DE2151781C3 - Process for the production of light guide systems - Google Patents

Description

Mesh on its free surface with an optical dimension are required,

insulating layer is coated. This task is based on a procedure

6. The method according to claim 5, characterized in that it is of the type mentioned at the outset draws that the partial removal of the crystal dissolved that a network consisting of a polymer layer is made by means of etching. with the fiber optic system to be produced

7. The method according to claim 5, dadurci, characterizing structure on at least one layer of eizeichnet, that the crystal layer is applied in preformed no other polymers.

Grooves of the substrate is grown. 4 ° By using according to the invention

8. The method according to claim 1, characterized in that organic polymers are used as starting materials draws that the network by exposure through a very large difference between the widths corresponding Pattern and subsequent correspondence indices of the light guides on the one hand and the optiwinds and fixation is obtained. see insulators on the other hand, so that the invented

45 properly manufactured licitleitersysteme a very

Enable low-loss light transmission. About it

In addition, it is suitable to use the method according to the invention in

The invention relates to a method of manufacturing to a high degree for mass production, with prak-

in an optically isolating environment with andetisch any desired guidance of the individual light

rem optical refractive index and other fusible conductors 50 is possible within the light guide system. in the

or softening temperature embedded light guide- end result thus leads to the inventive method

systems made from one polymer. drive with little effort and expense

In the course of efforts to use high-quality fiber optic systems that

Optical fiber systems for message transmission are excellent for the purposes of

optical communication arises in constantly increasing 55 optical communication.

Measure the need for simple and cost-effective design and development of the

gen manufacturing process for such light guide systems. The method according to the invention are in subclaims

The original light guides are individually marked in the form of glass fibers,

bundle are for the purposes of optical message- In the following description of / Visfüh-

For cost reasons only conditionally suitable examples for the production of the light guides and

net, and so there has been no lack of experiments, the invention becomes more detailed with the aid of the drawing

to develop fanned fiber optic systems, which is explained in detail. Here shows

special inexpensive mass production Fig. La and b a branched light guide, the

by applying a light-emitting substance to a

These efforts so far have been a complete success. 65 plate has been produced;

However, it was not decided, since FIGS. 2a, b, c and d, which were developed in the process, show the cross section of a light guide

Light pipe systems are either still too expensive with improved optical isolation as well as various

or, in terms of their optical performance, not stages of its production;

3a, b, c and d show different stages in the production of a light guide arrangement by etching;

4a, b, c, d, e and f show different stages of manufacture of a light guide device with a multilayer Arrangement of light guides;

5a, b, c and d show different stages in the manufacture of light guides with a predetermined cross section;

6a, b and c different stages in the manufacture of spatial Jicht conductors;

7a, b, c and d show a different manufacturing variant for spatial light guides;

FIGS. 8a, b and c show different stages in the manufacture of light guides with larger dimensions;

9, 10 and 11 different variants of the method for the production of hollow light guides;

FIGS. 12a and b show a multilayer light guide;

13a and b show a method for producing light guides using a model;

14 and 15 illustrate a method of making "printed" light guide assemblies.

Embodiment 1

On a dielectric plate 1 (Fig. La) with a refractive index / I ₁ and a low absorption coefficient (i.e. with transparency conditions), a light-conducting element 2 is applied in the form of a strip (a wire) made of transparent material with a refractive index H ₂ , with / J ₂ > H ₁ . The light-guiding element 2 applied on the basis of a predetermined light-guide sketch thus forms the desired, possibly a branched light guide.

The plate 1, which carries light guides produced in this way (or other glued-on, inserted into cavities or otherwise fastened elements) is completely or partially covered from above with a transparent protective layer 3, the material of which has a refractive index H ₃ , where H. ₃ </ J ₂ is.

The light guides can be applied to the plate as follows. You can choose from a solution or a melt of the substance intended for the formation of a light-conducting strip in the middle one after the other The thickness and the height can be pressed in or poured according to the specified program of the strip depends on the speed with which the strip is pressed in and the casting head is guided by the material viscosity, curing time and the adhesive force. All of these parameters can one can vary within wide limits and thereby a light guide thickness of a few micrometers up to a few Centimeters received.

