating (3,4) are also parallel. The angles (alpha 1, 2, beta 1,2) between the incident and diffracted rays for each grating follow simple trigonometrical relationship. Alternative systems use concave gratings, with spherical surfaces and similar line spacings. The distance between the central points of the gratings is close to the product of the radius of curvature of the grating and the cosine of the angle of incident radiation.

Description

Method of production

optical images The invention relates to a method for generating optical images of an object.

It is already known to use lenses for the optical formation of images and mirror surfaces to be used. When lenses are used, there is less refraction of light used in optical material. When mirror will be used uses the reflection of light from reflective surfaces.

The use of lenses is limited to the formation of images by radiation in those wavelength ranges in which the optical materials are transparent and have suitable refractive properties. This includes the Use of lenses to form images in certain wavelength ranges off, e.g., in the extreme ultraviolet wavelength range.

The use of reflective surfaces includes that the angles of incidence and reflection for the radiation with respect to each point are the same are where the radiation hits the reflective surface. So that the formation of Images can be used through a reflective surface, it is necessary that the image can be made so that it is on one side of the incident Radiation lies. This can be achieved by making the normal of the reflective Surface that passes through the center of the surface makes an angle with the incident one and therefore also forms with the reflected radiation. It is known that link with the most common reflective imaging: forming surfaces, such as those with a spherical or parabolic shape, errors of the image of the species Asthma and coma are produced with such non-axial incidence. if it is possible that the normal to the reflecting surface coincides with the direction of the fills the incident beam, however, one of these errors can be false Formation of the images can be achieved, but this image generation can only be used by inserting an optical member, e.g. of the deflection type, which member in turn is superimposed with the incident radiation.

Nowadays there are mainly two types of telescope mounts to obtain images of distant objects. One type of telescope has a achromatic lens, the image which is formed by this one through an eyepiece can be seen. This type of telescope is commonly called a refractor designated. The other type of telescope is spherical or parabolic Mirror which is arranged so that the incident radiation is parallel to the Normal surface of the mirror runs. After some kind of distraction with the help of one In With the member switched on, the image is viewed through an eyepiece. A telescope of this type is commonly referred to as a reflector.

Since lenses cannot be used in certain wavelength ranges, and because reflective surfaces cause errors in the image or a limitation of the incident Bringing radiation with it would be valuable if one were able to be refl ective to use imaging optical members or parts for which the EinSall- and angles of reflection are not the same, but can be chosen so that none Image errors with off-axis incidence arise. This object is achieved according to the invention solved by the use of diffraction with reflective gratings, creating both the wavelength-limiting properties of the lenses as well as the disadvantages of the reflective surfaces are eliminated.

The method of forming the present invention is therefore primary characterized in that at least two mutually counteracting (b3w. compensating) Diffraction grating as optical Limbs or elements for education of the illustrations can be used. Further features or refinements of the method according to the invention are characterized in the subclaims.

The invention is described in more detail below with reference to embodiments that are shown schematically in the drawing. In In connection with this, further advantageous features of the invention are explained.

The invention relates not only to what is characterized in the patent claims Process for the formation of optical images of an object, but also for the Execution of this method serving optical devices, which are shown schematically are shown in the drawing.

Fig. 1 generally shows two grids, which in mutually counteracting Diffraction are arranged; Fig. 2 shows a structure according to the invention for formation or generating an image of a distant object in a focal plane; Fig. 3 shows a structure according to the invention similar to that of FIG with a further grating r de selection of a narrowly limited wavelength range the incident radiation is provided; 1 shows a structure according to the invention for generating the image of a distant object in three different wavelength segments or sections of the incident radiation, which structure with the help of picture tubes an image in a radiation that is invisible to the human eye, which will be converted accordingly; Finally, FIG. 5 shows an embodiment for generating an achromatic image of an object in a focal plane.

In all the exemplary embodiments shown, the radiation path is like this chosen so that the central rays therein approximately correspond to the plane which by the normals to the central points of the grids and perpendicular to the alternately parallel lines of the grids in these central points.

