JPH1062658A - Optical fiber adjusting method for invisible laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning method in which an invisible laser beam is directly used without using the visible laser such as He-Ne laser. SOLUTION: A dummy member is arranged in the incident end position of an optical fiber ($3), a laser beam passed through an incident optical system is irradiated on the dummy member so as to be damaged (S5), the image of the surface of the damaged dummy member is picked up and displayed on an image display unit, and the position displayed on the image display unit is stored (S6), an optical fiber is arranged after the dummy member has been removed (S7), the relative position of the incident optical system and the optical fiber incident end is adjusted so that the optical fiber incident end position in the image display unit is superposed on the damaged position of the surface of the dummy member (S10), position adjustment is carried out so that the optical fiber incident end is brought into line with the stored dummy damaged position for introducing the laser beam to the optical fiber, and the energy of light outgoing from the optical fiber output end is measured (S11), and the spatial position of the optical fiber incident end is finely adjusted so that the energy takes the maximum value (S14).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting an optical fiber for an invisible laser, and more particularly, to an invisible laser such as an iodine laser or a YAG laser for directly positioning an incident end of an optical fiber by directly utilizing an optical path thereof. The present invention relates to an optical fiber adjusting method for a laser.

[0002]

2. Description of the Related Art An iodine laser emits a laser beam having a wavelength of 1.315 μm, and a YAG laser emits a laser beam having a wavelength of 1.064 μm.
Of laser light. These laser light wavelengths are in a region where the optical transmittance of the optical fiber is large, and it is possible to carry or distribute laser light energy to a remote place using the optical fiber. The large output of these laser beams and the large remote transmission capability are extremely advantageous for industrial use. In order to take advantage of the characteristics of laser distribution and high output performance, it is important to accurately collect light at the input end of the optical fiber so as not to damage the input end of the optical fiber which is easily damaged.

[0003] However, since the wavelength of a laser beam such as an iodine laser or a YAG laser is in a near-infrared region and is outside a visible region of a human, a human cannot directly see the optical path. Therefore, the generation of these invisible lasers
The optical axis adjustment in the transmission device cannot be done visually,
In general, a He-Ne laser device is separately provided in the optical axis of the laser, and the laser beam is emitted based on the optical path of a red visible laser beam having a wavelength of 632.8 nm.

FIG. 9 is a block diagram showing an example of a conventional optical fiber adjusting method for an invisible laser. As shown in FIG. 9, a small He-Ne laser device is arranged on the rearward extension of the optical axis of an invisible laser generator such as an iodine laser, and 632.8 nm of He from the back side of the resonant reflector of the invisible laser generator. Irradiate the Ne laser so that the visible light laser beam follows the optical axis of the invisible laser. The coordinator adjusts the position of the red laser beam, which is visible to the naked eye, through the input optical system so that the red spot formed on the optical fiber input end surface matches the core of the optical fiber, or adjusts the red laser beam from the optical fiber output end. Was adjusted so that the light was emitted efficiently and the brightness was maximized.

[0005]

However, since the wavelength of the invisible laser and the wavelength of the He-Ne laser are different from each other, even if the two laser beams pass through the same optical system, the focus positions are slightly different due to chromatic aberration. . Therefore, the adjustment of the invisible laser relying on the He-Ne laser is not a strict adjustment. There is also a method of correcting the position by calculating an error caused by the difference in wavelength based on the focal position of the He-Ne laser. However, in order to avoid complexity and inaccuracy, the position is directly adjusted with a laser beam to be used. It was requested. Therefore,
The problem to be solved by the present invention is to provide a positioning method directly using an invisible laser beam to be used.

[0006]

According to the present invention, there is provided a laser apparatus comprising a laser generator, an incident optical system, and an optical fiber, wherein a laser beam is accurately incident on an optical fiber incident end. An optical fiber adjusting method for a laser includes a method of arranging a dummy material at an optical fiber incident end position, irradiating the dummy material with laser light that has passed through an incident optical system, damaging the dummy material, imaging the surface of the damaged dummy material, and displaying the image on an image display device. The optical fiber and the optical fiber are attached so that the dummy fiber is removed, the optical fiber is attached, and the optical fiber incident end position in the image display device and the previously damaged position of the dummy material surface are overlapped. Is characterized by adjusting the relative position of. Further, the optical fiber input end is placed at the position where the dummy material is damaged, the laser light is guided to the optical fiber, the energy of the light emitted from the optical fiber output end is measured, and the optical fiber input end is set so that the energy takes a maximum value. Is preferably adjusted.

