JPH047507A - Optical fiber manufacturing equipment and manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus and method for manufacturing an infrared optical fiber used as a light guide in a laser irradiation device such as a laser scalpel.

Conventional technology A Tl called KR8-5 is used as an infrared optical fiber that transmits light in the infrared region including CO2 laser light with low loss.
Optical crystal consisting of Br and TII or JP-A-01-
AgB r- as shown in Publication No. 209407
It is known that optical crystals made of metal halides, such as optical crystals made of AgCl, are molded by a warm extrusion method. The manufacturing apparatus and manufacturing method of this infrared optical fiber will be explained based on FIG. 2. 1 is a punch, 2 is a container 9 3 is a die, and inside this container 2 is the metal halide formed into, for example, a cylindrical shape. The optical crystal 4 made of
It pushes out the infrared optical fiber 6.

Problems to be Solved by the Invention However, with this method, a phenomenon occurs in which the infrared optical fiber 6 extruded from the die 3 is bent or wavy. Especially when the outer diameter of the infrared optical fiber is 0.5 mm. This phenomenon is remarkable when the diameter is as small as t℃.
Forces caused by slight eccentricity or angular deviation of the hole, poor surface roughness, etc. In many cases, it is impossible to judge whether the infrared optical fiber 6 is good or bad without actually pushing it out, and corrections are made through trial and error. This bending and waving ζ002 not only reduces the transmission efficiency of the laser beam, but also widens the emission angle of the laser beam from the optical fiber.

This made it difficult to focus the light, and caused problems such as the laser light leaking or generating heat at bent parts, leading to damage to the infrared optical fiber itself.Furthermore, when assembling the optical cable, Means to solve problems such as difficulty in assembling when the infrared optical fiber has a bend Technical means to solve the above problems This means applying a tension that is greater than the stress and less than the tensile strength.

Here, the yield stress is the stress that causes 0.2% plastic deformation, and the tensile strength is the maximum stress that leads to breakage.

Effect of the above-mentioned means: Due to the applied load, plastic deformation occurs in the fiber, the bending is corrected, and the fiber becomes straight.

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

In Figure 1, 1 is a punch, 2 is a container, 3
is a die, and an optical crystal 4 such as a halide molded into a cylindrical shape is inserted into the container 2. While the optical crystal 4 is heated to 150°C to 250°C with a heating heater 5, the punch 1 is pressed with a hydraulic press. 60 to 100 in the direction of the arrow, etc.
The infrared optical fiber 6 is pressed out with a pressure of 1 kg/mm. A weight 8 having a clamping part 7 is added to the tip of the extruded infrared optical fiber 6 as a tension applying means. A load greater than the yield stress and less than the tensile strength of the infrared optical fiber 6 is used.

The results of extruding the infrared optical fiber 6 using the manufacturing method of the present invention will be explained. The composition ratio of AgBr and AgC1 is A
gBr = 57% by weight AgC 143% by weight optical crystal is extruded to a diameter of 0.3 mm.The yield stress of the infrared optical fiber at this time is approximately 3.5 kg/Cm2, and the tensile strength is approximately 6.4 kg/Cm2. It is. Therefore, a tension of 4.2 kg/cm'' within this range is applied to the infrared optical fiber, which is approximately 300 g when converted to an optical fiber with a wire diameter of 0°3 mm.
This corresponds to the load, so set weight 8 to this value.
The O2 laser beam was focused through a condensing lens with a focal length of 1.5 inches, and the transmission efficiency and laser emission angle from the optical fiber were measured. The results are shown in Table 1.

Table 1 As shown in Table 1, the infrared optical fiber of this example was extruded under a load greater than the yield stress of the material and less than the tensile strength.
Significantly better results can be obtained in both output angles than with an unloaded infrared optical fiber.

Since the infrared optical fiber obtained in this example is in a very straight state, it is easy to assemble it when assembling the light guide path. The effect is the same.

Also, regarding various types of fibers, it has been said that good fibers can be obtained if the applied load is greater than the yield stress and less than the tensile strength. .

Effects of the Invention According to the present invention, an extruded infrared optical fiber (extruded straight without bending or waving), which has high laser beam transmission efficiency and a stable infrared optical fiber with a small laser emission angle, can be obtained. It will be done.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing the configuration of an embodiment of an infrared optical fiber manufacturing apparatus according to the present invention. FIG. 2 is a configuration diagram of a conventional infrared optical fiber manufacturing apparatus.

Claims (1)

[Claims] (1) An optical fiber consisting of a container that heats and stores an optical crystal, a punch that pressurizes the optical crystal inside the container, and a die installed inside the container that extrudes the pressurized optical crystal into a linear fiber. An optical fiber manufacturing apparatus comprising a forming means and an optical fiber tension applying means for applying a stress equal to or higher than the yield stress of the optical fiber and equal to or lower than the tensile strength of the optical fiber to be extruded. (2) In an optical fiber manufacturing method in which an optical fiber is formed by extruding the optical crystal from a die while heating the optical crystal, the extruded optical fiber has a yield stress higher than the yield stress and lower than the tensile strength of the optical fiber. A method of manufacturing an optical fiber characterized by adding stress.