In Fig. 1, the reference numeral 2 generally designates a reflection grating, which is provided in a known manner with parallel, equidistant lines, guhd at 4 is generally another, similarly provided with lines or scratches Reflection grating designated. A beam designated by 1 in FIG. 1 strikes the grid 2 in its central point 3 and is bent in the form of a bent or scatter ray 9, which the grating surface of the grating in its central point 5 hits. The beam diffracted after this diffraction at point 5 of the surface of the grating 4 is denoted by 6 in FIG. 1. The lines of the two grids 2 and 4 get one such an orientation that the lines at the central points 3 and 5 are parallel. Furthermore, in FIG. 1 the normal 7 to the surface of the grid 2 is at its central point 3 entered, as well as the e normal 8 on the surface of the grid 4 in its Central point 9 is shown. N Fig. 1 denotes the angle of incidence with α1, that between the incident ray 1 and the normal 7 locked in is; with β1 is the diffraction angle between that of the grating 2 at point 3 denotes diffracted ray and normal 7; with N2 is the angle of incidence between denotes the said ray and the normal 8 to the grating surface of the grating 4; where »2 is finally the angle between that by diffraction from the grating 4 Denoted at point 5 bent steel j and normal 8. The angles α1 and should be so determined that they have the positive mark. The angle ß1 should be positive if the beam 9 diffracted by point 5 is on the same side the normal 7 lies, like the ray 1 incident on point 3, and the angle ß1 should also have the positive identifier if the angle of incidence α1 to Grid area of the grid 2 becomes zero. The angle ß2 should be positive if the strand Ç bent from point 5 on the grating surface of grating 4 on the same The side of the normal 8 lies like the ray 9 incident at point 5 from point 3.

The grids 2 and 4 have, as said, reciprocal or mutual counteracting diffraction, if they are arranged so that the wavelength dispersion from grating 4 the wavelength dispersion from grating 2 seeks to counteract. With the code rule introduced above regarding the Angle α1, ß1, α2 and ß2, this means for the most general application of reflection gratings, where the expressions sinα1 - sinß1 and sinα2 + are both greater than zero that the grids 2 and 4 are such a geometric Designation or

have such a relationship to one another that an increase in the Diffraction angle from the grating surface of grating 2, which is denoted by p1, also an increase in the angle of incidence after the grating surface of the grating 4, the is denoted by α2, brings with it.

The following equations, known per se, apply to the diffraction in both grids: (I) # m1 = d1 (sinα1 + sinß1) (II) # m2 = d2 (sinα2 + sinß2), where the symbols α1, ß1, α2 and ß2 stand for the sizes in FIG. 1 described above. Furthermore, in these expressions ml means the so-called spectral order of the diffracted beam 9 from point 3 on the grating surface of grating 2; d1 is the distance between the lines or scratches of the grating 2, m2 stands for the spectral order of the diffracted beam 5 from point 5 on the smooth surface of the grating 4; d2 is the spacing of the lines or scratches in the grid 4; and is the wavelength of the beam diffracted from point 5 in the spectral order m1 and is at the same time the wavelength of the diffracted beam from point 5 in the spectral order m2 From the equations or expressions (I) and (II) the expression below is combined for the Wavelength dispersion found in both gratings 2 and 4, which is defined in a known manner by the derivative dβ2 / d #, where d can be interpreted as the infinitely small angular change in the diffraction angle 22 caused by a ray exceeding wavelength # by, provided that the Grids 2 and 4 in counter-diffraction are: The combined wavelength dispersion of both gratings 2 and 2 can be omitted if the gratings 2 and 4 can be set up or arranged in such a way that ### = 0. It can be seen from expression (III) that the wavelength dispersion is canceled if the following condition is met: (IV) cos β1 (sin α2 + sin β2) = cos α2 (sin α1 + sin β1).

The above expression can be obtained by applying equations (I) and (II) can be transformed, thereby obtaining the following condition, which is in their Content is equivalent to the condition expressed by the equation (IV) is: (V) ## cosß1 = ## cosα2.

These conditions (IV) or (V) can be met so that a higher or lower degree of cancellation of wavelength dispersion within a preselected wavelength range takes place.

The cancellation of the wavelength dispersion of both gratings means that rays that one of have different wavelength, from the grating surface of the grating 4 approximately at the same diffraction angle 02 with reference to the normal to the smoothing surface of the grid 4 at the point of accident of the beam in question go out onto the grating surface.