_{A plate of any thickness and shape made from the mixed polymer polybutyl methacrylate (^ 1} = 1.47) can be used for the production of light guides, the light-guiding strip being made from a solution or a melt of a styrene mixed polymer (// _a 1.59 ) or from a mixture in which the Gewielus parts of components result in the required size of / ;. All polymers of the acrylic and methacrylic series can be used for the process described, as well as for the processes explained below for the production of optical executions, after the substances have been sorted according to their relative refractive indices. To cover the surface of the light guide pattern, one can use the material of the plate or another material with a refractive index which is smaller than that of the light guide strip.

The preprogrammed change in cross-section of the licit conductor strip (or of the fiber optic wire) takes place by changing the casting head speed. A branch can either be made by splitting the Material flow are formed in two branches by z. B. two watering heads, one Strips have poured off, gradually diverging, and in the flow from the outside a separator is introduced that divides it in a given ratio and at a given speed, or one forms a branch by inserting a new wire at a certain point of the indented one Begins to press in the light guide.

When pressing in, the composition of the light guide strip (or wire) can be changed. For example you can find the percentage composition of a mixture of styrene and methyl methacrylate copoiymeren change in the interpolymers chelates of rare earth elements to form Introduce light guide sections that are capable of induced emission, build neodymium atoms into the glass etc.

Embodiment 2

To improve the optical isolation of light guides and / or to reduce their aperture, the light guides can be produced with additional dielectric sheaths which have a refractive index // ', where H ₁ </ j'</ J ₂ . For example, an at least 2 to 5 μm thick strip 5 of polymethylniethacrylate (H ₁ ), which is slightly wider than the light guide, is applied to a plate 4 (/ j ^{1) according to FIG} the styrene mixed polymer (/ J ₂ ) or made of a mixture of styrene-methyl methacrylate copolymers, and this arrangement is from above and in front. The sides are potted in the same way with a methyl methacrylate mixed polymer. This completes the formation of the light guide cover. The entire arrangement can be potted from above with a butyl methacrylate mixed polymer, which forms an outer coating.

Embodiment 3

On a dielectric plate 1 (Fig. 3a) with a refractive index H ₁ , a film is applied which has a refractive index / I ₂ and a thickness of at least several light wavelengths of the spectral range to be used later. A stencil is placed on this film or a mask 7 (FIG. 3b) is dusted on, and areas of the film that are not required are etched away (FIG. 3c). The formed light guide arrangement is covered from above with a protective layer Γ (Fig. 3d) made of a material with the refractive index / I ₁ . Similarly, one can also use multilayer light guides according to FIG. 4a. Make b, c and d. A film 6 with the refractive index n. _{Z is applied to a plate 1} characterized by the refractive index / Z 1, where / I ₂ > / J ₁ is intended to be. A mask 7 is then dusted onto this film, and it is etched. The structure obtained is then covered with a film 6 made of a substance characterized by the refractive index //., Where / i; i - // ". Again a mask 7 'is dusted on and the film is etched. The generated

21 21 781

Lichtleiteranrodnung can with an optically isolating Layer Γ ζ. B. be covered from the same material as in the plate 1.

The initial foils can be produced on the plate in a high vacuum by casting or by dusting the substances mentioned in the description of the first exemplary embodiment. The mask required for etching can be ^{dusted on from Meta 1} .: (E.g. silver, aluminum). Polymers are etched with solvents (benzene, toluene, xylene, their mixtures, etc.) or with glass-dissolving acids (e.g. with hydrofluoric acid, etc.).

Embodiment 4

Optical fibers made of all the substances mentioned can be dusted on a plate serving as a base in a high vacuum through a stencil or poured from openings in the stencil if the substances mentioned do not adhere to the stencil material. Using a different template, other substances can be dusted on or poured, with which the formation of the light guide pattern can be continued. In a similar way, electrically conductive elements can be sputtered onto the plate, thus forming printed electronic and optoelectronic devices. ^{A printed circuit v} .vjrd prepared in this way is doused with optically insulating material from above.

