JPS58188174A - Laser device - Google Patents

Abstract

PURPOSE:To obtain a multipurpose laser device by a method wherein a laser light is led to an object by alternatively using a mirror wave guide and a fiber wave guide, and a light source is so controlled that the power at an output end becomes the same by either wave guide. CONSTITUTION:From the medium situation between the dimension, shape, and laser light source of the object, an operator decides the selection of the wave guide of a mirror 3 or that of a fiber 4, and then specifies a necessary operating output PW to a circuit 16 by operating a mirror 5. The kind of wave guides is discriminated 15, then the laser output P0 corresponding to the wave guide is calculated 17 from the specified PW, and thus the P0 is outputted by controlling 18 the CO2 gas laser operating light source 1. The P0 attenuates during transmission and becomes a desired PW at an exit. By this constitution, a desired output can be easily obtained, and the operation can be advanced safely, securely, and rapidly. The deterioration with age of the conduction efficiency of the wave guide is small, and the laser light source is automatically controlled even when the wave guides are changed over, accordingly a stable operating output PW can be successively obtained. The light source 2 is used for a guiding light and emits He-Ne laser.

Description

Detailed Description of the Invention The present invention selectively uses a mirror waveguide or a fiber waveguide to guide laser light to a target object, and when either waveguide is used, the output end This applies to a laser device in which the laser power at both ends is the same.

Carbon dioxide lasers have many oscillation lines in the far infrared region,
In particular, the l006- oscillation line produces the maximum output. It has a high conversion efficiency from electrical energy to optical energy, and can obtain high output even with continuous oscillation. The carbon dioxide laser is
It is used in many fields as a high-efficiency, high-output laser. For example, it has a wide range of uses as laser processing equipment and laser treatment equipment.

Carbon dioxide laser light is invisible to the human eye. In order to accurately guide this light beam to the target object, visible light is used as a guide light. As a guide light source, for example, He-Ne
A laser is used.

The working light and guide light of the carbon dioxide laser are guided on the same optical axis in an overlapping manner.

Conventionally, a mirror waveguide has been used to guide the working light of a carbon dioxide laser.

FIG. 2 is a schematic diagram of a mirror waveguide according to a conventional example.

A working light source 21 such as a carbon dioxide gas laser that generates high output infrared light and a guide light source 22 such as a He-Ne laser that generates visible light are used.

Mirrors 23,24 superimpose the visible guide light from the guide light source 22 onto the infrared working light.

The working light is reflected by a plurality of mirrors 25, 26, 27, . . . and travels through the mirror waveguide 28.

The mirror waveguide 28 is a combination of a plurality of pipes and joints that connect the pipes, and the joints are provided with mirrors.

The pipe is only allowed to move within certain limits using the joints as fulcrums. Since the pipe axis must make the same angle as the mirror normal, the only relative movement of the pipe at the joint is rotation about the mirror normal.

The mirror waveguide thus has a poor degree of freedom of movement and is not flexible.

It is difficult to guide working light to an object at an arbitrary position.

In order to increase the degree of freedom, the number of pipes and joints must be increased.

Because it combines twisted pipes and joints, mirror waveguides require a large amount of space to allow free movement.

Mirror waveguides, however, have the advantage of less attenuation because the working light propagates through the air.

Currently, in order to guide the working light of the carbon dioxide Gannulas laser,
Mostly mirror waveguides are used.

On the other hand, in pursuit of waveguide flexibility, far-infrared fiber waveguides are being developed. However, there is still no optical fiber with sufficiently low attenuation for 10.6 μm light and other far-infrared light.

In this way, a fiber-based waveguide uses
It is not as good as a mirror waveguide in terms of transmittance.

FIG. 3 is a schematic diagram of the fiber waveguide.

The light from the working light source 31 and the guide light source 32 follows the working light coupling lens 33 and the guiding light coupling lens 34, and is made to enter the working light fiber 35 and the guide light fiber 36.

The working light and the guide light travel through the fiber waveguide 37 and are guided to arbitrary locations. This is because the fibers 35 and 36 can be bent freely.

After exiting the fiber, mirrors 38,39 match the guiding light to the working light. Such a fiber waveguide is
Since the attenuation of infrared light in the optical fiber is still large, there is a drawback that the transmission efficiency is low. Another drawback is that the fiber has low durability and cannot transmit large amounts of energy.

