DE3141789A1 - Sunbeam concentrator and method for producing it - Google Patents

Description

3H1789

1 . Viktor Voskanovich AFlAN ₉ Erevan

2. Albert Vartanovich VARTANIAN, Erevan

3. Ruben Gegamovich MARTIROSIAN, Erevan

4. Stanislav Vasilievich RYABIKOV, Moscow

5. Dmitry Semenovich STREBKOV, Moscow

6. Eduard Vladimirovich TVERYANOVICH, Moscow

USSR

Sunbeam concentrator and process for its manufacture ''

The invention relates to optics and, more particularly, to solar concentrators and their production ..

The sunbeam concentrator according to the invention can be used in the Heliotechnology used to concentrate solar radiation falling on the work surface of a photo converter will.

It is a sunbeam concentrator in the form of a prism with a triangular base made of a material with high refractive index known (D. R. Mills, J.E. Giurtronich, "Ideal prism solar concentrators", "Solar Energy"., 1978, 21, N. 5, pp. 423-430), in which the radiation concentration comes about through multiple total reflections.

The prism has surfaces for entry, reflection and exit of rays. The lower reflection surface of the Prism has a mirror coating, while the dihedral angle between the upper entrance surface of the prism and the Reflection surface with consideration for a total reflection of a the light beam that has entered the prism is selected and approx.

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20 °. The multiple reflected rays leave the exit surface opposite this dihedral angle of the prism.

The multiplicity of concentration, which can be defined as the area ratio of the entrance area to the exit area, proves turns out to be low and amounts to approx. 3. The concentrator has large dimensions and dimensions. In addition, the entire spectrum of the sun's rays is concentrated, resulting in a uneconomical conversion of solar energy by a selective recipient, e.g. B. a photo converter that leads reaches a maximum sensitivity in a certain spectral range.

DE-PS 2 629 641 discloses a selective sun ray concentrator in the form of a transparent prism - a plane-parallel plate - with dispersed in its volume Luminescence centers known to have an incident on them Radiate radiation in a longer-wave spectral range. To increase the degree of concentration is on the lower plate surface and a reflective layer on all side surfaces with the exception of the exit surface applied.

In this concentrator the luminescence radiation spreads within the plate in all directions, with that impinging on the plate surfaces from the inside at a smaller solid angle than the critical angle of total reflection Luminescent radiation leaves the plate and is lost. For a glass plate with a refractive index of 1.5 these losses approx. 25%. In principle, such losses cannot be eliminated. Significant losses also occur due to self-absorption and reflection at the reflection

areas on. This luminescence concentrator also has shortcomings Difficulties in the synthesis of a phosphor suitable for spectral characteristics as well its instability and short lifespan.

Finally, US Pat. No. 4,054,356 discloses a sunbeam concentrator known, which is designed in the form of a lens or a hologram of a light point source. One of those Concentrator is simple to manufacture, it is made by recording an interference image of a plane-parallel reference and a diverging object bundle of laser radiation in a layer of a light-sensitive Material generated. The focal length of this lens turns out to be large and is due to the location the source of divergent radiation. For the arrangement of a receiver for concentrated radiation at the focal point of the lens it requires the receiver with the lens connecting auxiliary device. In addition, the energy distribution falls across the surface of the receiver very unevenly.

Concentrators are used to concentrate solar radiation of interest, which do not produce an image of a radiation source and a more uniform energy distribution immediately ensure over their exit area.

The invention is based on the object of creating such a sunbeam concentrator, its construction a reduction in energy losses in the concentration of solar radiation, an increase in the degree of concentration, an expansion of the possibilities for a concentration of different spectral ranges of the

Solar radiation, the possibility of simultaneous to ensure separate concentration of the different spectral ranges on different beam exit surfaces able.

The invention is also based on the object To simplify manufacturing technology for solar beam concentrators.

The problem is solved in that in one Sunbeam concentrator, which is designed in the form of a prism, the surfaces for entry, reflection and exit of rays, according to the invention, a material layer on the entrance surface and / or on the reflection surface is arranged with a spatial hologram generated therein, which is arranged on the entrance surface of the transmission type and on the Reflective surface of the reflection type and each constructed in such a way that the radiation enters the prism at a total reflection angle is introduced.

