JPS6320322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible light guide for connection to high power lasers used for example for medical or industrial purposes. A flexible light guide consisting of a light guide fiber, in particular provided with a coating, in which at least one end of the light guide is provided with a metallic, sleeve-shaped holder, into which the light guide runs concentrically. , and to a flexible light guide for use in high-power laser beams, which together with the holder form a flat end face.

These applications require a large number of light guides. The light guide transmits a laser beam power of, for example, up to 100 W to the application location. On the other hand, due to the high efficiency of the light guide, light guides with a single light guide fiber of approximately 0.2 to 0.6 mm in diameter are particularly suitable.

Known light guides of the above-mentioned type are described, for example, in DE 2145921 and DE 2333280. This type of light pipe presents various difficulties, since the coupling must be able to easily replace the laser, the light pipe or the device to which it is connected. When the optical power of the laser beam is high, it is particularly difficult to design the joint points on the laser side of the light guide in such a way that they can be connected to the connection point without risk of destroying the light pipe. A light pipe whose ends are reinforced in a conical shape and placed in a non-metallic material may be heated so much at its ends that the light pipe may break at its connection point if the laser beam spreads only slightly. be. Due to the complexity of the structure itself, known light guides are relatively expensive for transmitting a given amount of power.

The present invention simplifies the construction of the light guide and allows its connection location to be connected to the laser light source without any problems.
The object is to construct a light guide for the above-mentioned purpose. Furthermore, it must be ensured that the laser energy does not leak out at the end faces of the light guide fibers and that destruction of the light guide does not occur.

The present invention solves this problem as follows. That is, the coating of the light guide terminates in the holder at a short distance in front of the end face, and the holder surrounds both the coating and the stripped end of the light guide fiber in a tight fit. The holder has a tapered portion on the side facing the end face and tightens the coating of the light guide over the entire circumference, and the metal of the holder has good thermal conductivity. solve. A further refinement in this case is that the end faces of the light guide and the carrier are polished, and the end faces of the carrier are provided with a mirror lining.

In a further refinement of the invention, the outer diameter of the holder is considerably larger than the diameter of the light guide, and the holder is further provided with a tapered section to which the clamping ring is attached.

In order to dissipate the heat actually occurring at the connection location, according to the invention a further holder made of metal with a high heat capacity accommodates the holder and the clamping ring.

Next, the present invention will be explained in detail with reference to illustrated embodiments.

The light conductor fiber 1 with the coating 2 has a thickness of, for example, 0.2
Consisting of a quartz glass rod with a diameter of ~0.6 mm. A metal holder 3 is attached to the light conductor fiber 1 in line with the end of the light conductor fiber and in a tight fit. This holder ensures perfect centering of the light guide in a coupling device of well-known construction, which is not shown for simplicity of the drawing, and also prevents the light guide from moving when there are various obstacles in the focusing of the introduction laser. This will prevent heating that could destroy the The laser beam emitted via the end face of the light guide fiber 1 reaches the polished end face of the holder 3, which optionally has a mirror lining 4, where it is reflected or absorbed and converted into heat. . Heat is emitted from a further large-area holder 5 which surrounds the device hitherto described. The inner holder 3 is made for this purpose from a material with good thermal conductivity, for example copper, brass, etc., and the further holder 5 is made from a material with high heat capacity, for example aluminum.
For tested embodiments for which the laser power to be connected is 80W, the weight
It has been found that it is effective to combine a holder 3 made of brass weighing 2.5 g with another holder 5 made of aluminum weighing 30 g.

The illustrated coating 2 has a length of about 2 to 3 mm removed at the end on the light introduction side. The holder 3 has a tapered part 6 which also covers the light guide 2.
The entire circumferential surface of the clamp ring 7 is tightened, and a clamp ring 7 is provided around the tapered portion 6. Clamp ring 7
The light guide is fixed in a holder 3, with a further holder 5 exerting a pressure force on the clamping ring 7 and via the tapered part 6 of the holder 3 on the coating or light guide fiber 1.

The advantages of the invention are as follows. Photoconductor fiber 1
requires only relatively simple polishing at its ends, which can be carried out by simple means by bundling the light guides. It is therefore not necessary to particularly strengthen the ends of the light guide, and there is no need for costly processing of the light guide over its entire length. The illustrated holder can be easily attached to inexpensive light guide fibers and relatively high laser powers can also be connected. The new formation of the connection side of the light guide end prevents thermal destruction of the light guide in the event of laser diffusion. It is also possible to replace the joint of the light guide in a short time due to stress or improper handling.

[Brief explanation of the drawing]

The drawings are explanatory diagrams showing one embodiment of the present invention. Reference numbers in the figure: 1... Photoconductor fiber, 2... Coating, 3... Holder, 4... Mirror lining, 5...
...Another holding body, 6...Tapered portion, 7...Clamp ring.

Claims (1)

[Scope of Claims] 1. A flexible light guide consisting of a coated light guide fiber, in which at least one end of the light guide is provided with a metallic, sleeve-shaped holder, in which the light guide is concentrically arranged. In a flexible light guide for use with a high-power laser beam, which is passed through the substrate and forms a flat end face with the carrier,
The coating 2 of the light guide ends in the holder 3 at a short distance in front of the end face, and the holder 3 is connected to the coating 2.
The stripped ends of the light guide fibers 1 are also tightly fitted and surrounded, the holder 3 having a tapered portion 6 on the side facing said end face, covering the sheath 2 of the light guide over its entire circumference. A light guide characterized in that the metal of the holder 3 has good thermal conductivity. 2. The light guide according to claim 1, wherein the end faces of the light guide fiber 1 and the holder 3 are polished. 3. The light guide according to claim 2, characterized in that the end face of the holder 3 has a mirror lining 4. 4. Claim 1, characterized in that the outer diameter of the holder 3 is considerably larger than the diameter of the light guide fiber 1.
The light guide according to any one of items 3 to 3. 5. Light guide according to one of claims 1 to 4, characterized in that the tapered portion 6 is provided with a clamping ring 7. 6. Claim 1, characterized in that a further metallic holder 5 with a large heat capacity accommodates the optical conductor fiber 1, the holder 3 and the clamp ring 7.
The light guide according to any one of items 5 to 5.