According to the invention it is possible to cancel the wavelength dispersion to use for picture formation. Such a structure for generating a Image of a distant object is illustrated in FIG. 2, which is a specific Figure 3 illustrates selection of the grids shown generally in FIG. In Fig. 2 means 10, a ray coming from an object at a great distance; this The beam is incident on a plane reflection grating 11 and hits its grating surface at the central point 12 of the surface. It is assumed that the object in question is so It is far from the fact that all rays emanating from this object should be parallel to the Ray 10 incident on the surface of the grid 11. In Fig. 2, the reference numerals denote 1: 5 and 14 two rays of different wavelength, which after diffraction start in the grid area of the grid 11 from the central point 12 of this area.

A beam 1: 5 hits a concave grating 15 of a known type, which e.g. has a spherical surface, in its central point 16 on the grating surface from which point after diffraction the beam in the direction of the Normal 19 goes out, which is erected on the grid surface of the grid 15 at point 16 is. The beam designated by 14 in FIG. 2 hits the grating surface of the grating 15 at a point 18. Both grids 11 and 15 have such an orientation that the incident ray 10, the ray 1: 5 and the normal on the grating surface of the Grid 15 at point 16 lie in the same plane which is perpendicular to the lines the grid 11 and 15 is at points 12 and 16, respectively.

In FIG. 2, the one bent at point 16 in the aforementioned normal direction The beam is designated 19, while the beam diffracted at the point 18 is designated 20 is.

One can see in Fig. 2 the angles oil1, P1 and which in Fig. 1 in general are shown. The angle P2, however, is in the structure shown in FIG Fig. 2 is zero. The ray marked 1: 5, which after diffraction in the spectral order m1 in the direction towards the grating 15 is bent below the Diffraction angle with respect to the normal 21 of the grating 11 on the grating surface in its central point 12 has the wavelength #. The one in the same Beam 14 diffracted at point 12 has the wavelength # + ##, and it is from the outer surface of the grating 11 at point 12 at the diffraction angle ß1 + # ß1 diffracted.

All rays coming from the distant object with the wavelength Ä, which is therefore on the grating surface of the grating 11 parallel to the beam 10 incident, Pwuca after diffraction in the grating surface of the grating 11 in the spectral order m1 depart from this grating surface parallel to the beam 13. These parallel radiators, which hit the grating surface of the grating 15, are focused at a focal point 22 on the normal of the grating from point 15 to point 17. As is known, this focal point is free from aberrations such as astigmatism and Coma. The distance of the focal point 22 from the point 5 on the grating surface of the Lattice 15 results from the expression R 1 + cosα2 and so it goes without saying that this is an error-free image of the distant object in the wavelength # forms. This image formation by diffraction in the direction of the normal from a concave grating is used, among other things, in the so-called Wadsworth spectrograph used. In the above expression, R means the radius of curvature of the concave grating surface in point 15.

The incident from the object is analogous to the preceding Radiation which is incident on the grating 11 and has the wavelength # + ##, according to Diffraction go out parallel to the beam 14.

It is now possible to show that when the angle # ß1 is proportionate is small and when the gratings 11 and 15 are arranged so that the diffraction is canceled that is, the condition (V) is satisfied, the formation of an image of the object c 'n of wavelength + ## also on the normal of the grating from point 16 to point 17 is obtained.

This mapping is formed at a distance along the named normal from point 16, which is determined by the following series expansion with reference to the angle Aß1: where α2 stands for the angle of incidence of the ray 13 against the grating 15, where R stands for the radius of curvature of the grating surface of the grating 15 at point 16, and D for the distance between the central point 12 of the grating surface of the grating 11 and the central point 15 the grid area of the grid 15, and finally the quantity 0 {(# ß1) 2} stands for the remainder of the expression, which contains expressions of the second and higher powers of a »1.

It is apparent from this expression that the distance D is chosen becomes that the following condition is met: (VI) D = R cos where the mapping formation in the wavelength X + AN approximately coincides with that in the wavelength . The combined conditions (V) and (VI) constitute the conditions for generation an almost achromatic image of the object.

The condition (VI) means that the grids 11 are so arranged should that its central point 12 on the grid surface on the so-called Rowland circle of the concave grating 15 is located.

So it is understood that with the arrangement illustrated in FIG of the two grids achromatic images are obtained, which are to a high degree free from aberrations, like those images which with the help of reflective surfaces with incidence of rays at right angles of the normal to this surface can be obtained, but with the remarkable advantage that it is possible without any distractors to achieve that the images according to the invention it lies outside the path of the incident beam. Arrangements or devices according to the invention can be used for the widest possible range achieve the formation of images in radiations in which no lenses are used can be, such as in the ultraviolet wavelength range.

