DE2717875A1 - LIGHT GUIDE SWITCH - Google Patents

Description

J.C. Greenwood-2 7 LIGHT GUIDE SWITCH

The invention relates to an arrangement for switching light that propagates in a light guide.

The invention will now be explained in more detail with reference to the drawings, for example.

Show it:

1 shows a cross section through an optical Switch in closed or on state;

Fig.2 shows the switch according to Fig.1 in its open or off state and the

Fig. 3 and 4 cross sections of fiber optic switching matrices

for use in a circuit arrangement for "n out of m coding".

709846/0787

J.C. Greenwood-2 7

The switch according to FIGS. 1 and 2 contains an elongated one Holding part 11 with a V-shaped groove 12, the surface of which is covered with a layer 13 of transparent material is. The holding part 11 holds a bare light guide 14 in its V-shaped groove 12. The transparent layer 13, which can be made of a plastic material has an index of refraction that is significantly smaller than that of the light guide 14, so that it keeps the light losses due to light emission from the light guide 14 to a minimum. In In some applications, the surfaces of the V-shaped groove 12 can be polished very well, so that on the layer can be dispensed with.

The V-shaped groove 12 is bridged with a light-absorbing elastic membrane, for example made of polyurethane, and immediately above this membrane 15 a push button or button 16 is attached. By pressing the Push button 16 deforms the elastic membrane 15, as shown in Fig.2, and is with the bare surface of the light guide 14 brought into contact so that the light propagating along the light guide 14 is strong is dampened.

3 shows a schematic cross section of a Optical fiber switching matrix in which the principle of the optical switch shown in FIGS. 1 and 2 is used. A flat base plate 31 is covered with a layer 32 of transparent material with a relatively small refractive index overdrawn. On layer 32 is an array of

709846/0787

J.C. Greenwood-2 7 Light guides 33 applied with a relatively large refractive index.

At various points along the shown direction of extent of the switching matrix there are certain under the light guides 33 selected light guides are provided with a coating 34 made of a material with a relatively low refractive index, such as shown in Fig.3. An elastic light-absorbing membrane 35 is attached above the arrangement of light guides 33, with the help of switching bars 36, which are essentially parallel to one another and perpendicular to the light guides 33 are arranged, can be moved so that it comes into contact with the light guides. By pressing any the switching bar 36 becomes the corresponding part of the membrane 35 in contact with only those of the light guides 33 brought, which are not coated in this area with the material 34 with a low refractive index. Thus, the Arrangement according to FIG. 3 a switch for "n from m coding".

A plastic material can advantageously be used both for the layer 32 and for the light guides 33, wherein the light guides 33 are applied by means of a lithographic mask.

The fiber optic switching matrix shown in Figure 4 is similar that shown in Figure 3, but the parallel light guides 41 are bare along their entire length. A flexible one The membrane 42, which is located above the light guide 41, is brought into contact by means of an arrangement of switching bars 43 brought with selected light guides. For this purpose, each of the switching bars 43 contains recesses 44, which correspond to the to be generated code are arranged.

709846/0787

Blank page

Claims (5)

Dipl.-Phys. Leo Thul Stuttgart J.C. Greenwood-27 INTERNATIONAL STANDARD ELECTRIC CORPORATION, NEW YORK claims 1. Arrangement for switching light that propagates in a light guide, characterized in that a holding part (11) for holding the bare light guide (14) is provided, which affects the light propagation only insignificantly, and that means are provided to one Part of the surface of the light guide (14) to be brought into contact with a light-absorbing material (15) in such a way that the light propagating in the light guide (14) is attenuated. 2. Arrangement according to claim 1, characterized in that the holding part (11) has a groove with a V-shaped cross-section in which the light guide lies (Fig.1, Fig.2). 3. Arrangement according to claim 2, characterized in that the holding surfaces (12) of the groove are coated with a transparent material (13) with a relatively small refractive index. 4. Arrangement according to claim 1, 2 or 3, characterized in that the light-absorbing material (15) is an elastic membrane made of polyurethane which is attached to the light guide (15) opposite to the holding part (11), and that a push button arrangement (16) is provided, by means of which the membrane (15) can be brought into contact with the light guide (14). Kg / lap April 18, 1977 7098A6 / 0787 ORIGINAL INSPECTED 27Ί7875 J.C. Greenwood-27 5. Arrangement according to claim 1, characterized in that the holding part (31) has a flat surface which is coated with a layer (32) with a relatively small refractive index, on which several light guides (33) with a relatively high refractive index are arranged in parallel are that the light-absorbing material is an elastic membrane (35) which is fastened opposite the light guides (33), that several mutually parallel switching bars (36) are provided which run perpendicular to the light guides (33), that each light guide (33 ) is provided on a selected section with a protective coating (34) made of material with a low refractive index, the switching bars and the sectional protective coatings (34) of the light guides (33) being arranged in such a way that when one of the switching bars (36) is pressed, the elastic membrane (35) comes into contact with only the light guides that have no protective coating in this area, so that an n-out-of-m code can be represented i st (Fig. 3). 709848/0787