Embodiment 5

Optical arrangements with fiber optic cross-sections that must be precisely adhered to, ζ. Β. with square, triangular, hexagonal or round light guides (Fig. 5a) can be produced as follows: In the as a substrate Serving plate 1 are groove systems 8 with the desired shape and predetermined profile (Fig. 5b) educated. The plate is then filled with the fabric for fiber optic wires watered (Fig. 5c), which fills the grooves. After hardening, the superfluous material is removed, and the finished optical arrangement is thus obtained (FIG. 5c), which is optically isolating from above Coating 3 can be covered (Fig. 5d).

The groove systems can be produced by any method (casting of plates with grooves, impressions, Etching, photolithography, cutting, etc.), whereby plates are made for the formation of the grooves Substances that were mentioned in the description of the exemplary embodiment 1 are used. The filling of Grooves are made, depending on the selected materials, by pouring them in a noble gas atmosphere, in a vacuum, etc., by piling up etc.

Embodiment 6

A matrix 9 (FIG. 6a), the material of which is used, is used for the production of spatial light guides must not have any adhesion with the fabric of the light-guiding element. In the die 9 are Grooves 10 run from the desired profile. For the production of the die you can, for. B. one under Use fabric or glass known from the trade name »Ftoroplast« (Fluovoplast). In the grooves 10 Any copolymer mixtures of the acrylic or methacrylic series or styrene copolymers can be used poured in and pressed by means of a ram 11. The structure formed in the die (Fig. 6b) is then taken out and covered with a thin cover by immersion in a mixed polymer solution. The structure is then brought into a corresponding position in the room and to form an optical insulating layer covered with a light-insulating material. A spatial light guide arrangement is thus obtained.

A light guide or a light guide arrangement can also be produced according to FIG. 7. A strip 13 made of a material with the refractive index H ₂ is punched by means of a die 14 and a punch 15 when the heating is required, in order to obtain the desired profile. The ferfilband 13 'is removed and z. B. coated with a thin shell by immersion in a mixed polymer solution in order to achieve the initial stiffness of the tape. The tape is then cast to form an optical isolator 16 with a light-insulating material which has a refractive index H ₂ , where M _{2 should be} > H ₁ .

Embodiment 7

When producing light guide arrangements and light guides with great length as well as at the transition for a continuous process of fiber optic production one can proceed as follows:

_a . Ribbons with the required thickness are made from a light-conducting and an optically insulating material. These bands are put together so that the band 17 made of a light-conducting material with the refractive index H ₂ lies on the band 18 made of an optically insulating material with the refractive index M ₁ at H ₂ > H ₁ or is arranged between the bands 18 and 19 , which are made of materials with refractive indices M ₁ or H ₃ and serve as an outer shell. The one educated in this way

₃ - "Sandwich" (Fig. 8a) is rolled between not shown profile rollers with a relief pattern that presses the desired light guide systems (Fig. 8b. C) into the strips, or is pressed with a profile stamp. The bands with the thickness of

. _o 2 to 5 μιτι and more can be produced from substances that were mentioned in Ausführungsursgsbeispiel 1.

The initial sandwich can also be made from any optically clear and in a solvent dissolved polymer or from a prepolymer by pouring a non-sticking surface, z. B. a film-like base made of Ftoroplast or polyalkylene terephthalate, through a flat nozzle and can be produced by changing the substances intended for casting. You can also eat a sandwich Establish centrifugation of a polymer on the same support.

In order to improve the adhesion and the necessary softening, the tapes can be treated by the action of heat during their processing. Individual layers can be shielded from one another by a metal foil, metallized by sputtering or chemically (electrolytically with AgNO ₃ , etc.).

Embodiment 8

If the light-conducting wire and its sheath are made of polymers, the heat treatment takes place mutual partial diffusion of the veins and the covering materials. This way, light guides are made produced, which have zones with continuous refractive index change in cross section.

Such a refraction envelope increases the transparency of the system, since it increases the number of

Reflections from the boundary between the core matter and the envelope with inevitable light losses is diminished.