For specifying the spectral characteristics of the sunbeam concentrator over a wide range it is useful to set the angle between the entry surface and the reflection surface to choose at least half an angular deviation from the Bragg angle at which the diffraction effectiveness of the hologram is minimal.

To increase the degree of concentration of solar radiation is it is desirable to choose the parameters of the hologram in such a way that the radiation in the prism propagates parallel to the surface, which is opposite to that on which the hologram is located.

If the prism has the shape of a parallelepiped, it is expedient to have the spatial hologram with a non-uniform To carry out a structure to prevent diffraction of a beam propagating within the prism, which is reflected from the hologram / air interface.

In order to expand the spectral range of the solar radiation to be concentrated, the spatial hologram can be multilayered are carried out, each layer information about a light source with one of the wavelengths of the contains light sources of different wavelengths used to generate the holograms in the other layers.

Here it is desirable for more effective use of solar radiation, the number of layers of the spatial Holograms equal the number of exit surfaces and the structure of the hologram of each layer taking into account the direction of radiation on the corresponding exit surface to choose.

The object set is also achieved in that, in a manufacturing method for a sunbeam concentrator with recording of an interference image from a reference and an object bundle of laser radiation in a photosensitive layer according to the invention, this photosensitive layer on the entrance surface and / or is applied to the reflective surface of a prism and the recording of the interference image takes place by the reference beam in the direction of the one to be concentrated Radiation and the object bundle at the total reflection angle of the materials of the photosensitive layer and of the prism is steered.

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To ensure greater freedom of choice for the too concentrating spectral range when using a prism with a trapezoidal base can be used as Object bundle uses a light radiation with a flat wavefront and onto one of non-parallel prism surfaces be directed, which are chosen as the entrance and reflection surface.

In this case, the entry angle for the reference bundle in the prism is expediently corresponding to formula

Θ ¹ sr β + 2 fm,

to choose where

Θ ^{1 is} the angle of incidence of the object bundle on the entry surface of the prism,

ß the critical angle for total reflection at the prism / air interface,

ψ ' the angle between the entrance surface and the reflective surface of the prism and

m is the maximum number of multiple reflections of a beam a radiation to be concentrated within the prism.

When manufacturing a sunbeam concentrator on the basis of a prism with a rectangle as a base if light radiation with a diverging wavefront is expediently used as the object bundle, its source is arranged in such a way that a section on the hologram / air interface between the entry point of a Ray and the point of its first reflection from the interface Hologram / air at an angle of no less

as the angular deviation from the Bragg angle at the point of The first reflection mentioned above is visible, at which the diffraction efficiency of the spatial hologram is minimal.

When manufacturing a sunbeam concentrator with a multilayer hologram, it is advisable to use the first photosensitive layer to apply at least one more photosensitive layer and on each of the layers record an interference image from a light source at one of the wavelengths used for recording light sources of different wavelengths are used for the interference patterns on the remaining layers is made, and the values of the wavelengths for all light sources taking into account one Lack of the effect of a cross modulation can be chosen.

Here you can determine the number of layers of the spatial hologram according to the number of exit surfaces of the Select concentrator and record an interference pattern in each slice by moving the object beam towards is directed to an exit surface corresponding to the respective layer.

The sunbeam concentrator embodied according to the invention leads to the concentration of an optional area of the Solar spectrum, to a reduction of the energy losses in the concentration and to a high degree of concentration. The concentrator is simple in construction and contains the smallest possible number of components. The manufacturing process for the concentrator stands out more labor intensive due to simplicity and lack

Operations for mechanical processing of the surfaces of the optical elements. By generating a corresponding structure of the diffraction grating of the spatial hologram on the way of application of light sources with different wavelengths becomes a more effective use of the solar radiation spectrum with the possibility of a separate concentration of different spectral ranges.