Further, in the optical fiber adjusting method for an invisible laser according to the present invention, a mechanism for restricting the laser light before irradiating the dummy material with the laser light is provided in the incident optical system, and the laser generator is controlled by the restricting mechanism. It is preferable to control a portion of the energy of the emitted laser light that is irradiated on the dummy material so as to cause appropriate damage to the dummy material surface. Furthermore, before measuring the energy of the light emitted from the output end of the optical fiber, a laser light restricting mechanism is interposed in the incident optical system, and the light within the energy of the laser light emitted from the laser generator by the restricting mechanism is measured. It is preferable to control a portion irradiated to the fiber entrance end so as not to damage the optical fiber entrance end.

In the optical fiber adjusting method for an invisible laser according to the present invention, the laser light restricting mechanism may divide the laser light temporally. Further, the above-described laser beam that is temporally divided may be configured by inserting a rotating disk having an opening into the optical path of the laser beam. Further, the laser beam restricting mechanism may be such that a partially transmitting mirror and a transmissive member having an optical path length equivalent to that of the partially transmitting mirror are arranged in the optical path of the laser light at mutually complementary angles. Further, in the optical fiber adjusting method for an invisible laser according to the present invention, in the step of imaging the optical fiber incident end, the optical fiber output end may be irradiated. In addition, the method for adjusting an optical fiber for an invisible laser according to the present invention displays the surface of the dummy material on the image display device, and affixes a sheet indicating the invisible laser light condensing position to the damaged position. The light position can be stored.

In the method for adjusting an optical fiber for an invisible laser according to the present invention, the dummy fiber is placed at the position where the optical fiber input end is located by removing or shifting the optical fiber input end, and then passing through the actual input optical system. The surface of the dummy material is damaged by irradiating the dummy material with the laser light, and the surface of the damaged dummy material is imaged and displayed and stored on the image display device.
The damage position on the surface of the dummy material indicates the actual condensing position of the invisible laser light. If the previously stored damage position on the surface of the dummy material is displayed on the display screen, the deviation between the position and the optical fiber incident end position displayed on the image display device can be easily and clearly understood. The relative position between the incident optical system and the dummy material is mechanically adjusted so as to match. When the damaged position of the dummy material and the position of the core position of the optical fiber incident end are thus matched, the position of the optical fiber incident end coincides with the optical axis position of the laser beam.

Further, the optical fiber input end is returned to the original position from which the dummy material has been removed, the laser light is guided to the optical fiber via the input optical system whose position has been adjusted, and the laser light emitted from the output end of the optical fiber is output. The energy is measured with a power meter or the like, and the spatial position of the optical fiber incident end is finely adjusted so that the light energy has a maximum value. In this way, it is possible to adjust the laser light so as to be accurately incident on the optical fiber incident end, even though the laser light is invisible. In addition, if the dummy material is irradiated with laser light having an intensity capable of laser processing such as welding or cutting, the degree of damage may be too large to be used for position adjustment, but the laser light is irradiated on the dummy material. In the optical fiber adjusting method for an invisible laser, in which a mechanism for restricting laser light is interposed in the incident optical system, the intensity of the laser light emitted from the laser generator is controlled by the restricting mechanism before the surface of the dummy material is controlled. Can be limited so that the surface is appropriately damaged.

Further, if the laser beam having the intensity required for use as a laser device in the state where the adjustment is not yet completed is attempted to be incident from the optical fiber input end, the laser beam hits outside the core region of the optical fiber and the sheath portion of the optical fiber. Etc. may be damaged due to overheating and severely damaged. However, according to the optical fiber adjustment method in which the laser light restricting mechanism is interposed in the incident optical system during the measurement, the restricting mechanism controls the energy of the laser beam applied to the optical fiber incident end and damages the optical fiber incident end. Not be given.

A simple mechanism for dividing the laser light in time, particularly when a rotary disk having an opening is inserted into the optical path of the laser light, is adopted as the laser light limiting mechanism. Thus, it is possible to limit the target laser light energy, and depending on the selection, there may be a case where the laser device can be used as it is by fixing the opening along the optical axis even after the adjustment. Also,
When the laser beam restricting mechanism adopts a partially transmitting mirror and a transmissive body having an optical path length equivalent to that of the partially transmitting mirror arranged in the optical path of the laser beam at a complementary angle to each other, there is no movable part. Accurate adjustment can be easily performed.