Embodiment 9

One possibility for improving the light-permeable wedge of light guides and light guide arrangements and for cooling them results from the production of hollow light guides. The light transmission is improved in these light guides because the light does not cover part of its path in the light guide in the absorbing medium. The light guides can be cooled by adding a refrigerant, e.g. B. Helium because of its low viscosity, the cavities of these light guides can flow through.

Such light guide systems are manufactured as follows:

A film coating which has a refractive index H _{2 is} applied to the plate 20 (FIG. 9a) with a refractive index H ₁ . One presses grooves that correspond to the arrangement of the light guides (Fig. 9b), and the superfluous outer film areas are z. B. removed by polishing (Fig. 9c). The light guide arrangement produced is coated with successive layers 22 and 23 (FIG. 9d), the refractive indices of which are H ₂ and / J ₃ .

In another embodiment of the method developed according to the invention (FIGS. 10a, b, c and d), the plate 24, the material of which results in _{a refractive index H 1.} Grooves generated. A thin light-conducting layer 25 with a refractive index H ₂ (H ₂ > H ₁ ) is dusted on the walls and on the bottom of the grooves. The unnecessary parts of this layer lying outside the rollers are then removed, and the structure produced is covered with layers 22 and 23, the refractive indices of which are H ₂ and h, respectively, where / ι,> H ₁ .

The light-conducting film can also be pressed into the grooves of the plate, as shown in FIGS. 11 a, b and c is shown. For this purpose, a flat film 25 is placed on the surface of the plate 24 and pressed into the grooves by pressure when heated accordingly. Then the superfluous Remove the film outside the grooves and cover the structure produced, as described above with layers 22 and 23.

After the substances have been applied to panels, the multilayer structure produced must, in all the cases mentioned, be subjected to a heat treatment in an oven or a thermostat. Depending on the duration of the treatment or the change in temperature, the melt cools or volatile components are removed from solutions at different speeds and from different depths of the material. If it is necessary to adjust the diffusion of substances from one component of the system to another in any processing stage, this can be achieved by placing the products in a solvent atmosphere.

All of the methods described in Examples 1 to 9 can be used for the production of Use light guide arrangements in metal matrices. However, if the light guides do not have an additional shell, the light-permeable wedge of such systems is low even with directional reflection.

Such envelopes are easy to derive, however, if the methods described in exemplary embodiments 2, 4, 7, 9 are used.

Embodiment 10

When merging the light guide plates produced with the in I ig. 12 indicated by dashed lines light-guiding elements or when manufacturing new light cable systems on coatings of the already multilayer optoelectronic devices are obtained. Three-dimensional optical Systems can be made as follows:

a) In a merged set of flat systems, transitional conductors are formed by adding z. B. by drilling, melting, etc. in the set produces cavities, which afterwards with a light-conducting material are filled.

b) With the aid of a method described in exemplary embodiment 6, individual Manufactured light guide systems. These systems are then distributed around the room and with a

ao optically insulating material with a lower melting temperature shed.

c) A three-dimensional model (FIG. 13a) is produced which corresponds to the desired shape of the light guide. The model is cast with a substance that does not adhere to the model material and has a refractive index H _1. The model is then removed and the resulting cavities are filled with a substance (FIG. 13b) which is characterized by a refractive index H ₂ .

When performing this procedure using a model, the following substances can be used:
35

a) Ftoroplast- or polyethylene terephthalate fibers with a more precisely cylindrical shape or less Taper with butyl methacrylate copolymers shed. The fibers are then removed and the cavities with methyl methacrylate shed.

b) Polyvinyl alkchol fibers are cast with the same substance and then dissolved in water.

c) Metal threads rubbed in with graphite paste to avoid adhesion are encapsulated with glass. Large metal shrinkage makes it easier to remove the threads, which are also etched away be able.

Embodiment 11

Light guide arrangements can also be produced inside a crystalline material. Be for this purpose in the crystal areas with prescribed dimensions and with a different (larger) refractive index formed and thereby created conditions for the propagation of light.

