FR2534430A1 - LIGHT EMITTING DEVICE - Google Patents

Abstract

THE INVENTION RELATES TO AN ELECTROLUMINESCENT DEVICE. IN THIS DEVICE CONTAINING AN ELECTROLUMINESCENT ELEMENT 5 AND A FIBER 8, RECEIVING THE LIGHT EMITTED BY THE ELEMENT 5, THESE TWO ELEMENTS BEING MOUNTED ON A SUPPORT ORGAN 13 JOINT BASE 1-3, OPTICAL FIBER 8 IS MAINTAINED IN A HOLE 20 HOLE IN THE SUPPORT ORGAN, IN A STATE SUCH THAT THE ENTIRE SURROUND IS SURROUNDED BY A FIXING MATERIAL 11. APPLICATION IN PARTICULAR TO LASER DIODE AND FIBER OPTIC DEVICES, PRESENTING A VERY HIGH EFFICIENCY OF OPTICAL COUPLING BETWEEN LASER DIODE AND OPTICAL FIBER.

Description

The present invention relates to an electroluminescent device and more

particularly a device

  laser diodes comprising an optical fiber which is

  for the propagation of light.

  Among the propagation devices of the

  light, such as communications devices,

  For example, a laser module, which uses a single-mode optical fiber and a semiconductor laser chip, is described in the patent application published in the Official Journal.

  in Japan under No. 57-2589 This unit or module in

  ser uses a condenser lens etc for

  perform the photoelectric coupling between the micro-

  laser wafer and optical fiber, and is

complex construction.

  As an optical communications device, the author at the base of the present invention has developed

  previously a diode laser device

  carrying an optical fiber having a structure such

  shown in Figures 1 to 3 annexed to the first

  This device forming a laser diode

  does not include a condenser lens, etc.,

  between a laser microplate and an optical fiber and is characterized by a simple arrangement as well as

  a small size This device is assembled on the

  of a rod 1 made in the form of a plate ai-

  The rod 1 is such that a surface of an elongate metal plate is cut to form an annular sealing wall 2 in the central portion of said plate, and that the inner side of the sealing wall of annular form 2 is further hollowed out, which makes it possible to form a portion 3 in the form of a foot or pedestal in the lower part of the cavity A support 4 is fixed on the

  base-shaped part 3 via a weld

  re, and a laser diode chip 5 is fixed to this support by means of a solder. At both ends of the rod 1 there are provided respective guide holes 6 and 7 extending towards the exit faces of the microplate.

  5, through which the laser radiation

  de-fiber 9, wherein an optical fiber 8 is inserted and fixed in a centered position and in a closely adapted manner, is mounted in a guide hole 9 and is fixed to the rod 1 by means of a silver paste The front end of the optical fiber 8 is opposite an exit face of the chip 5, so as to receive laser radiation itself. FIG. 3 is a view showing, to a larger extent scale, the shaped part of

  fixed point of the optical fiber As is

  In this figure, the tip-shaped portion of the optical fiber 8 is attached to the base portion 3 of the rod 1 by means of a fastening material 11 such as a

  resin or solder, so that the yield of recep-

  of light in the optical fiber 8 (efficiency of

  optical coupling) does not vary under the effect of vibrations.

  With regard to single-mode fiber which has a nucleus

  With a diameter of about 8 microns, it is necessary to carry out

  of the optical axis of the optical fiber 8 on the

  before the latter compared to the microplate-

  5, with a precision of, for example, a value of + 0.2 to 0.3 microns, in order to obtain a desired yield.

  optical coupling, suitable for use.

  Moreover, a control fiber 12 is narrowly

  inserted and secured in the other guide hole 7.

  The front end of this control fiber 12 is dis-

  posed opposite the other exit face of the micro-

  plate 5 to control the intensity of the light.