Further, when the optical fiber output end is illuminated by an illumination device when the optical fiber incident end is imaged, a clear core image is obtained in which the core portion at the optical fiber incident end is clearly brighter and brighter than the other portions. can do. Also, by displaying the surface of the dummy material on the image display device and attaching a sheet showing an appropriate mark to the damaged position to store the invisible laser irradiation position on the display screen, a special image processing device or Even without a processing program, the position can be easily and inexpensively stored.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical fiber adjusting method for an invisible laser according to the present invention will be described in detail with reference to the drawings.
FIGS. 1 to 4 are conceptual diagrams illustrating the procedure of an embodiment of the optical fiber adjusting method for an invisible laser according to the present invention. The method for adjusting an optical fiber for an invisible laser according to the present invention can be used for any invisible laser having an energy higher than the damage of the dummy material, but the present embodiment is directed to an iodine laser.

FIG. 1 is a flowchart showing the procedure of the optical fiber adjusting method of the present invention. FIG. 2 is a block diagram showing a first stage in the optical fiber adjusting method of the present invention, FIG. 3 is a block diagram showing a second stage, and FIG. 4 is a block diagram showing a third stage. As described in FIG. 1, when the adjustment of the optical fiber is started (S1), first, the imaging device is set (S1).
2) The dummy material 27 is set at the optical fiber incident end position (S3). It is preferable to set the dummy material accurately so that the surface of the dummy material comes to the end face position of the optical fiber incident end 21.

Then, the laser device 1 is operated to irradiate the laser beam to the dummy material through the incident optical system 3 to damage the surface (S5). The irradiation position of the invisible laser can be visualized by damaging the surface of the dummy material. If the laser beam is too strong and the dummy material is damaged or damaged so that the irradiation position cannot be determined accurately, a mechanism to cut the laser output is provided in the laser beam path to suppress and adjust the laser beam (S4). Next, the laser device 1 is stopped, and the surface of the dummy material damaged by the laser is imaged to monitor 4.
3 is displayed. The transparent sheet is adhered to the monitor surface such that both the center position of the transparent sheet 45 in the target view and the center of the damaged position of the dummy material coincide (S6).

FIG. 2 is a view showing a setting state of the apparatus in the above process. The optical fiber device 2 of the laser device is removed, and the dummy material 27 is placed at that position. Dummy material 2
Reference numeral 7 denotes, for example, an aluminum plate having an appropriate thickness attached to a support member. The position of the surface of the aluminum plate is set to be the same as the position of the surface of the optical fiber incident end 21. Since the iodine laser beam emitted from the iodine laser oscillator 11 has a kw-class output that can cut an iron plate, if the iodine laser beam is irradiated on the dummy material 27 as it is, the damage is too large and the laser irradiation position cannot be correctly known. Therefore, by inserting the energy limiting device 13 into the optical path, suppressing the energy of the laser beam to an appropriate value, and irradiating the laser beam to the surface of the dummy material 27, an appropriate size for confirming the laser irradiation position is obtained. Damage is given to the dummy material 27. Since the shutter allows the iodine laser to pass through for a very short time, the shutter can be used as the energy limiting device 13 for appropriately damaging the dummy material 27.

The imaging device 4 includes a CCD camera 41 and a monitor 4
The CCD camera 41 captures an image of the surface of the dummy material 27 via the reflecting mirror 31 and the lens 33, and the monitor 43
To display the image. The operator places the transparent sheet 45 on which the target figure is clearly displayed so that the center of the target is aligned with the center of the damage position on the surface of the dummy material and the invisible laser irradiation position displayed on the monitor 43. Affixed to the damaged position on the surface of the dummy material indicating Usually, since the cross-sectional shape of the fiber is circular, it is convenient to use a transparent acrylic sheet with a circular shape. The position and shape of the dummy material surface damage can be easily confirmed by irradiating a visible light such as an electric light on the dummy material surface. In this way, the damage position on the surface of the dummy material 27 which indicates the invisible laser focus position at first can be stored in the image plane of the monitor 43.

Returning to FIG. 1, the optical fiber incident end is returned to the original position except for the dummy material 27 (S7). An illuminating device is set at the optical fiber emitting end and illuminated (S8), and the center position of the target figure of the transparent sheet 45 affixed to the monitor surface is compared with the core position of the optical fiber (S9) so that the two coincide. Then, the relative position between the input optical system and the optical fiber input end is adjusted (S10).