Embodiments of such arrangements are considered below:

a) A crystal layer of one compound is epitaxial on a crystal of another compound. For example, an epitaxial layer of NaBr is applied to an NaCl crystal genes whose refractive index is greater than that of NaCl. Areas with given shapes so that only light

709 618/169

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conductors remain. This blank is covered from above with an epitaxial layer of NaCl,
b) The blank made of NaCl provided with the required surface pattern is placed in a supersaturated solution of NaBr (or NaCl with additives to ensure a different refractive index n) . The generated monolith with cut-out figures (fiber optic veins) filled with NaBr is immersed in a supersaturated NaCl solution to form a surface coating with a smaller //.

The other additions that are necessary to produce other elements of the light guide arrangement, can be introduced using planar and thin film technology.

Microelectronic circuits and devices can be manufactured inside the The same crystal form the following areas: 1. Areas with active additives, around lasers or similar elements to produce in these areas of the monolith circuit; 2. Areas with pn junctions and the like Structures when the monolith block is made of semiconducting materials; 3. Areas with accessories, which ensure the required electrical conductivity; 4. Areas with accessories that use electroluminescent lamps etc. form.

Embodiment 12

The simplest method / for producing "printed" light guide arrangements consists of the following: A plate 26 made of polymers or of glass (FIG. 14a) with an applied plate is used light-sensitive layer 27. After exposure of the plate through a mask 28 and after development and fixation remain transparent areas on the plate. Is the index of refraction of the plate smaller than the refractive index of the developed transparent layer, so these transparent areas can the photo layer with appropriate choice of their geometric shapes as light guide arrangements serve.

The photosensitive layer can be coated from above with an optical isolator 29 (FIG. 14c) will.

If thick emulsion layers 30 (FIG. 15) are used as the photosensitive element, the No glass underlay. After the mentioned treatment, the photosensitive element becomes in one embedded optical isolator.

A shortcoming of such devices is that their light transmission is low, as the Ref lexior takes place only from the upper and lower light-insulating coating 29 (FIG. 15c).

In addition 5 sheets of drawings

Claims (5)

able to satisfy. For example, on patent claims: p. 499 of ETZ-B, vol. 21 (1970) or on, p. 2059 to 2069 of >> The Bell System Technical Journal ", 1. Method for the production of in an optisch Vol. 48 (1969), 'No. 7, light guide systems from mono-isolating Environment described with other optical 5 lith glass, in which by means of vapor deposition or Refractive index and other melting or spray-on processes or by means of ion exchange softening temperature embedded light guide or ion implantation processes in individual zones systems made from a polymer, resulting in a slight deviation in the refractive index from the characterized in that a value from a poly is valid for the rest of the material will create the existing network with the io to be produced. This deviation in the refractive index The light guide system of the corresponding structure on min- is generally below 1 / so the time At least one layer of another polymer light guide is applied in the material treated in this way. rial zones associated with relatively high losses, st. 2. The method according to claim I, characterized on p. 1048 to 1054 of »1 EbE Transactions on draws that the network in the shift was presented 15 Microwave Theory «, from Dec. 1968 and on formed grooves is introduced. Pp. 1325 to 1337 by »J. of the Optical Society of 3. The method according to claim I, characterized in America ", Vol. 60, No. 10 (Oct. 1970), are further characterized in that a film of an optically isolate light guide is described, in which a thin layer of the polymer and a Foil made from a polymer such as epoxy resin is applied to a single polymer by means of a tool with the »glass plate or is pressed together between two flat light guide systems to be produced according to glass plates. The surface reliefs are pressed onto one another in this way. obtained light guides are suitable for decoupling 4. The method according to claim 1, characterized in that light radiation from optical systems is identified draws that a separately manufactured network is made of practically none because of the fact that it is in two dimensions Polymers between with top layers of 25 table unlimited expansion of the polymer layers another polymer is included. not used for message transmission purposes 5. The method according to claim 1, characterized by light guide systems. draws that on a base a crystal The invention is based on the object of a layer with a large refractive index is grown to show the way in which an inexpensive that this crystal layer except for a mass production of light guide systems with high corresponding network of optical quality can be achieved, as it is for a subsequent is removed again and that this remaining direct optical transmission to a large extent