JPH02156208A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To determine the slight of high energy light, and also, to detect abnormality by providing a second optical fiber made of plastic along a first optical fiber for transmitting the high energy light. CONSTITUTION:A second optical fiber 3 in which at least the clad is made of plastic is provided along the lengthwise direction of a first optical fiber 1 for transmitting a high energy light. When a first optical fiber 1 for transmitting the high energy light 5 causes breaking or burning, the high energy light 5 is absorbed in its part and heated, and a second optical fiber 3 in which at least the clad is made of plastic is molted by this heat and the transmission function is deteriorated. Therefore, by always monitoring an emitted light 6 of a second optical fiber 3, abnormality of a first optical fiber 1 can be detected. Also, by transmitting a visible light 6 to a second optical fiber 3, this light can be used as a guide light of the fiber 1 of the high energy light 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to fiber optic cables for transmitting high energy light.

2. Description of the Related Art Conventionally, there are industrial and medical lasers that transmit high-energy light using optical fiber cables, and for example, a YAG laser scalpel (wavelength: 1.06 μm) is known. These optical fiber cables mainly use quartz-based fibers such as quartz glass, and often combine and transmit visible light. In this case, visible light not only functions as a guide light for determining aiming, but also has been used as a means to visually check for breakage or burnout of the optical fiber.

Problems to be Solved by the Invention Regarding the above-mentioned laser, CO, laser (wavelength 10
．． 6 μm) is important as a high-energy light source for both industrial and medical purposes, but it is impossible to transmit using quartz-based optical fibers. Polycrystalline optical fibers based on thallium halide or silver halide are useful for transmitting C02 laser light, but this optical fiber conversely has short wavelengths such as visible light (400 ~
800 nm) is difficult to transmit. Therefore, there was a drawback that it was not possible to combine visible light and use it as a guide to determine the aim of the CO2 laser, or to detect abnormalities in the COx laser.

An object of the present invention is to provide an optical fiber cable that can determine the aim of high-energy light when transmitting high-energy light such as a YAG laser or a Co2 laser, and can also detect abnormalities.

Means for Solving the Problems In order to achieve the above object, the present invention arranges a second optical fiber whose cladding is at least made of plastic along the length of a first optical fiber that transmits high-energy light. The optical fiber cable was installed.

Further, the second optical fiber can also be folded back on the output end side of the first optical fiber.

Function: As described above, the second optical fiber is formed along the length of the first optical fiber.
If the first optical fiber that transmits high-energy light breaks or burns out,
High-energy light is absorbed in that part and generates heat, and at least the second optical fiber whose cladding is made of plastic will melt due to this heat, impairing its transmission function. Therefore, by constantly monitoring the light emitted from the second optical fiber, it is possible to detect an abnormality in the first optical fiber. Furthermore, by transmitting visible light to the second optical fiber, this light can be used as a guide light for a high-energy light fiber.

Example The drawings shown as examples will be explained below.

(Example 1) FIG. 1 shows a cross-sectional view of the output end of an optical fiber cable, where l is a first optical fiber, and a halide polycrystalline optical fiber was used. A protective tube 2 is made of metal such as stainless steel or plastic such as Teflon to protect the first optical fiber l. 3 is the second optical fiber;
It is made of plastic and is glued along the protective tube 2. 4 is the outer covering. Reference numeral 5 indicates a beam, which is an emitted beam of high-energy CO□ laser light, and reference numeral 6 indicates a visible light beam transmitted through the second optical fiber.

In this embodiment, if input is performed with the first optical fiber 1 broken or burned out midway, the abnormal part will overheat, and the second end fiber 3, which has a lower melting point, will be thermally damaged and will not be exposed to visible light. Beam 6 is no longer emitted. Therefore, this visible light beam can be visually recognized at all times during use, and abnormalities in the optical fiber of high-energy light can be detected.

Incidentally, under normal conditions, both the beams 5 and 6 are emitted in a row 94 in close proximity to each other as shown, so that the visible light beam 6 can be utilized as the aiming guide light of the high-energy optical fiber.

As shown on page 71, the first optical fiber 1 is protected by a protective tube 2, which can be made of a metal tube or plastic. The cladding of the second optical fiber 3 via the tubes 2 may be made of plastic, as long as it has a melting point that can be melted by high-energy light.

(Example 2) The second optical fiber 3, in which the output Q was disposed along the first optical fiber l shown in Example 1 up to Mizuki, was not terminated there, but was folded back and returned to the input side. It is something.

If the light emitted from the end of this folded output f= is guided to the photo-electric conversion element, it can be constantly monitored on the hand side.

Therefore, as described in the operation of Example 1, when an abnormality occurs in the first optical fiber, the output of the conversion element changes, and it is also possible to automatically stop inputting high-energy laser light. be. In the above, the second optical fiber does not necessarily have to be visible light.

Effects of the Invention As described above, the present invention detects abnormalities in the first optical fiber by attaching a second optical fiber made of plastic along the first optical fiber that transmits high-energy light. , it can now be used as a guide light for aiming the optical fiber. Therefore,
This has great effects, such as being able to selectively use visible light as the second optical fiber, regardless of the type of high-energy light as in the conventional example.

[Brief explanation of the drawing]

The drawing is a sectional view of a main part of an optical fiber cable showing an embodiment of the present invention. l...First optical fiber 3...Second optical fiber applicant Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] (1) An optical fiber cable characterized in that a second optical fiber having at least a plastic cladding is disposed along the length of a first optical fiber that transmits high-energy light. (2) A second optical fiber having at least a plastic cladding is disposed along the length of the first optical fiber that transmits high-energy light, and the second optical fiber is connected to the first optical fiber. An optical fiber cable characterized by being folded back at the output end side.