The invention is intended below on the basis of specific embodiments illustrated in the drawing are explained in more detail. Show:

Fig. 1 shows a solar beam concentrator and a device for producing a spatial Transmission type holograms on the entrance surface of a prism with a triangular base;

2 shows a sunbeam concentrator with a prism with a trapezoidal base and a spatial hologram of the transmission type on the entrance surface;

3 shows a sunbeam concentrator with a prism with a trapezoidal base and a reflection type spatial hologram on the reflection surface;

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• ν «· W

4 shows a solar beam concentrator in the form of a parallelepiped and the direction of radiation of an object bundle with it Manufacture;

Fig. 5 shows a sunbeam concentrator in the form of a Paralleepipeds with a spatial hologram of the aperture type on the entrance surface and a reflection type spatial hologram on the reflection surface;

6 shows a sunbeam concentrator in the form of a parallelepiped with a two-layer Passage type hologram on the entrance face and with two exit faces.

The sunbeam concentrator shown in Fig. 1 consists of a prism 1 with a triangular base, the one Entry surface 2, a reflection surface 3 and an exit surface 4 for radiation as well as a layer 5 applied to the entrance surface 2 and composed of a light-sensitive Material having a transmission-type spatial hologram formed therein. The structure of the diffraction grating is such that the introduction of the radiation into the prism is at a total reflection angle θ and at an illumination of the concentrator by means of a reference beam used in the recording of the hologram 6 identical light bundles is guaranteed, whereby

1 .

the light rays inside the prism parallel to the reflection, Spread out onsflache 3.

In another embodiment of the same concentrator the spatial hologram can be located on the reflective surface 3 (not indicated in the drawings). In this Fall ensures the structure of its diffraction grating for the hologram, reflective properties and the propagation of the in the prism 1 entered radiation parallel ^ ur rays intrittsflache 2.

The solar concentrator shown in FIG. 2 consists from a prism 1 'with a trapezoidal base

area 2
and with an entrance 'and a reflection surface 3, and, with two exit surfaces 4 and 4' and made of a material layer 5 with a spatial transmission hologram produced in this. The surfaces 2 and 3 are non-parallel in the prism 1 '. The parameters of the diffraction grating of said hologram are such that when the concentrator is illuminated by the light bundle identical to the reference bundle 6

1 / »■■■■■"

■ this is introduced into the prism at the total reflection angle σ to the entrance surface 2 and continues in the direction of the exit surface 4. The direction of an object bundle 7 to the prism 1 'in the formation of the diffraction grating of the spatial hologram is indicated by dotted lines.

In contrast to that shown in FIG. 2, the concentrator shown in FIG. 3 has a material layer 5 'with a spatial reflection holoyramm on a reflection surface 3 on. The structure of the diffraction grating of the hologram

1'
is such that what has entered the prism with the reference

1 'bundle of identical light bundles within the prism under one

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Total reflection angle & * larger than the angle Θ is reflected and is directed in the direction of the smaller exit surface 4 'of the prism 1 ″.

a

Another embodiment for sunbeam concentrator 4 consists of a prism 1 "in the form of a rectangular parallelepiped with an entry surface 2, a

and
ner reflective surface 3, two exit surfaces 4 and 4 * and made of a material layer 5 with a spatial transmission hologram. In contrast to the concentrators shown in FIGS. 1 to 3, the above-mentioned hologram has a non-uniform structure to prevent diffraction of a beam which continues within the prism 1 ″ and is reflected by the hologram / air-air interface.

5 shows an embodiment of a concentrator whose difference from that shown in FIG. 4 is that a material layer 5 'with a three-dimensional reflection hologram rests on the reflection surface 3 of the prism 1 ″. The parameters of the diffraction gratings of the holograms are selected in this way that (bchicht 5) on the hologram .Durchlaßtyp a spectral range with wavelengths near / I - | and on the hologram Keflexionstyp (layer 5) · spectral range with wavelengths near λ diffragiert the radiation of these two areas is on the exit _surface?. 4 focused.

