DD148390B1 - ARRANGEMENT FOR INPUTING LIGHT IN A LIGHT GUIDE - Google Patents

Description

For this 1 page drawings

field of use

The invention relates to an arrangement for coupling light from a light guide into another light guide, wherein at the same time the use as an attenuator, branch element or crossover in the optical communication or measurement technology is possible.

Characteristic of known technical solutions

Arrangements for coupling light from one light guide to another are known.

In DE-OS 2655114 rod lenses are used for coupling and coupling of light in optical fibers. Between the rod lenses then damping discs, interference filters or splitter mirrors are arranged.

Also, the use of individual concave mirrors for coupling into optical fibers has been proposed, wherein in the free space between the optical fiber end faces and the concave mirror, for example, a measuring zone for measuring vapor absorption is provided or damping discs, splitter or interference filters are arranged.

The known arrangements have the following disadvantages for the optical communication technology.

Stablinsenanordnungen require a very high adjustment effort of the light guide with respect to the rod lenses on the one hand and with respect to the Stablnsen each other on the other hand. The aberrations of the lenses also cause loss of attenuation, which can be eliminated only by the very complex production of aspherical surfaces.

Although concave mirror assemblies have at achsnaher position of the optical fiber smaller Figure losses, however, the two light guide ends with high precision in the three spatial directions with respect to the concave mirror are positioned there mÖssen, since the stability of this positioning over a wide temperature range (-25 ⁰ C to +55 " C) must be constant The reflection coating of the concave mirror is also not protected against atmospheric influences.

Object of the invention

The object of the invention is to provide an arrangement for coupling light from one light guide into another light guide, in which a concave mirror is an integral part of the light transmission and coupling medium and a high quality of the coupling is achieved.

Essence of the invention

The invention has for its object to couple light from a light guide into another light guide so that optimal Einkoppelverhältnisse and high temperature and time stability are ensured with the simplest adjustment of the optical fiber end surfaces in one plane.

This object is achieved in that the close together lying in a plane end surfaces of two optical fibers are firmly connected to an optically transmissive body whose end faces of the light guide opposite surface has spherical shape, provided with a light-reflecting coating and that a distance between the end surfaces of the two light guides and the apex of the curvature of the spherical surface of the optically transmissive body is equal to the radius of curvature of the spherical surface.

For use as an attenuator, branch element or crossover, the spherical surface of the optically transmissive body is followed by a second optically transmissive body whose spherical surface of the first translucent body opposite surface is formed spherical or aspherical. The reflective coating is then partially permeable and / or frequency-selective.

The arrangement of the end faces of the light guides at a distance from the apex of the curvature of the spherical surface optimum coupling ratios and a high efficiency with high independence from the environmental fines temperature and dirt are achieved.

embodiment

The invention will be explained in more detail with reference to the drawing reproduced embodiments. In the drawing show:

1 shows a schematic section through the arrangement according to the invention, which also acts here as an attenuator, Fig. 2 shows a schematic section through the inventive arrangement in an expanded form.

In Fig. 1, two closely spaced light guides 1; 2 with their end surfaces 5; 6 is cemented to a square surface of, for example, cuboidal glass body 3. The glass body 3 is provided at the opposite end with a spherical braid, which has a reflective coating 4. Spherical surface and coating 4 act as a concave mirror. The distance between the optical fiber end faces 5; 6 and the apex of the curvature of the spherical surface is equal to the radius of curvature of the spherical surface.

Light emerging from the light guide 1 propagates conically in the glass body 3 and is reflected on the reflective coating 4 in such a way that this light is coupled into the light guide 2. The same applies to the light from the light guide 2, which is coupled into the light guide 1. The degree of coupling is determined substantially only by the reflectance of the pad 4, so that, for example, at 50% reflection, the arrangement acts as a 3 dB attenuator. The adjustment is carried out by changing the reflectance of the reflective coating 4. The still passing through the reflective coating 4 light can be registered by a photosensitive device and evaluated for measurement purposes.

If the reflective coating 4 is frequency-selective, the arrangement operates as a crossover.

Fig. 2 also shows two light guides 1; 2, whose end faces 5; 6 are cemented to a glass body 3 according to FIG. 1. Since it is necessary in certain cases to parallelize the light passing through the reflective coating 4 or to direct it to other optical fibers or optoelectronic components, the spherical surface of the glass body, however, for the light from the optical fibers 1; 2 acts aplanatisch, that is, neither collects nor eerstreut, a second of the spherical surface of the glass body 3 adapted glass body 7 is disposed of the first glass body 3.

The second glass body 7 may be provided with a spherical or aspherical surface whose radius of curvature is dimensioned so that the light passing through the lining 4 is parallelized or focused.

Documents considered:

AT 350811 (G 02 B, 5/14)

Dr. Helmut Naumann

"Optics for Designers" 2nd Edition 1960

Wilhelm Knapp Verlag Dusseldorf

Brockhaus ABC of optics 1961 VEB F. A. Brockhaus publishing house Leipzig

Claims (5)

claims: 1. Arrangement for coupling light from a first light guide into a second light guide, in which a body of optically transmissive material is used as a light transmission and coupling medium whose surface opposite the coupling surface has a spherical shape and is provided with a reflective coating, characterized in that the end faces (5; 6) of two light guides (1; 2) are fixedly connected to the coupling surface and a distance between the end faces (5; 6) of the two light guides (1; 2) and the apex of the curvature of the one with a reflective coating (4) provided spherical surface of the optically transmissive body is equal to the radius of curvature of the spherical surface. 2. Arrangement according to claim 1, characterized in that the reflective coating (4) is partially permeable. 3. Arrangement according to claim 1, characterized in that the reflective coating (4) is formed frequency selective. 4. Arrangement according to claim 1 and claim 2 or 3, characterized in that the reflective surface with a (4) provided spherical surface of the optically transparent body, a second optically transmissive body is arranged downstream of the spherical surface opposite surface is formed spherically. 5. Arrangement according to claim 1 and claim 2 or 3, characterized in that the with a reflective coating (4) provided spherical surface of the optically transparent body, a second optically transmissive body is arranged downstream, the spherical surface of the opposite surface is formed aspherical.