The third drawback is that the laser beam cannot be sharply focused in the working area. This is because the coherency of the laser is lost due to narrow transmission, and the laser cannot be narrowed down sharply even if a lens is used. As described above, although fiber waveguides have serious drawbacks, they have the advantage of being highly flexible, having good operability and workability, and that the waveguide can be made compact. If the target is small and high output power is not required, fiber waveguides can also be used.

For this reason, it is used in a small number of laser scalpel devices.

Mirror waveguides and fiber waveguides are
I have knowledge. It is difficult to say whether one or the other is particularly prominent. This is how the inventor concludes.

Conventionally, only laser devices employing one of the waveguides have been installed. There is no one that has both waveguides and allows them to be used alternatively.

The inventor thought that it would be convenient if there was something that included both a mirror waveguide and a fiber waveguide.

There is one problem.

This means that the two waveguides have different transmission efficiencies η. The transmission efficiency of a mirror waveguide is about 0.9, and the transmission efficiency of a fiber waveguide is about 0.5.

Although the transmission efficiency varies depending on the length of the waveguide, it is generally within the above range.

If the laser output is the same, the energy lost while being transmitted through the waveguide is different, so the groove waveguide output 1.
The energy is different. In other words, the working power when irradiating the "I" symbol is different.

What the user actually wants is 1jfi 8' to the target object.
This means that you can specify the laser power when adding +. Even if the laser output power PO is known, the working power Pw cannot be immediately known because of the loss caused by the waveguide.

The working power Pw is the laser output power PO multiplied by the transmission efficiency.

Pw = ηPO For example, if you want the working power at the tip of the waveguide to be 50W, the laser output power is 56W for the mirror waveguide.
This means that 100W is required for the W1 fiber waveguide.

Even though two waveguides are provided, it is inconvenient if the working power PW changes when switching between the two.

Using a power meter, the power of the beam at the tip of the waveguide must be repeatedly measured. Birch memata is troublesome.

The present invention provides a laser device that solves these difficulties.
”, the purpose is to achieve.

The laser device of the present invention includes a mirror waveguide and a fiber waveguide to be used alternatively, and the transmission coefficient η of each waveguide.
m, ηf, and desired waveguide tip output (working power) P
From w, the required laser output/<war PO is calculated, and the laser is tilted to the side so as to produce this output power PO.

When a mirror waveguide is used, if the output J at the tip of the waveguide is Pm, then Pm = ηm P for the laser output/< power PO.

I can get a no. Therefore, the laser output power PO is
If the desired working power Pw is determined so that PwPo=-ηm, then pm=Pw.

Hereinafter, the F-1 embodiment will be explained in detail with reference to the drawings.

FIG. 1 is a schematic 1s diagram of a laser device according to an embodiment of the present invention.

Work light source 1 is a high-output infrared laser such as a carbon dioxide laser.
shall be. Visible light lasers such as He-No)・
Used as light source 2.

In order to guide working light and guide light, a mirror waveguide 3 and a fiber waveguide 4 are provided, and a switching mirror 5 is provided to selectively use both waveguides.

Mirror waveguides 3 are well known.

An appropriate number of pipes, joints that rotatably connect the pipes, and mirrors Ml, M2, M3, etc. provided at the joints.
It consists of...etc.

When using mirror 4 wave path 3, the guide light is mirror 6,
A selectively transmitting mirror 7 matches the working light.

The working light and the guide light whose round axes coincide are incident on the mirror waveguide 3.

When the switching viewing mirror 5 is moved to the position indicated by the dashed line, the light beam is switched to the fiber waveguide 4.

The working light is condensed by the working light coupling lens 9, and the working light is
into the optical fiber 11.

The guide light is reflected by the mirror 8, passes through the guide coupling lens 10, and enters the guide light fiber 12.

Since there is still no optical fiber that can transmit both working light and guide light with little attenuation, separate fibers are used.

After passing through the guide light fiber 12, the guide light is sent to the working light by mirrors 13 and 14.