A telescope arrangement according to the invention such as that shown in Fig. 2, for example 1 and which is arranged so that the conditions (I) and (VI) are filled, represents a new type of telescopic arrangement. Analogous to the previously known types of telescopic assemblies or devices, which to be referred to as refractors and reflectors or mirror telescopes, the Telescope arrangement described above or

device according to the invention hereinafter referred to as a diffractor will.

The present invention also opens up new possibilities for Image formation in limited wavelength intervals of the radiation, thanks to the Freedom in the choice of the grid line spacing and the spectral order which the Condition (V) allowed. This is due to the structure of the arrangement shown in FIG or device shown. That is, when the incident radiation has a wavelength with the deviation AX from the wavelength λ, which is so great that the im Grating 11 at the diffraction angle ß1 + # ß1 diffracted radiation the grating surface of the grating 15 does not hit, this radiation apparently does not contribute to the formation of the image will contribute.

By choosing suitable line spacings and spectral orders for de grids 11 and 15> for which conditions (V) and (VI) are met achromatic images of the object in limited wavelength ranges of various types Widths or expansions can be achieved. This is illustrated in the following by means of two main exemplary embodiments explained. In these examples the grids 11 and 15 have the same grid line spacing, and they are arranged in such mutual relation that the diffraction of both gratings in the same spectral order occurs, i.e. d1 = d2, m1 = m2. From this initial choice it follows from the condition (V) that also ß1 = α2, i.e. that the grids should be arranged in such a way that their smooth surfaces In the central points 12 and 1 are parallel.

With this initial choice one finds from equations (I) and (II), that the entire structure of the device shown in Fig. 2 must be oriented so that the radiation from the object onto the grating 11 is parallel to the normal 10 this grid comes to mind. This choice of structure or arrangement is the very easy to understand diffractor arrangement. When so-called cracked grids are used become, i.e.

Grids in which each line has an approximately step-like profile, the so-called blaze angle must be chosen so that the highest radiation output or energy yield is achieved.

In the case dealt with here, this means that the beam angle (blaze angle) both for the plane grid 11 and for the concave grid 15 target.

In those cases in which a wide range of wavelengths is desired within its an achromatic image formation should be achieved, a thin or sparse line spacing is chosen so that that the lattice constants d1 and d2 are large or wide compared to the longest Wavelengths of the radiation with which the image is to be formed. at Such a choice of the line spacing will reduce the incident radiation from the grating 11 and thus also diffracted by the grating 15 in close spectral orders. i.e. m1 and m2 are considerably larger than 1. The wavelengths of the grating 11 after diffraction in the different spectral orders at the diffraction angle ß1 outgoing radiation is determined by the equation (I) given above, which results in: - ## sinß1.

From the above equation it can be seen that these wavelengths in closely adjacent spectral orders are close to each other if the spectral order m1 is high. It is therefore only necessary to use a small wavelength element in neither to allow spectral order m1 to apply to the concave grating 15, whereby the entire, desired wavelength range in which the imaging is carried out earth should, from the small wavelength segments or sections a plurality of spectral orders is composed. This also means that, the higher the spectral orders with which one works, i.e. the further the distance the lines of the grid, the smaller the total variation or deviation t4l of the diffraction angle will be which the concave grating 15 for the image image formation can capture or capture. In accordance with the above this means that the achromatic correction in the image formation is still is further improved.

In those cases where it is laundered, just one tight limited wavelength range of radiation for achromatic imaging of the object, one can choose to work in low spectral orders, for example m1 = m2 = 1 or 2, which means a high line density of the grids 11 and 15 makes it necessary.