  In addition, two drivers

  (terminals) 13 and 14 are arranged in the rod 1

  13 is a ground conductor, which is soldered to the

  ge 1 and is electrically connected to the lower electrode

  5 of the chip through the intermediary of the

  1 and the support 4 The other conductor 14 is fixed to the rod 1 by means of a glass (insulation) not shown, and its inner end protrudes from a face of end of the rod 1 inside the space inside the wall

  ring-shaped seal 2 The part of the

  The protruding inner unit and the upper electrode of the chip 5 are electrically connected by a gold conductor (wire). In addition, a flat cap 16 is attached in an airtight manner to the

  upper part of the annular shaped watertight

  nular 2 by means of a knurled weld

  re to hermetically encapsulate the chip, etc. The alignment of the optical axes of the fiber and the laser chip in such a laser diode device is performed in such a way that

  position, in which the laser beam emitted by the

  fixed laser crop 5 can be received in the fi

  8 to the last limit, is measured accurately by means of a photodetector, while the optical fiber is displaced, following which

  this fiber is fixed However, the researches

  made by the author of the present invention have

  that regardless of the precision of alignment of

  optical axes of the optical fiber and microplate

  te, the optical axis of the optical fiber shifts after

  its fixation, so that the performance mating-

  or optical transmission decreases.

  As a cause of this phenomenon, it has been found that the front end (optically coupled end) of the optical fiber 8 is displaced downwards as a result of the shrinkage occurring during the firing of the fixing material 11, which shifts the latter by report

at its initial position.

  This case is illustrated in Figure 4

  This figure shows how

  a typical section taken in accordance with the

  Figure I-I of Figure 1 The fastening material, as

  a resin 11 extends downwards from the fiber optics

  tick 8 and pull the fiber down when

  baked (in the figure the directions of the training

  downwards are indicated by arrows).

  Since the magnitude of this downward pull reaches a value such as 0.3-0.4 micron at

  maximum, the optical coupling efficiency decreases

  1 D nue, with the result that the available capacity of use of the laser diode device

  In particular, in the case of a single fiber

  mode, whose core 21 has a diameter of a few microns, it presents itself as a disadvantage, the fact that

  the light can hardly be received.

  An object of the present invention is to provide

  a laser diode device with an optic fiber

  which can maintain a high efficiency of trans-

optical coupling mission.

  This problem is solved according to the pre-

  invention by means of a laser diode device comprising an optical fiber having an optically coupled end which is arranged to be struck by the laser radiation emitted from a laser diode chip exit face, and which is characterized by the fact that said optical fiber is carried in the center of a fastening material formed by

  a resin or a brazing material, which is

  cooked in a throat or hole provided in a

  of support, which has the effect that said fiber

  optics is maintained while being subject to

  radially across its outer periphery.

  Other features and benefits of the

  present invention will emerge from the description given

  Hereinafter, reference is made to the accompanying drawings, in which: FIG. 1, which has already been mentioned, is a plan view, partly in section, of a diode laser device comprising an optical fiber and which has been summer

  previously developed by the author at the base of the pre-

  this invention; Figure 2, which has already been mentioned, is a sectional view taken along the line II-II in Figure 1; Figure 3, which has already been mentioned, shows a sectional view on a larger scale showing a portion of Figure 2; Figure 4, which has already been mentioned,

  is a sectional view taken along the line I-I of the

  Figure 1, to explain the disadvantage of the prior art; FIG. 5 is a plan view, partly broken away, due to a laser diode device comprising

  an optical fiber, which corresponds to a form of reali-

of the present invention,

  FIG. 6 is a sectional view taken

V-V line of Figure 4;

  Figure 7 is a larger sectional view of

  scale showing part of Figure 5;

  Figure 8 is a larger scale view.

  taken along line III-III of Figure 5,

  trant a support part of the optical fiber.

  Figure 9 is a larger sectional view of

  scale showing a support part of the fiber op-

  in a laser diode device with a finite

  optical fiber according to another embodiment of the present invention;

  FIG. 10 is a larger sectional view

  scale showing a support member of the optical fiber

  in a diode laser device having a fiber

  optics, and which corresponds to another form of

  of the present invention; Figure 11 is a perspective view of the support member of the optical fiber shown in Figure 10; and

  FIG. 12 is a perspective view of

  a modified embodiment of the

support of the optical fiber.

