JPS62299909A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To sharply improve cooling capacity for optical fiber end faces as compared to the ordinary cooling method directly utilizing the heat transmission of cooling gas for the optical fiber end face parts by utilizing heat transmission based on the face contact of a solid transmitting member for the cooling of the cooling optical fiber end faces. CONSTITUTION:An optical fiber cable system is constituted of energy light rays 1, an optical fiber 2 for leading the energy light rays 1 up to a radiating portion, solid transmitting members 11, 12 arranged in contact with the end faces of the optical fiber 2 and consisting of a transparent material for the energy light rays 1, and a cooling means for cooling the members 11, 12. A cooling function consists of a heat radiating plates arranged on the members 11, 12 and a cooling medium 16 for cooling the heat radiating plates and the energy light rays are infrared rays having >=2mum wavelength. Since the transparent solid transmitting members 11, 12 having the cooling function are arranged in contact with the end faces of the optical fiber 2, the optical fiber end face parts having a large heating value can be effectively cooled.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention is applicable to a light guide path of a laser scalpel or a laser processing machine.

Conventional technology related to optical fiber cables that house optical fibers used In recent years, in laser scalpels and laser processing machines, energy beams such as carbon dioxide lasers and YAG lasers are guided to the target area 1 using optical fiber cables to perform surgery and processing. It is being done.

When guiding high-power energy light through an optical fiber, the following two factors limit the energy transmission ability of the optical fiber.

One is absorption due to impurities inherent in the fiber material, lattice defects, internal scattering, and surface scattering of the optical fiber, which causes a temperature increase over the entire length of the optical fiber. This temperature rise is
In the case of KH2-5 optical fiber as an example, it is about 3 degrees.

The other is absorption by edge reflection and edge polishing layer.
This causes a local temperature rise at the end surface. In this case, the temperature is about 100-odd degrees.

In other words, by effectively cooling the end face, the energy transmission capacity can be increased by 3 bases.

It is thought that this is possible.

A conventional example of the optical fiber end face cooling method is shown in FIG.

As shown in FIG. 3, liquefied gas 4 with a controlled flow rate is ejected from the capillary end 6 toward the end 3 or the entire optical fiber 2 that guides the energy light 1 and is gasified, and the end 3 is cooled. (Refer to Japanese Patent Publication No. 67-133406).

Problems to be solved by the invention First, the diameter of the optical fiber used for energy transmission is φ
This is less than one stroke, which is difficult to achieve by spraying the cooling medium in a concentrated manner onto the end face of the optical fiber.

Second, the optical fiber that transmits infrared light has a weak intensity of 1
There is a limit to how much pressure can be increased by spraying a cooling medium to increase the heat dissipation coefficient.

Thirdly, due to the first and second problems, the increase in the heat dissipation coefficient due to cooling medium spraying is at most one or several times the heat dissipation coefficient in still air.

Means for Solving the Problems The present invention solves the above-mentioned problems of the conventional art. This is an optical fiber cable consisting of a solid transmission member made of a material transparent to energy beams, and a cooling means for cooling the solid transmission member.

Function The optical fiber cooling method of the present invention effectively cools the end face of the optical fiber, which generates a large amount of heat, by arranging a transparent solid transmission member having a cooling function in surface contact with the end face of the optical fiber. It is.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an optical fiber cable in an embodiment of the present invention. As shown in Figure 1.

The infrared optical fiber 2 is made of hot extruded KH2-5 infrared transparent material and is housed in the optical fiber cable 6. The carbon dioxide laser beam 1 passes through a lens 7 made of an infrared-transmissive material Zn5e to an incident end face 3 of an infrared optical fiber.
The light is focused on. Infrared light flow / The laser beam guided through the eyeglass 2 is emitted from the output end face 8, is focused on the processing section 10 by the output lens 9, and is cut,
Welding and heat treatment are performed.

The solid transmitting members 11 and 12 made of the infrared transmitting material Ge are as follows:
It is in surface contact with both end surfaces 3.8 of the infrared optical fiber 2,
Heat generated from the end face is removed by heat conduction. Heat dissipation fins 16 are provided on the outer periphery 14 where the laser beam 13 that passes through the interior of the solid transmission member 11 does not hit, and the fins 16 exchange heat with the cooling gas 16 supplied from the outside. The solid permeable member is cooled by this.

To summarize the above heat flow, the amount of heat generated in the end face polishing layer is transferred to the solid permeable member through solid heat conduction, and the transferred heat is exchanged with cooling gas by the fins on the solid permeable member. By dissipating heat, the end face of the optical fiber can be effectively cooled.

Compared to the conventional method of cooling the optical fiber end face directly by heat transfer of cooling gas, this cooling method utilizes solid heat conduction, so cooling the optical fiber end face is possible. It is thought that the ability is more than two orders of magnitude, and it is extremely effective.

In addition, in this example, as the solid transparent member material, z
nse was used, but Go and Si, which have good thermal conductivity, may also be used.

In addition, as a cooling method for the solid transparent member, a method using radiation fins and cooling gas was used, but as shown in FIG. A circulating method may also be used.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention cools the end face of a cooling optical fiber by using heat conduction through surface contact with a solid transmission member. The cooling capacity for one optical fiber end face is much higher than that of conventional cooling using .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of an optical fiber 71-1> cable in one embodiment of the present invention, FIG. 2 is a cross-sectional side view of a cooling means for a solid transmission member of an optical fiber cable in the same embodiment, and FIG. The figure shows a conventional cooling means for the end face of an optical fiber. DESCRIPTION OF SYMBOLS 1... Laser beam, 2... Optical fiber, 3... Incident end face, 6... Optical fiber cable, 7... Lens, 8... Output end face, 9... Output lens, 11°12...
...Solid transmission member, 15...Fin 116...
... Cooling gas, 17 ... Heat exchanger 118.
·····Cooling water.

Claims (3)

[Claims] (1) An energy beam, an optical fiber that guides the energy beam to the irradiation site, a solid transmission member made of a material transparent to the energy beam and arranged in surface contact with the end surface of the optical fiber, and An optical fiber cable comprising a cooling means for cooling a solid transmission member. (2) The optical fiber cable according to claim 1, wherein the cooling function includes a heat sink provided on the solid transmission member and a cooling medium that cools the heat sink. (3) The optical fiber cable according to claim 2, wherein the energy beam is an infrared beam having a wavelength of 2 μm or more.