For example, if one works in the spectral order 1, it means that the line spacing of the two grids 11 and 15 in accordance with the expression d = d2 = / sin should be chosen, where # is the central wavelength is in the wavelength segment or portion of the radiation in which the image is formed, and where as before ß1 = α1 the diffraction angle from the grating 11 or the angle of incidence with respect to the grating 15, namely with the wavelength #. Since a high line density has been chosen, the wavelength dispersion becomes be high from the grid 11. As a result, only the radiation that is one of # has slightly different wavelengths, hit the concave grating 15 and so on be included in the image formation. The intensity distribution around de central wavelength of the spectral wavelengths which are involved in the formation of the image will be essentially bell-shaped. One finds in such a structure with e.g. # = 1500 R, m1 = m2 = 1, d1 = d2 = 0.417 µm (line density 2400 1 / mm), R = 1000 mm, ß1 = α2 = 21.1 °, D = R cosα2 = 933 mm and where both grids have a square grid area measuring 40 mm by 40 mm, since the so-called half width of the bell-shaped distribution will be about 1600 Å. With this structure, there is also an image forming process in a segment centered around 750 R. in the spectral orders m1 = m2 = 2, an image formation in a segment centered around 500 Å in the Spectral orders m1 = m2 = 3, etc. take place. But this disorder or impairment by high spectral orders can usually be limited, e.g. by suitable Choice of detector. The determined half-life can still be achieved through application a higher line density has been reduced.

In the example discussed above, the invention is applied to achromatic Imaging applied in a wide range of wavelengths without being excessive Angular diffractions from the grating 11 occur. in the latter, discussed above For example, the invention is selected for achromatic image formation Section of the wavelength of the incident radiation Applied.

The diffraction grating according to the present invention can also t7, 'v other optical members or parts are combined. An example for such a combination is illustrated in FIG.

The same plane lattice 11 and the same concave lattice can be seen here 15 in the same diffractor setup shown in (Fig. 2. Instead of the radiation is enabled by the distant object to apply to the plane grid 11, As is the case in Fig. 2, the arrangement is made in Fig. 3 so that the Radiation from the object hits a plane grating 30 from which the diffracted radiation the plan grid 11 can occur. The lines of the plane grid 30 are parallel to the Lines of the plan grid 11 arranged. The grid 30 is arranged so that his wavelength dispersion resulting from the diffraction with the plane grating or flat grid 11 cooperates. By choosing a high density of lines for everyone Grating in the structure according to FIG. 3 is possible due to the cooperating wavelength dispersion the gratings: 50 and 11 a narrow wavelength segment and wavelength segment for to choose the achromatic image formation. In this way it is even possible the earlier wavelength selection properties with the help of the plan grating that has now been introduced of the structure shown in FIG. 2 to be increased further.

In order to further demonstrate the possible uses of the invention, In Fig. 4, a structure or an arrangement is shown which comprises a plane grid 40 (or a concave grating) on which the radiation from the distant Object occurs. In Fig. 4, concave grids 41, 42 and 4 are also provided, which are arranged with respect to the plane grid 40 that the conditions (V) and (VI) of the achromatic image formation according to that shown in FIG Diffractor principle for each concave grating in its combination with the PlangItter 40 are not applicable. as a result, points 44, 45 and 46 become achromatic Get images of the removed object that are free from errors.

By suitable choice of the line densities of the concave grating and the flat one or plane grid and by arranging the concave grids 41, 42 and 43 in such a way, that they have different wavelength segments or sections of the from the grating 30 The images in the points can capture or capture diffracted radiation 44, 45 and 46 are generated so that they have achromatic images of the object in three wavelength segments or sections of the incident radiation. It can thus be understood that the invention applies to simultaneous achromatic image formation of an object in a plurality of wavelength segments or -sections can be used.

If you allow Figures 44, 45 and 45 to point to the only schematically indicated photocathodes of picture tubes 47, 48 and 49 focused the three images can be used to generate titanium visual images using the same technology that is used in color television cameras is used.

With a structure or a device for images enjoy Fig. 4 with restriction to three wavelength segments or sections e.g.

in the ultraviolet wavelength range invisible to the human eye Is it possible to produce colored images in radiation that is visible to the eye is visible, namely by means of the images produced by the picture tubes 47, 48 and 49 can be perceived in ultraviolet radiation. Such an arrangement or device uses the color vision of the eye and the extraordinary Image analysis ability of the human brain to analyze images in the for radiation invisible to the human eye.

in such a method according to the invention is called color image transformation designated.

The embodiment of the invention according to FIG. 5 shows the production an achromatic image of an object in a focal plane. The object is denoted by 50 in FIG. 5. The incident radiation from this object is incident a concave grating denoted by reference numeral 51.