FIG. 3 is a drawing showing the setting state of the apparatus in the above process. A laser generator 1 having an iodine laser oscillator 11, an optical fiber device 2 having an input end 21 and an output end 23 coupled by an optical fiber 25, and a reflecting mirror 3
An imaging device 4 and an illuminator 5 are set in a laser device including an optical fiber 1 and a lens 33 and an incident optical system 3 for guiding a laser emitted from the laser generator 1 to the optical fiber incident end 21. The illuminator 5 is a light emitting device that generates visible light such as an electric lamp. The reflection mirror 31 is provided with a coating that reflects laser light and transmits visible light from the illuminator 5. The surface of the optical fiber input end 21 is imaged by the CCD camera 41 and displayed on the monitor 43. The operator compares the position of the core center of the target diagram of the transparent sheet 45 attached to the display surface with the displayed core center position of the optical fiber,
The adjustment is made by moving the incident optical system 3 so that there is no deviation between the two.

Returning to FIG. 1 again, when the damage position stored on the screen coincides with the displayed position of the core image (S9), the laser light energy output from the optical fiber emission end 23 is output. Is set (S11), and a mechanism for cutting the laser output is provided in the laser beam path so that the laser beam can be suppressed and adjusted (S12). The energy of the laser light transmitted through the system 3 and the optical fiber device 2 is measured. The value measured by the power meter is observed, and the center of the core of the optical fiber input end 21 and the focal position of the laser are finely adjusted (S14) so that the laser light energy has a maximum value (S13).

FIG. 4 is a view showing a setting state of the apparatus at the time of the fine adjustment. The dummy material 27 placed at the position of the optical fiber incident end 21 of the laser device is removed, and the optical fiber incident end 21 is set again. Careful adjustment is performed so that the core of the optical fiber input end 21 is located at the damaged position of the dummy material 27. A laser light measuring device 6 including a power meter 61 and an indicator 63 is set at the optical fiber emitting end 23. The iodine laser emitted from the optical fiber emission end 23 is absorbed by the power meter 61, and the absorbed heat is displayed on the indicator 63.

As a result of the above fine adjustment, the iodine laser oscillator 1
The iodine laser emitted from the optical fiber 1
The center of the core is illuminated or in the immediate vicinity of the core, but due to problems with position repeatability and the lack of optimization of the axial position, more precise adjustments are required. is necessary. Since the iodine laser emitted from the iodine laser oscillator 11 is strong enough to cut an iron plate,
If there is light that directly irradiates the protective layer of the optical fiber or light that has a large incident angle, there is a concern that the optical fiber protective layer made of resin may be damaged by the direct irradiation light or light leaking from the clad.

Therefore, the energy limiting device 15 is inserted into the optical path to suppress the energy of the laser beam to an appropriate value that does not damage the protective layer, and then irradiate the optical fiber incident end 21 with the laser. The laser light passes through the optical fiber 25, exits from the exit end 23, is captured by the power meter 61, and the energy is displayed on the indicator 63. The energy limiting device 15 used in this step may be the same as the energy limiting device 13 used in the previous step, but is different when the degree of energy suppression required in each step is different. The device may be replaced. Alternatively, both energy suppression devices may be switched and used together.

The axial positioning of the input end of the optical fiber is performed by: 1) performing the above-described fiber position adjustment in a plurality of axial directions to find an axial position where the transmittance is maximized; In addition, the output from the fiber output end is measured using a meter, and the position of the fiber is finely adjusted so that the output is maximized. 3) The position of the fiber is adjusted at a certain axial position. There is a method of searching for a local maximum value by finely adjusting each direction including the direction.

In order to adjust the position of the optical fiber input end 21, an optical fiber input end fine adjustment device 29 for driving the optical fiber input end 21 in three axes is provided. The operator changes the position of the optical fiber input end 21 while looking at the indication of the indicator 63 of the power meter, and searches for the position where the maximum value is obtained. 3
If each of the axes is sequentially adjusted so as to show the maximum value for each axis, the position becomes the position of the maximum energy.