Another embodiment for a sunbeam concentrator is in 'opposite

Fig. 6 shown. Its difference / according to the concentrator Fig. 4 is that the spatial transmission hologram in of layer 5 "is made in multiple layers, the number of Scaling of the hologram is equal to the number of exit surfaces

3-4

for the concentrated radiation is. To illustrate this, FIG. 6 shows a two-layer hologram of the transmission type, one layer of which directs the concentrated radiation with wavelengths near λ ^ onto the exit surface 4 and the other layer directs the radiation with wavelengths near λ ^ onto the second exit surface 4 ' .

The manufacturing process for the shown in Fig.1 Sunbeam concentrator consists in the following. On the entry sflache 2 of the prism 1 becomes a layer 5 of a photosensitive Materials, for example a loto emulsion. upset. A layer 8 of an immersion liquid is applied to the layer 5 of the photosensitive material an index of refraction close to the index of refraction · of the photosensitive Material applied and an auxiliary prism 9-.auf-, posed. The auxiliary principle is used to guide the reference bundle 6 in the direction of the radiation to be concentrated and the object bundle 7 parallel to the reflection surface J. In the light

bundle 6 sensitive layer 5 is an interference image from the reference

and the object bundle 7 · the laser radiation recorded.

The Dar chi alihol ο gram proves to be homogeneous because

bundle 6

the reference and the object bundle 7 each have a plane wave front. To obtain a reflection hologram in a concentrator based on a triangular prism 1, the light-sensitive layer is applied to the reflection surface 3, while the object bundle 7 is directed parallel to the entry surface 2 of the prism 1. In the sunbeam concentrator according to Pig. 1, the angle ψ between the entrance surface 2 and the reflection surface 2 clearly defines one. Angle between c-on the reference bundle 6 and the object bundle 7, the

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in turn, spectral characteristics of a spatial hologram generated in the light-sensitive layer 5 are determined.

The embodiment according to FIG. 2 with a trapezoidal prism 1 'offers a large selection option for specifying the spectral characteristics of a concentrator. In the manufacture of such a concentrator, the object bundle 7, in contrast to the manufacturing method for the concentrator according to FIG. 1, is directed onto the prism 1 'at an optional total reflection angle for the material of the prism 1', starting with the critical total reflection angle β. In this case, a light radiation with a flat wave front is used as the object bundle 7. The angle * f 'between the entrance surface 2 and the reflection surface 3 can be selected within the limits of 45 to 0/2 , where & means the angular deviation from the Bragg angle at which the diffraction efficiency of the spatial hologram is minimal. In order to achieve a high degree of concentration for the light radiation, it is expedient to take the angle Ψ ^χ equal to υ / 2 . The object bundle 7 is directed onto the prism 1 ′ in the direction of the exit surface 4.

The manufacturing method for the concentrator shown in Fig. 3 consists in that a photosensitive layer 5 'is applied to the reflective surface 3 and an interference image is recorded by directing the reference beam 6 and the object beam 7 onto the photosensitive layer 5' from their opposite sides . Here, the object bundle 7 is introduced into the prism 1 'at an angle Θ ¹ to the entrance surface 2, the limit total reflection angle ß by at least a product of the number of reflections of a beam on the

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Reflection surface 3 and twice the angle ¹ P '
between the entrance surface 2 and the reflection surface 3
of the prism 1 'exceeds the same angle. This condition
is described by the following relationship:

Θ ^ Β + 2 sc,

where Θ 'is the angle of incidence of the object bundle on the
Entry surface 2 of the prism 1 ',

ß the limit total reflection angle at the prism / air interface,

^ f ^{1 is} the angle between the entrance surface 2 and
Reflection surface 3 of the prism 1 'and

m is the maximum number of multiple reflections of a
Beam of radiation to be concentrated
within the prism 1 '

designated.

In addition, the described manufacturing process for the concentrator of FIG. 3 differs from the manufacturing process for the concentrator according to FIG. 2 in that the
Object bundle 7 is introduced into prism 1 'in the direction of exit surface 4 ¹ .