This concave grating divides the incident radiation by diffraction in different wavelengths and forms an image of the object in these wavelengths in an imaginary focal plane, which is designated by 52 in FIG. 5. Hipter the In the focal plane 52, the radiation hits another concave grating 53, its wavelength dispersion so x is chosen that it cancels the wavelength dispersion of the grating 51, whereby Obtain an accurate achromatic mild of the object 50 in a second focal plane will. An arrangement for image formation as shown schematically in FIG. 5 can be particularly valuable in connection with imaging processes, where the elimination of the disturbance of one or more wavelengths is desired Such an elimination can e.g.

can be achieved with the aid of a screen which is located in the focal plane 52 is arranged so that part of the spectrum produced by the grating 51 is shielded will. As a result, no radiation of such wavelengths that are in the focal plane 52 hitting the screen, contribute to the formation of the achromatic image shown in the Focal plane 54 is generated. The elimination of such wavelengths has, for example, a special one Significance for the recording of so-called Raman spectra.

The invention is not limited to the choice of parameters or of structures, arrangements or devices according to those described above and the exemplary embodiments shown in the drawing. So it is clear that the Invention can be carried out in the same way or similar if the radiation runs in such a way that the central rays in the arrangement form angles with the planes, which run through the normals established at the central points of the grids and which are perpendicular to the grid lines in the central points mentioned. Further The invention can be applied in numerous different ways within the scope of the following patent claims Manner can be varied, e.g.

through appropriate selection of the parameters in the exemplary embodiments shown, in order to achieve optimal results in every special case. otherwise limited The invention does not apply to the claims described above or in the claims labeled procedures, but it also includes all of the execution of these Processes, for example devices shown in the drawing, Arrangements and devices or the like.

Claims

Claims (14)

P a t e n t a n s p r ü c h e: 1. Process for the production of optical Images of an object, characterized in that at least two each other counteracting diffraction or diffraction grating (2, 4) as optical elements for the mapping education can be used. 2. The method according to claim 1, characterized in that the lines the at least two mutually opposing diffraction gratings (2, 4) in the central points (3, 5) of the grid surfaces approximately parallel in the positions or imaginary positions which the grids have when all the optical elements which may be placed in the radiation path between the grids has been removed are. j. Method according to one of Claims 1 and 2, characterized in that that the shape, the density of lines and the mutual distance of the grids are so chosen that the wavelength dispersion from the first grating (2) is at least approximately is canceled or balanced by the second grid (4). 4. The method according to one or more of claims 1 to 5, characterized characterized in that limited wavelength ranges for the imaging process of a diffracted radiation can be used in the grating. 5. The method according to one or more of claims 1 to 4, characterized marked that the grid consists of a flat grid or plane grid (11) and a Concave grating (15) exist, the figure being on the normal to the de grid surface of the concave grating, which runs through the central point (15) of this grating. 6. Movers according to claim 5, characterized in that a concave grating (15) is used with a spherical upper pleading. 7. The method according to claim 5, characterized in that a concave grating (15) is used, the surface of which is a paraboloid of revolution. 8. The method according to any one of claims 5 to 7, characterized in that that grids (11, 15) are used with the same line density. 9. The method according to claim 8, characterized in that the plane or plane grid (11) is arranged such that the radiation (IO) in approximately at right angles to the grid surface of the flat grid. 10. The method according to claim 9, characterized in that the plane or the plane grille (11) and the concave grille (15) in such a mutual relationship are arranged that their grid surfaces or their grid lines in their central points (12, 15) are at least approximately parallel. 11. The method according to one or more of Claims 5 to 10, thereby marked that the distance (D) between the central points (12, 15) of the grid surfaces is chosen such that it is approximately determined by the product of the radius of curvature (R) the grating surface of the concave grating (15) in its central point (15) and the Cosine of the angle (α2) that the radiation incident on the concave grating (15) with the normal to the grating surface of the concave grating in the named central point forms. 1. The method according to one or more of claims 1 to 11, characterized characterized in that an image of one and the same object in at least two Formed limited wavelength ranges of the incident radiation from the object will. 13. The method according to one or more of claims 1 to 14, characterized characterized in that the grids consist of two concave grids (31, 33). 14. Devices, devices, instruments or the like. or other for the Formation of optical images of objects for carrying out the method or methods according to one or more of claims 1 to 1), characterized by the in these Claims or in the description of the invention specified optical means or Elements and their training, arrangement and combination.