In the above embodiment, the energy limiting device 1
For example, shutters that transmit the iodine laser for an extremely short time are used for 3 and 15, but the energy can be limited by dividing the laser light in time by using a chopper as shown in FIG. . The chopper is configured to rotate a rotating disk 72 having a hole such as a slit 71 or a circle around a shaft 73.
The power of the iodine laser light can be cut by inserting the laser light into the optical axis of the laser light emitted from the laser oscillator 11. One or more openings 71 are provided, and the output level can be changed according to the ratio of the opening to one rotation of the disk 72.

Another method for cutting the output light of the iodine laser is to use a partial mirror as shown in FIG. The mirror 74 is inserted at a predetermined angle に 対 し て such as 45 degrees with respect to the optical axis of the laser beam emitted from the laser oscillator 11. The laser light reflected according to the reflectance of the mirror 74 enters the power dump 75 and is removed, and the rest is irradiated to the dummy material or the optical fiber incident end. If the reflectivity of the mirror 74 is, for example, 99.5%, the transmitted light is 0.1%.
5%. By appropriately selecting the reflectivity of the mirror 74 in this manner, it is possible to appropriately damage the dummy material and eliminate damage to the fiber.

However, when only one mirror 74 is inserted, the optical axis moves in one direction due to the thickness of the mirror 74, and the optical path is different from that when the mirror 74 is removed. Therefore, a mirror or a simple glass plate 76 of the same glass and the same thickness is inserted into the optical path and arranged so as to form a supplementary angle (180-Θ) with the mirror 74 so that the optical path of the laser light coincides with the original optical axis. To do. Thus, the irradiation position is not changed even if the energy limiting devices 13 and 15 are attached and detached. Note that the angle Θ may be selected so that the laser beam reflected by the mirror 74 is out of the optical axis, so that the angle Θ is not limited to 45 degrees and may be an appropriate value. When only one mirror 74 is inserted, the optical axis moves slightly in parallel. However, if only the parallel movement is performed, the position of the laser beam does not basically change, so that the mirror or the glass plate 76 can be omitted.

In this embodiment, in order to record the damaged position of the dummy material indicating the irradiation position of the invisible laser on the monitor, a method of sticking a transparent sheet with a circle on the monitor screen is used. The image acquired by the CCD camera may be stored in the image memory and displayed on the monitor again if necessary. At this time, the damage image of the dummy material and the core image of the optical fiber can be superimposed and displayed. Further, the position and shape of the dummy material damage may be displayed on a monitor, traced with a pointer, and the trajectory thereof may be stored and displayed when necessary. As described above, first, the dummy material is irradiated with the laser to display the damage position on the monitor display surface, and then the optical fiber incident end position is imaged and lighted so as to match the laser damage position while being superimposed and displayed on the monitor. Adjusting the fiber incident end position has the effect of facilitating the adjustment because the image to be adjusted can always be observed.

It should be noted that, of the laser beam emitted from the laser device 1, a component which is not correctly incident on the optical fiber 2 from the beginning is adversely affected by, for example, overheating the fiber incident end 21, so that it is better to remove the component in advance. FIG. 7 and FIG. 8 are views for explaining a method for removing such a laser beam component having an adverse effect. An aperture 81 shown in FIG. 7 is provided between the laser device 11 and the reflecting mirror 31, and the laser device 11
This removes components of the laser beam from the laser beam that have spread more than necessary and do not clearly enter the fiber. An appropriate circular hole 82 is formed in the aperture 81, and by blocking a component off the optical axis of the laser beam 83 having a certain spread emitted from the laser device 11, only a paraxial component having good laser quality is provided. Is transmitted. Further, instead of or together with the aperture 81, a pinhole plate as shown in FIG. 8 can be used. That is, the laser light from the laser device 11 is once focused using the lens systems 84 and 85, and the small holes 8 are located at the focused position.
The quality of the laser beam is improved by installing a pinhole plate 87 having 6 to remove unnecessary components that do not focus properly.

[0032]

As described above, the method for adjusting the optical fiber for an invisible laser according to the present invention, when constituting an invisible laser device such as an iodine laser or a YAG laser, has a wavelength different from that of the invisible laser device. Since the laser irradiation position and the optical fiber incident end position can be directly adjusted without using a He-Ne laser or the like that causes a difference in the above, an accurate optical fiber incident position adjusting device for an invisible laser is manufactured. be able to.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure in an embodiment of an optical fiber adjusting method for an invisible laser according to the present invention.

FIG. 2 is a block diagram showing a first stage in the optical fiber adjusting method of the present invention.

FIG. 3 is a block diagram showing a second stage in the optical fiber adjusting method of the present invention.