In the manufacturing process for the concentrator according to
4, a prism 1 ^f 'in the form of a rectangular parallelepiped is chosen, on the entrance surface 2 of which a light-sensitive layer 5 is applied, and an object bundle 7 with a diverging wavefront is used when recording an interference image. Here, the position of the source P for the object 7 is selected flush with respect to the entry surface 2 in the manner _; that a section at the interface
Hologram / air between the point of entry of the beam and the

Point of its first reflection at the interface hologram /

from

Air at an angle not less than a one-half angular deviation from the Bragg angle at the point of the first mentioned above Reflection can be seen at which the diffraction effectiveness of the spatial hologram is minimal. The - ^ fulfillment of this condition in the lalle of the arrangement of the spatial transmission hologram on the entrance surface 2 is observed in compliance with the the following ratio is guaranteed:

2 (d + U ₁ ) tgod ih [tg (pi _Q + ^ ₀ ) - tg oC _o ],

where d is a distance between the entrance and the reflection surface ,

d-j- the thickness of the spatial hologram, h is the distance from the source for the object bundle

up to the hologram / air interface , oC a total reflection angle at the interface

Pr isma-I / uf t,
cL one associated with oC by the law of refraction

Incidence of a beam of Objektbündelsund angle $ an angular deviation from the ° ^ _0/2 identical Bragg

Angle at which the diffraction effectiveness of the spatial Hologram is minimal, designated.

In deriving this ratio, the refractive indices of the material layer with the spatial hologram and the

at
of the prism because they are usually

only
the / differ slightly. The refractive index of the medium in which the source P of the object bundle 7 is located is assumed to be different from the refractive index of the prism 1 ″.

3 Ί 41783 V ": -" :: l · Γ: 1

In the special case of the same number of bays, the angle <? C is equal to the

Angle to put egg. In addition, the thickness d _{T of} the ο 1

spatial hologram in Hegel is much smaller than that. Distance d between the entry surface 2 and the reflection surface ⁷ j and can be neglected. The steering of the object bundle 7 at a required angle can be ensured, for example, with the aid of a corresponding auxiliary prism and a layer of an immersion liquid on the internal surface 2.

• The manufacturing process for those in Pig. The embodiment of the concentrator shown in FIG. 5 consists in that a light-sensitive layer 5 is first applied to a surface, for example on the entrance surface 2, and a spatial transmission hologram is generated in this by a light source with a wavelength λ-j-. A corresponding photo-chemical treatment is then carried out on this section. Then a light-sensitive layer 5 * is applied to the reflection surface 3, in which a spatial reflection hologram is generated by a light source with a different wavelength λ. ^ And a corresponding photochemical treatment of this layer is carried out. In the production of such a concentrate or s, the wavelengths A and ^ p of the light sources are chosen with a view to the absence of cross modulation. As an example, a concentrator is shown in FIG. 5, during the manufacture of which the two object bundles in

the prism 1 ″ introduced in the direction of the exit surface 4 will.

The concentrator shown in FIG. 6 is manufactured in a similar manner, in which the number of layers of the spatial

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Holograms according to the number of exit surfaces is selected. The layer of the spatial hologram is on the entry surface. before 2 applied. First, the first light-sensitive layer is applied and a three-dimensional hologram is generated therein by directing the object bundle in the direction of the first exit surface 4 and by using a light source with a wavelength Λ _χ . A second light-sensitive layer is then applied and a three-dimensional hologram is applied therein by directing the object bundle in the direction of the second exit surface 4 'and by using it. a light source with a different wavelength ^ ₂ generated. Then further layers can be applied and the operations described can be repeated. Here, the wavelengths A ^ and ^ p of the light sources are chosen in the same way, taking into account a minimization of the effect of the cross modulation, so that the light of one wavelength only acts on "its" diffraction grating d if fr and formed with others by the light sources of the other wavelengths Layers of the hologram do not interact.