The waveguide identification unit 15 is a mechanism for identifying which waveguide, a mirror waveguide or a fiber waveguide, is being used. Since the switching mirror 5 is switched by being translated or rotated in this way, the waveguide can be identified by detecting the orientation of the switching mirror 5.

The waveguide tip output instruction section 16 instructs the laser power Pw required for the work at the waveguide output. This is specified by the worker.

In order to obtain the working power Pw, the laser output power - P
The arithmetic processing unit 17 calculates in S1 how much o should be.

The calculation formula for determining the laser output power ~Po from the working power Pw differs depending on the type of waveguide. Which waveguide is selected can be determined by the identification signal from the waveguide identification section 15.

The simplest method is to use a simple proportional formula. That is, (1) If it is a mirror waveguide, lol Po = - (1) th is required. η□ is the transmission efficiency of the mirror waveguide.

(2) In the case of a fiber waveguide, w Po = −(2) ηf is obtained. ηf is the transmission efficiency of the fiber waveguide.

Generally speaking, the equations (1) and (2) may include a slight correction term, but in most cases the laser output power Po can be determined using the equations (1) and (2).

The arithmetic processing section 17 instructs the laser output control section 18. The laser output control unit 18 controls the voltage, gas pressure, etc. applied to the working light source 1 in order to obtain the instructed laser output power Po.

By varying the voltage and gas pressure, a desired laser output power Po can be generated. This may be done by determining the relationship between the voltage, gas pressure, and other parameters and the laser output power PO in advance, and then setting the parameter values for the desired PO.

Further, it may be provided with means for detecting the laser output power Po, and the target value and the measured value may be compared, and the parameters such as voltage and gas pressure may be automatically controlled to be varied in a direction to reduce the difference.

Describe the effect.

The operator decides whether to use a mirror waveguide or a fiber waveguide depending on the size and shape of the object and the situation between the object and the laser light source. The switching mirror 5 and the like are operated.

Then, the working power Pw necessary for this work is given to the waveguide tip output instruction section 16. The waveguide identification unit 15 identifies the type of waveguide, and the arithmetic processing unit 17 calculates the laser output power Po for the waveguide from the working power Pw.

The laser output control section 18 controls the working light source 1 to generate this laser output power Po. When exiting the light source, P
o decreases by the transmission efficiency while passing through the waveguide, so the power at the exit of the waveguide becomes equal to the initially applied working power Pv.

Describe the effects.

(1) Light from a high-output infrared working light source, such as an acetic acid gas laser, can be transmitted using either a mirror waveguide or a fiber waveguide. Moreover, since it is possible to specify the power PW of the working light that appears at the exit of the waveguide,
Desired power can be obtained in the cylinder. Work safely,
You can proceed reliably and quickly.

(2) Even when the waveguide is switched depending on the state of the target object, the laser output power PO is automatically controlled, and the desired working power Pw can be continuously obtained.

INDUSTRIAL APPLICATION This invention can be utilized for a laser treatment apparatus, a laser processing apparatus, etc.

Of course, the transmission efficiency axis of the mirror waveguide and the transmission efficiency ηf of the fiber waveguide vary. However, the fluctuation is slight, and even if there is a change over time, it is at most 1 to several percent. Therefore, it is possible to always irradiate the target object with laser light at the required working power within an error range of several percent.

This is a useful invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a laser device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a mirror waveguide according to a conventional example. FIG. 3 is a schematic diagram of a conventional fiber waveguide. 1 ・・・・・・ Work light source 2
...... Guide light source 3 ...... Mirror waveguide 4 ...
...... Fiber waveguide 5 ...... Switching mirror 11 ...... Working light fiber 12 ...... Guide light fiber 15 ... ...... Waveguide identification section 16 ・
... Waveguide tip output instruction section 17 ...
...... Performance processing section 18 ...... Laser output control section PO.
...... Laser output control section PW...
...Working power

Claims (1)

[Claims] Each waveguide is equipped with a working light source such as an infrared laser, a guide light source such as a visible laser, and a mirror waveguide and a fiber waveguide to be used alternatively for guiding the working light and the guide light. A calculation processing unit that calculates the necessary laser output power PO from the transmission coefficient of and a desired working power Pw at the tip of the waveguide, and a laser output control unit that controls the working light source that produces this laser output power PO A laser device characterized by: