FR2526961A1 - DEVICE FOR CONNECTING AN OPTICAL RADIATION GENERATOR AND AN OPTICAL WAVEGUIDE - Google Patents

Abstract

DEVICE FOR CONNECTING AN OPTICAL RADIATION GENERATOR AND AN OPTICAL WAVE GUIDE. THE DEVICE INCLUDES, BETWEEN GENERATOR 1 AND WAVE GUIDE 12, A TRANSPARENT BLOCK 4 EQUIPPED WITH A CONVEX FACE 8 WITH RADIATION INPUT AND A CONCAVE EXIT FACE 9 WITH LOWER SECTION, SO AS TO FORM AN AFOCAL SYSTEM. APPLICATION TO THE COUPLING OF A LASER GENERATOR TO AN OPTICAL FIBER.

Description

Device for connecting an optical radiation generator and a guide

  The present invention relates to a device for connecting a

  optical radiation generator and optical waveguide.

  We know a device of this type, comprising, aligned on a

  same axis, a laser beam emitter and a converging optical

  able to concentrate the beam on the input of an optical fiber.

  This device has drawbacks Indeed, it requires a precise adjustment of the distance between the optical system and the input of the fiber On the other hand, the laser energy distribution in the area

  Beam concentration depends on this setting.

  The present invention aims to overcome these disadvantages.

  It relates to a device for connecting an optical radiation generator and an optical waveguide, comprising the optical radiation generator, means for concentrating the radiation

  and the optical waveguide arranged to receive at one of its extremes

  concentrated radiation, characterized in that said means for concentrating the radiation are constituted by a block transparent to said radiation, the outer surface of said block comprising a first and a second opposite curved face, respectively convex and concave, the first face, plus large that the second face, being arranged to receive the optical radiation along a parallel input beam, the curvature of the first face being determined so that the input beam refracted in the block is focused on the second face, the curvature of the second face being determined so that the concentrated beam exits the block through the second face along a parallel output beam, the section of the output beam being smaller than that of the input beam, so that the output beam

  can fully enter the waveguide through the said end.

of the guide.

  Particular embodiments of the subject of the present invention are described below, by way of example, with reference to the accompanying drawings, in which FIG. 1 shows in longitudinal section an embodiment of the device. according to the invention

  and FIG. 2 is a view in space of another embodiment of

  tion of the device according to the invention.

  In FIG. 1, a laser emitter 1 emits a parallel beam 2 along an axis 3. A cylindrical laser-transparent block t, centered on the axis 3, is arranged on the path of FIG.

  beam 2 Block 4 comprises two elements 5 and 6 constituted respectively

  two materials having different optical properties: for example, these materials may have different refractive indices, different dispersions or both refractive indices and different dispersions. The elements 5 and 6 are bonded one to the other. on the other according to a junction surface 7 A base of the outer surface of the block 4 comprises a convex curved face 8, for example spherical, centered on the axis 3 through which the beam 2 enters the block The other base of the outer surface of the block 4 comprises a concave curved face 9, also spherical, opposite the face 8 and centered on the axis 3 The beam 2 is refracted in the block 4 according to a convergent beam 10 which concentrates

  the laser energy on the face 9, of dimension smaller than the face 8.

  The curvature of the face 9 is determined so that the beam 10 leaves the block 4 in a parallel beam 11 of smaller section than the beam 2 The input face 13 of an optical fiber 12 is centered on the axis 3 in order to receive the beam 11 The diameter of the beam 11 is less than or equal to that of the fiber 12, so that

  this transmits all the laser energy.

  Block 4 thus constitutes a compact afocal optical system. The realization of this block in two elements of different properties adhering to each other makes it possible to correct any aberrations.

chromatic or geometric.

  It is clear that the operation of the device is not affected by a displacement of the block 4 along the axis 3 between the emitter 1 and the fiber 2 Moreover, such a displacement does not cause any variation in the transverse distribution of laser energy in

the beam 11.

  In FIG. 2, a semiconductor laser emitter 14 has a transmitting surface 15 in the form of an elongated rectangle. In this case, the transparent block has the shape of a thin parallelepiped 16. The laser radiation (not represented) of the transmitter 14 enters the block 16 by a convex face 17 disposed opposite the emission surface 15 of the laser 14 The exit face 18 of the radiation is concave As can be seen in the drawing, the faces 17 and 18 are arranged on two opposite sides of the large section of the block 16 The radiation beam exiting the block 16 has a generally parallelepipedal shape so as to enter completely through the

  end section of a flattened waveguide 19, also of parallel shape

  lélépipédique. Of course, the present invention is not limited to the embodiments described and shown which have been given by way of example. In particular, it is possible without departing from the scope of

  the invention, to replace certain technical means by equitable means

  This is how the transparent block can be formed of a single glass or comprise more than two glasses of optical properties

  In addition, curved surfaces 8 and 9 can be aspherical

c.

-4-

Claims (6)

  1 / Apparatus for connecting an optical radiation generator and an optical waveguide, comprising the optical radiation generator, means for concentrating the radiation   and the optical waveguide arranged to receive at one of its   mite concentrated radiation, characterized in that said means for concentrating the radiation are constituted by a block (4) transparent to said radiation, the outer surface of this block comprising a first (8) and a second (9) opposite curved faces, respectively convex and concave, the first face (8), larger than the second face, being arranged to receive the optical radiation in a beam   (2) parallel, the curvature of the first face being deter-   the refracted input beam (10) in the block (4) is concentrated on the second face (9), the curvature of the second face being determined so that the concentrated beam exits the block through the second following face a parallel output beam (11), the section of this beam being smaller than that of the input beam, so that the output beam can enter completely   in the waveguide (12) through said end (13) of the guide.   2 / Apparatus according to claim 1, characterized in that the transparent block (4) comprises a plurality of elements (5, 6) adhering to each other, these elements being formed of materials having optical properties different.   3 / Apparatus according to claim 1, characterized in that the block is of cylindrical general shape, the first and second faces   curves (8, 9) being arranged on the bases of the cylindrical block (4).   4 / Apparatus according to claim 1, characterized in that the block (16) is parallelepiped and thin, the first and second curved faces (17, 18) being arranged on two sides   opposite of the large section of the block.   Device according to Claim 1, characterized in that the input beam (2), the first and second faces (8, 9) and the said   end (13) of the waveguide are centered on the same axis (3).   6 / Apparatus according to claim 5, characterized in that the   first and second curved breeds (8, 9) are spherical.   7 / Apparatus according to claim 1, characterized in that the generator (1) is a laser transmitter, the waveguide being an optical fiber (12) 1