Constructively, all concentrators can have a prism made of an optically transparent solid material. About that In addition, the prism can be used, for example, to improve temperature conditions for the work of the recipient of the concentrated Radiation can be carried out in the form of a plague body shell filled with a transparent liquid.

in operation of the sunbeam concentrator according to the invention sets the spatial hologram

spatial diffraction grating, the periodically arranged

3U1_7§ ₃ 9_

Contains scatter surfaces. One falls with one of the two at the Formation of the hologram involved waves identical light wave at such a grating under one. Bragg-lVinkel a, it diffuses it and recreates a wave identical to the second wave. Therefore this puts through the plane-parallel reference bundle 6 and through the object bundle 7 introduced into the prism at the total reflection angle # spatial hologram formed when illuminated by the

Reference bundle 6 restores the object bundle 7. Thereby, a light beam from the air in ea ^s optically denser medium

1
of the prism / introduced at the total reflection angle.

The spatial hologram has an angular selectivity, ie a dependence of the diffraction efficiency on the value of the angular deviation of the illumination beam from the Bragg angle, the permissible angular deviation being smaller, the greater an angle equal to "twice the Bragg angle" when forming the hologram between the reference bundle 6 and the object bundle η

Hologram selective for the wavelength of the illuminating radiation, which is why it is illuminated by sunlight a certain spectral range depending on the conditions for the generation of the hologram can concentrate. '

The concentrator according to .Fig. 1 points to the entry area 2 a spatial Dur chi alihol ο graium on, which the in the Prism 1 entering radiation parallel to the reflection surface 3 heads. Opposite de :: in Fig. 2 and 3 shown Kon- "" centrators he concentrates at equal angles "between the

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Entry surface 2 and the reflection surface 3 a relatively narrower spectral range because of a larger angle between the reference beam 6 and the object beam 7 of radiation. There are no multiple reflections of the

1 concentrated light radiation inside the prism.

The concentrator of Fig. 2 operates as follows. the

a light radiation identical to the reference bundle 6 diffuses at spatial transmission holograms by impinging on a material layer 5 with this, and enters the prism 1 'at the total reflection angle θ . After the reflection from the reflection surface J inclined to the entrance surface 2 at a 7 / angle of ψ ' , the beam strikes the interface hologram / air at an angle of θ + zf and experiences total reflection. The angle ψ ' is chosen not to be less than half an angular deviation from the Bragg angle, at which the diffraction efficiency of the hologram mentioned is equal to zero.

Since the beam reflected by the hologram / air interface does not hit the scattering surfaces of the spatial hologram at the Bragg angle1, but with a deviation of the angle 2 ψ ¹ , at which the diffraction efficiency of this hologram is equal to zero, it differs from it not. Its direction does not change, and after a series of multiple reflections it exits through the exit surface 4.

In the JFig. 3 corresponding embodiment of the

centrator with a trapezoid as a base

Prism is the radiation on the smaller exit surface 4 '

concentrated. As an example, an embodiment is shown with a spatial - ^ eflexionsholograjum lying on the inflexion surface 3 in the Schioht 5 '. When generating the diffraction grating of the above-mentioned hologram, the object bundle 7 is introduced into the prism 1 'through the flexion surface 3 at the angle 0' . In contrast to the concentrator shown in FIG. 2, this angle is reduced by a fourth of 2 ψ after each reflection from the surface 3. So that the beam ^{does not leave the prism 1} 'through the entry surface 2 or the keflexionsfläche 3, the angle ¹ is impared

to the limit total reflection angle ß by an angle larger

to the
selects the product of the number m of .reflections of the beam

from the reflective surface '3 and twice the angle between the

area 2 ■

Entrance 'and the Keflexionsfläche 3 des- prism 1

Such a concentrate or can be a spatial transmission hologram with a similar effect on the entry surface 2 exhibit. In this embodiment the concentrator results

the
higher degrees of concentration for light radiation and a narrower range of concentrated radiation compared to the. in Fig. 2 shown concentrator. This is due to a smaller area of the exit surface 4 ′ and to a larger angle between the reference bundle 6 and the object bundle 7.

The sunbeam concentrator shown in Fig. 4 contains a prism f 'in the form of a parallelepiped and a material layer 5 with a spatial passage holoRram on the entrance surface 2. The diffraction grating of the said hologram is through a plane-parallel yeast bundle 6 and a divergent object bundle 7 formed of radiation. There-

O 1 4 I / OO

- 26 -

by that the diverging object bundle 7 in the manufacturing

1"

Operation for the concentrator in the prism at a total reflection angle has been headed, is introducing a

6th
the reference bundle of identical beams from the air into the optically denser medium of the prism at an angle of total reflection. This is a necessary but not a sufficient condition for the concentration of light radiation. The light beam diffused on the spatial hologram

1"

enters the prism at the angle of total reflection, suffers a total reflection on the reflection surface 3 and kehrb. at some point into the material layer 5 with the spatial Hologram back. For concentration, it is sufficient that the beam after reflection from the interface is a spatial hologram / Air the Bragg condition on this section of the hologram not fulfilled. Then he will not diffuse on the spatial hologram and the exit surface 4- after a series of ^ Leave total reflections. For this purpose, the structure of the diffraction grating of the spatial hologram is in the direction of propagation of the repeatedly reflected beam is inhomogeneous. This inhomogeneity is caused by the divergence of the object bundle 7 ensures its rays "in the formation of the hologram in the material layer 5 at different angles enter.

By choosing the distance from the source P (Fig. 4) forTbbjektbündel 7 up to the entrance surface 2 and the distance between the entrance surface 2 und.der reflection surface 3 is the incidence of the from the hologram / air interface

reflected beam onto the hologram with such an angular

deviation from the Bragg angle on this section allows, that the diffraction effectiveness of the spatial hologram on this section is zero for him. Since the spatial hologram has an angle selectivity, it does not exercise any diffusive effect on the strati directed with a certain angular deviation from the Bragg angle.

Depending on the geometry of the diverging Object bundle with a given wavelength can be the light radiation in the manufacturing process for the concentrator on two and more exit faces of the prism ι on part of the Exit surface or concentrated on any point on the prism will.

The embodiments shown in FIGS. 5 and 6 of Concentrate or s work in analogy to those described above with the only difference that both embodiment according to Fig. 5 shows the radiation from the two holograms - the Transmission hologram (layer 5) and the ßeflexionshologram (Layer 5 ') - on the one exit surface 4 and in the embodiment according to FIG. 6, the radiation from each layer of the transmission hologram onto a corresponding exit surface 4 or 4 'is concentrated.

. Because the spatial hologram in addition to the angular selectivity also possesses a spectral selectivity, its diffraction effectiveness decreases with the deviation from the Bragg wavelength with lighting below the Bragg angle. In all of the sunbeam concentrators described above, instead of the more detailed spatial hologram, a single-sided hologram Hologram of sufficient thickness used. will. The spatial diffraction gratings from different light sources

j 14 ι / sy

rv - - - *

»« VV * ■ *> · * WHW * r - «V * * - *

- 28 -

are superimposed on each other, and when illuminated by white light below the Bragg angle, each diffraction grating separates its own tipectral range. The effect of cross modulation proves to be minimal when the wavelengths of the light sources differ noticeably from one another.

The enumerated embodiments of the solar beam concentrator limit the invention in any way and are illustrative of the variety of possible designs and properties of a new type of fundamentally Sonnenstrahlkonzentratoren based on the use räumlicne ^r holograms, and the effect of the total reflection cited.

The sunbeam concentrator allows it with inventive AuS ^ ^{13 OIb 1} Sa re degrees of concentration compared to the existing concentrators on the basis of a prism with total reflection

to obtain. The manufacturing method according to the invention for the concentrator there is the possibility of using sunbeam concentrators in a wide range of spectral selectivity of narrow-band filter concentrators, with a few Nanometer wide spectral range up to concentrators to obtain which have practically no spectral selectivity. The separate concentration of different spectral ranges on different exit surfaces allows with a concentrator, several selective receivers for a light radiation with maxima of sensitivity at different levels at the same time To use wavelengths. This increases the effectiveness of the concentrator significantly and expands its range of applications en. The concentrator is very simple in construction, has the smallest possible number of components and is

very reliable. Its manufacturing process stands out is characterized by the absence of labor-intensive mechanical machining processes and includes only a small one Number of operations that require little time (approximately a few minutes) to complete.