FIG. 4 is a block diagram showing a third stage in the optical fiber adjusting method of the present invention.

FIG. 5 is a conceptual diagram showing an example of an energy limiting device used in an embodiment of the present invention.

FIG. 6 is a conceptual diagram showing another example of the energy limiting device used in the embodiment of the present invention.

FIG. 7 is a diagram illustrating a method for removing unnecessary laser light components in a laser device to which the present invention is applied.

FIG. 8 is a view for explaining another method for removing unnecessary components in a laser device to which the present invention is applied.

FIG. 9 is a block diagram illustrating a configuration example of a conventional optical fiber adjusting method for an invisible laser.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser generator 11 iodine laser oscillator 13 energy limiting device 2 optical fiber device 21 incident end 23 emission end 25 optical fiber 27 dummy material 3 incident optical system 31 reflecting mirror 33 lens 4 imaging device 41 CCD camera 43 monitor 45 transparent sheet 5 lighting Instrument 6 Laser light measuring device 61 Power meter 63 Indicator 71 Slit 72 Rotating disk 73 Rotating axis 74 Mirror 75 Power dump 76 Glass plate 81 Aperture 82 Circular hole 83 Laser beam 84, 85 Lens 86 Small hole 87 Pinhole plate

Claims (9)

[Claims] 1. An adjusting method for accurately inputting laser light to an optical fiber input end in a laser device comprising a laser generator, an input optical system, and an optical fiber, wherein a dummy material is provided at the position of the optical fiber input end. The dummy material is damaged by irradiating the dummy material with laser light that has been placed and passed through the optical system.The position where the damaged dummy material surface is imaged and displayed on the image display device is stored. The optical fiber entrance end is imaged and displayed on the image display device, and the incident optical system and the optical fiber entrance end are overlapped so that the position of the optical fiber entrance end in the image display device and the damage position on the surface of the dummy material overlap. Adjusting the relative position of the optical fiber. 2. The optical fiber adjusting method for an invisible laser according to claim 1, wherein a mechanism for restricting the laser light before irradiating the dummy light with the laser light is interposed in the incident optical system. A method for adjusting an optical fiber for an invisible laser, wherein a part of the energy of the laser light emitted from the laser generator, which is emitted to the dummy material, is controlled by a mechanism to cause appropriate damage. 3. The method for adjusting an optical fiber for an invisible laser according to claim 1, wherein the optical fiber input end is arranged at the damaged position of the dummy material, the laser light is guided to the optical fiber, and the light is emitted from the optical fiber output end. Measuring the energy of the optical fiber and finely adjusting the spatial position of the optical fiber incident end so that the energy takes a maximum value. 4. An optical fiber adjusting method for an invisible laser according to claim 3, wherein a mechanism for limiting the laser light before measuring the energy of light emitted from the output end of the optical fiber is provided in the incident optical system. And controlling a portion of the energy of the laser light emitted from the laser generator to be irradiated on the optical fiber incident end by the mechanism so as not to damage the optical fiber incident end. Optical fiber adjustment method for invisible laser. 5. The optical fiber adjusting method for an invisible laser according to claim 2, wherein the laser light restricting mechanism divides the laser light temporally. Fiber adjustment method. 6. An optical fiber adjusting method for an invisible laser according to claim 5, wherein the laser beam is divided in time by inserting a rotary disk having an opening into an optical path of the laser beam. A method for adjusting an optical fiber for an invisible laser, the method comprising: 7. The optical fiber adjusting method for an invisible laser according to claim 2, wherein the laser light restricting mechanism includes a partially transmitting mirror, and the partially transmitting mirror is arranged at an angle to an optical path. Characterized in that, in addition to the partial transmission mirror, a transmissive body having an optical path length substantially equal to that of the partial transmission mirror is arranged in the optical path of the laser beam at a complementary angle to each other. Optical fiber adjustment method for laser. 8. The optical fiber adjusting method for an invisible laser according to claim 1, wherein in the step of imaging the optical fiber incident end, an output end of the optical fiber is irradiated. Fiber adjustment method. 9. The method for adjusting an optical fiber for an invisible laser according to claim 1, wherein a surface of the dummy material is displayed on the image display device, and a sheet indicating an invisible laser irradiation position is provided on the image display device. A method for adjusting an invisible laser optical fiber, comprising storing an invisible laser irradiation position in an image display device by attaching the invisible laser irradiation position to a surface damage position.