  Hereinafter will be described the preferred examples

  res embodiment of the invention.

  Embodiment N 01 A laser diode device according to this embodiment is shown in FIGS. 5 to 8 This diode laser device is assembled from an elongated metal rod 1, similar to the laser diode device of FIG. prior art shown in Figures 1 to 3 The rod 3 is such that a surface of an elongated metal plate is cut so as to form an annular-shaped sealing wall 2 in its central part, and that the inner side of the annular sealing wall 2 is hollowed out more deeply so as to form a base-shaped or foot-shaped part 3 at the center of the lower part of the cavity.

  4 is attached to the base portion 3 by the

  a solder and a diode chip

  laser 5 is fixed on this support by means of a weld.

  At both ends of the rod 9, there are provided respective guide holes 6 and 7 extending towards the exit faces of the chip 5, through which the laser radiation exits a fiber guide 9, in which the optical fiber 8 is inserted and fixed in a centered position and in a closely adapted manner, is mounted in a guide hole 6 and is fixed to the rod 1 by means of a silver paste. optical fiber 8 is disposed facing an outlet face of the crop half 5 so

  that this optical fiber 8 receives the laser beam.

  As illustrated in FIG. 7, the front end (optically coupled end) of the optical fiber 8 penetrates a hole 20 in a support member 19 projecting from the pedestal portion 3 of the rod. 1 and is

  attached to this support member 19 by means of a material

  fixing material 11 such as a resin or weld

  re, so that the light receiving efficiency in the optical fiber 8 (optical coupling performance) does not vary under the effect of vibration In addition, the core 21 of the optical fiber 8 in this

  embodiment has a diameter

  5 and 10 microns. Apart from this, the upper part

  the upper part of the support member 19 forms a surface

  oblique 22 so that the fastening material 11

  by the resin or the brazing material may be

  easily introduced into the hole 20 having a diameter

  In addition, the element of the pedestal-shaped part inside the support member

  19 is provided with a flow recess 23 which

  width of 0.5 mm and which receives and circulates

  ler the fastening material 11 which has overflowed the hole

  through circular 20 This is why the faces of ex-

  the end of support 4 and chip 5 can not

  not be covered by the fastening material

  11 having overflowed from hole 1 and the reception of

  Laser 18 is not hindered.

  Moreover, the control fiber 12 is

  The front end of this control fiber 12 is disposed opposite the other exit face of the chip 5 so as to control the intensity of the laser light In addition, two-conductor

  13 and 14 are arranged in the rod 1.

  13 is a lead conductor, which is welded to the

  rod 1 and which is electrically connected to the electro-

  of the lower part of the chip 5 via the rod 1 and the support 4 The other conductor 14 is fixed to the rod 20 via a glass (insulation) not shown, and its inner end -made protruding from an end face of the stem

  1 in the space inside the annular wall

  sealing strip 2 The inner end and the elec-

  upper trode of the chip 5 are connected

  electrically by a conductor (wire) 15 made of gold.

  In addition, a flat cap 16 is mounted in an airtight manner on the upper part of the annular sealing wall 2 by means of a weld at the

  wheel, so as to hermetically encapsulate the

  cropplate 5, etc. When assembling such a laser diode device, after the optical axes of the chip 5 and the optical fiber 8 have been aligned, the fastening material 11 is introduced into the hole 20 that the traveroe the optical fiber 8-, and is baked As shown in Figure 8, the optical fiber 8 thus extends along the axis of the hole

  and all of its outer circumference is suppor-

  uniformly by the fastening material 11.