Claims (12)

Patent spray before T. Sunbeam concentrator in the form of a prism with Surfaces for entry, reflection and exit of rays, characterized, that on the entry surface (2) and / or on the reflective surface (3) a material layer (S) with one produced therein spatial hologram is arranged, which is constructed on the entrance surface (2) of the transmission type and on the reflection surface (3) of the reflection type and in each case in such a way is that the radiation in the prism (1) at an angle of total reflection (Θ) is introduced. 2. Sun ray concentrator according to claim 1, characterized in that that the angle (H ⁷ ') between the entrance surface (2) and the reflection surface (3) is at least half 530- (0802/1-P.86817-M-61) -DfMy 3U1789 Angular deviation from the Bragg angle is the same at which the diffraction efficiency of the hologram is minimal. 3. Sunbeam concentrator according to claim 1, characterized ζ e i chnet, that the parameters of the hologram are chosen such that the radiation in the prism (1) is parallel to the Spreads area that is opposite to that on which the hologram is located. 4. Sunbeam concentrator according to claim 1, with a prism designed in the form of a parallelepipod, characterized, that the spatial hologram has a non-uniform structure to prevent diffraction of a within the Has prism propagating beam, which is reflected from the interface hologram / air. 5. Sun ray concentrator according to one of claims 1 to 4, characterized in that that the spatial hologram is made of multiple layers and each layer contains information about a light source with one of the wavelengths of the light sources used in the generation of the holograms in the other layers en
contains different wavelengths. 6. Sunbeam concentrator according to claim 5, characterized in that that the number of layers of the spatial hologram is equal to the number of exit surfaces (4, 4 ¹ ) and the structure of the hologram of each layer is selected taking into account the direction of radiation on the corresponding exit surface (4 or 4 ¹ ). 3U1789 7. Method of making a sunbeam concentrator according to claim 1 with recording of an interference image in a light-sensitive layer of a reference and an object bundle of laser radiation, characterized in that the light-sensitive layer (5) on the entry surface (2) and / or on the reflection surface (3) one Prism (1) is applied and the recording of the interference image takes place by the .Reference bundle (6) in the direction of the radiation to be concentrated. and the object bundle (7) at the total reflection angle θ of Materials of the photosensitive layer (5) and the prism (1) is directed. 8. The method according to claim 7, in which a prism with a trapezoidal base is used, characterized in that the object bundle (7) is a light radiation with a flat wavefront is used and directed at one of non-parallel prism surfaces, which are used as the entrance and reflection surface (2 or 3) can be selected. 9. The method according to claim 8,
characterized, that the entrance angle (Θ) for the reference beam. (7) in the prism (1) is ^{chosen according to the formula θ 1} - β + 2 f "m, where Θ 'is the angle of incidence of the object bundle on the entrance surface (2) of the prism (1), ß the critical angle for total reflection at the prism / air interface, ^ ¹ the angle between the entrance surface (2) and the reflection surface (3) of the prism (1) and m is the maximum number of multiple reflections of a beam of radiation to be concentrated within the Prism (1) called. 10. The method according to claim 7, in which a prism with a rectangular base is used, characterized in that the object bundle (7) is a light radiation with a diverging wavefront is used, the source (P) of which is arranged in such a way that a section on the Hologram / air interface between the point of entry of a ray and the point of its first reflection from the hologram / air interface at an angle not less than the angular deviation from the Bragg angle is visible at the point of the above-mentioned first reflection, at which the diffraction efficiency of the spatial hologram is minimal. 11. The method according to claim 7,
characterized, that on the first photosensitive layer, at least Another photosensitive layer is applied and an interference image is recorded on each of the layers is, including from a light source with one of the wavelengths for recording the interference images on the Other layers used light sources of different wavelengths and the values of the wavelengths chosen for all light sources taking into account the absence of the effect of cross modulation will. 12. The method according to claim 11,
characterized, that the number of layers of the spatial hologram according to the number of exit surfaces of the concentrator is selected and an interference image is recorded in each slice by moving the object beam (7) towards is directed to an exit surface corresponding to the respective layer.