  Therefore, even when cooking withdrawal

  of the fastening material 11 has begun, the fiber optic

  that 8 is subject, on the whole of its outer circumference

  less than uniform traction along the directions

  radial and is fixed without any modification of its

  position corresponding to the alignment of the optical axes, so that the performance of the optical coupling for

  the optical fiber 8 and the chip 5 can be

  This is why we can make

  the laser diode device with good optical coupling efficiency, and with a high percentage available. Embodiment N 12 The present invention is not limited to

  For example, as shown in FIG.

  shown in FIG. 9, the support member 19 serving to

  support the optical fiber 8-is provided with a groove or rai-

  Nure 24 and the optical fiber 8 s', extends along the axis

  this groove 24 and all of its outer circumference

  is supported by the fixing material 11 inserted

  in said groove Thus, as in the previous embodiment, the optical fiber 8 is fixed

  while maintaining the alignment state of the optical axis.

Embodiment N 03

  As shown in FIG.

  (thin slot) and a hole 25 extending

  said slot, can be provided in the support member 19 for supporting the optical fiber 8, and the latter can extend along the axis of the

  hole 26 so that the whole of its outer periphery

  be supported by a fastening material 11

placed in this hole.

  As can be seen in the figure, we give

  at the slot 25 a width W less than the diameter of the hole 26 As in the case of embodiment 1,

  the entire outer periphery of the fiber optic

  8 is therefore subjected to uniform traction in the radial directions and can be fixed without

  that the alignment position of the optical axes does not vary.

  This embodiment has the advantage that the fastening material 11 for fixing the optical fiber 8 can be injected efficiently.

  from the thin slot 26 into the hole 25.

  The external appearance of the support member 19 shown in FIG. 10 is such that the notch

  made in one piece with hole 26 is

  as shown in FIG.

  The support member 19 may be all-to-

  makes a structure having an orifice 27 for injecting the fastening material, as is

shown in Figure 12.

  It must be added that when one gives to the

  W width of the slot 25 a width greater than the diameter

  optical fiber 8, this optical fiber can

  be advantageously introduced into the hole 26 by the in-

  the slot 25 during the assembly operation.

  of the laser diode device In addition, the slot

  25 can of course be provided in the part la-

  side of the support member 19 and not in the

superior of the latter.

  As indicated above, in accordance with

  In accordance with the present invention, it is possible

  laser diode positive comprising an optical fiber, suitable

  maintain a high optical coupling efficiency.

  The present invention is applicable to

  light-propagating device using a

  for audio systems and communica-

  tions and has the greatest effectiveness when

  laser diode devices having a monomode optical fiber having a small diameter core.

Claims (6)

  1 Electroluminescent device, in the   which an electroluminescent element (5) and an   optically coupled, of an optical fiber (8) serving   to receive a light emitted by the electroluminescent element (5) are contained in a sealed box   identical (2), characterized in that said fiber optic   that (8) is held in a groove (24) or hole (20) in a support member (19) for supporting said fiber in a state in which the entire periphery of the fiber is surrounded by a fastening material (11).   2 Electroluminescent device, in particular   Laser diode arrangement, comprising an optical fiber (8)   whose one end, optically coupled, is   laser-emitted from an output face of a laser-diode chip (5), characterized in that said optical fiber (8) is supported in a groove (24) or in a hole ( 20) formed in a support member (19), and in a state in which the entire periphery of the fiber is surrounded by a material of fixing (11).   3 Electroluminescent device, in particular   laser diode, comprising an optical fiber (8)   according to claim 2, characterized in that the material   fixing material (11) is constituted by a resin or a welding material.   4 Electroluminescent device content   in a light propagation device,   carrying means (1) for light emission, a   optical fiber (8) which transmits light from   so-called means of light emission, and an organ of   support (19) which supports said optical fiber (8),   characterized in that said support member (19) comprises   carries a through hole (20,26) through which the optical fiber (8) extends and wherein the latter is   supported by a fastening material (11).   An electroluminescent device as claimed in Claim 4, characterized in that a slot (25), which continuously extends said through hole (26) and serves to inject said fastening material (11) along said hole, is provided in a higher part said support member (19).   6 Electroluminescent device according to the   claim 5, characterized in that the width (W) of said slot (25) is smaller than the diameter of said hole through (26).   7 Electroluminescent device according to the   claim 4, characterized in that an orifice (27), which continuously extends said through hole (26) and serves to inject said fastening material (11), is provided in an upper part of said member support (19).