JPH0259192A - Laser beam equipment with large power - Google Patents

Abstract

PURPOSE:To obtain a laser beam equipment capable of producing a large power easily and at a low cost by adding up laser beams obtained from plural laser beam oscillators with small power each having different optical axes and reforming them into laser beams having the same optical axis. CONSTITUTION:A wave guide system 30 has plural incident holes 24 of beams these beam paths are concentrated upon one path at the branch point 25 of the wave guide in the central part of the wave guide system to connect with the outgoing hole 26. The laser beams 21 obtained from plural oscillators with small power are injected by reflective mirrors 2 into the wave guide system 30 through the direction of incident holes 24. The beams 21 are condensed by condenser optical systems 23 into the incident holes 24. The original system 23 is composed of a single lens of ZnSe for the CO2 laser beam. The beams 21 condensed at the incident hole 24 repeats multiple reflections in the wave guide 30 and advanced toward the side of the emitting hole 26. Besides, the loss of beam in the wave guide 30 of the beams emitted from the wave guide system 30 is about 15% per one laser beam 21.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a high output laser device.

[Conventional technology]

Conventionally, the continuous wave output of CO2 lasers has been limited to about 20 kW. In addition, in Nd; YAG laser, YA
There is a limit to the manufacturing dimensions of the G rod, and the laser output that can be extracted from one rod is about 300 W. In order to increase the output, YAG rods were connected in series as shown in Figure 3. In the same figure, 11 is Nd; YAG o y
12 is a Kr rande, 13 is a total reflection mirror, and 14 is a semi-transmission mirror. However, as the number of rods 11 increases, it becomes difficult to align the laser beam, and in practice, as shown in Figure 4, which shows the relationship between oscillation output and beam expansion angle, 1 or 2 kW with four rods is a large output. This had become the limit of its development.

[Problem to be solved by the invention]

In order to increase the output in a conventional oscillator, Co2 lasers use transmission type optical components such as Zn5e, so if a certain limit is exceeded, thermal distortion occurs in the components, and the beam divergence angle decreases due to the thermal lens effect. This causes a problem in that the light collection performance deteriorates. Furthermore, if the output is increased even further,
Transparent optical components will be destroyed by beam absorption.

On the other hand, in YAG lasers, high output is achieved by connecting multiple rondos in series, but as the laser output increases, the beam spreads and the υ angle also increases as shown in Figure 4. Due to optical alignment, the number of rods that can be connected in series is limited to four, which limits the oscillation output to about 1.2 kW, making it impossible to support higher output.

[Means to solve the problem]

The present invention uses a branched Cu waveguide having multiple entrance holes and one exit hole, and increases the output by combining small output beams oscillated by multiple oscillators within the waveguide and then taking them out. Alternatively, the oscillation beam obtained from one oscillator is shaped into a ring-shaped beam by an axicon lens and focused by a hollow mirror and a hollow lens, while the oscillation beam obtained from other oscillators is shaped into a ring-shaped beam by a condensing lens. The beams obtained from a plurality of oscillators are condensed and combined on the same optical axis to achieve high output.

[Effect]

In the device using a waveguide as described above, nine beams obtained from multiple oscillators travel through the gold-coated waveguide from multiple entrance holes while undergoing multiple reflections, and are summed at a gathering point to increase the output. The light is emitted from one emitting hole and used for processing, etc.
On the other hand, in the case of using an axicon lens, by making the oscillation beam hollow using two axicon lenses, the beam obtained from another oscillator is guided to the hollow part, and the hollow beam is focused into the hollow part. The light is focused by an optical lens, and the beam that enters the hollow part is focused by a normal lens to achieve high output.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows its configuration, where 21 is the oscillation beam, 2
2 is a reflecting mirror, 23 is a condensing lens optical system, 24 is a beam entrance hole, 25 is a waveguide branch point, 26 is a beam exit hole,
27 is the water inlet, 28 is the water outlet, 29 is the gold coated surface,
30 is a waveguide system. The waveguide system 31 has a plurality of beam entrance holes 24 , and the beam paths are converged into one at a waveguide branch point 25 in the center of the waveguide system and communicate with an exit hole 26 . Laser beams 21 obtained from a plurality of oscillators are incident on this waveguide system 30 by a reflecting mirror 22 toward the entrance hole 24 . This laser beam 21 is condensed into an entrance hole 24 by a condensing lens optical system 23 . This condensing lens optical system 23 is Z in the case of a Co2 laser.
It is composed of a single lens made of n5e, and in the case of a YAG laser, it is composed of a plurality of quartz-based (BSC7) lenses. The beam 21 focused on the waveguide entrance hole 24 repeats multiple reflections within the waveguide 30 and travels toward the exit hole 26 side.

The waveguide system 3Q is made of copper, and the inner surface of the waveguide 3o is coated (29) with gold to increase reflectance.

In addition, in order to suppress heat generation due to beam absorption in the waveguide 3σ, the outer periphery of the waveguide 30 has a water-cooled structure, and the water inlet 27,
It has an outlet 28. The beam loss within the waveguide 30 of the beam emitted from this waveguide 30 system is about a factor of 15 for one laser beam.

FIG. 2 shows another configuration example in which a hollow beam is created using an axicon lens and the output is increased.

A laser beam 31 obtained from an oscillator output mirror 41 is split into a ring-shaped beam 44 by a concave axicon lens 43 . This divided beam 44 is collimated by a convex axicon lens 45 and becomes a laser beam 46 with little spread.

This laser beam 46 is directed toward the processing surface by a hollow mirror 47 to become a hollow condensed beam 49, and the hollow condensing beam 49 is focused onto the processing surface 20 by a hollow condenser lens 48. On the other hand, the depim 31 is directed toward the processing surface by a normal reflecting mirror 32, and is condensed by a condensing lens 33 while passing through the hollow portions of a hollow mirror 47 and a hollow condensing lens 48 to form a condensed beam 12. The light is focused at the same position as the focusing point of the hollow focusing lens 48, that is, at the processing surface 50. This results in high output.

〔Effect of the invention〕

As described in detail above, according to the present invention, in order to obtain high output without increasing the oscillation output, the limit for increasing the output is high, and the optical system using a plurality of oscillators is used. system), 24... Beam entrance hole, 25... Waveguide branch point, 26... Beam exit hole, 27... Water inlet, 28... Water outlet, 29... Now coated surface, 30
... Waveguide system, 41 ... Output mirror 42 ... Focused beam, 43 ... Concave axicon lens, 44.4
6...Hollow beam, 45...Convex axicon lens, 47...Hollow reflecting mirror 48...Hollow condenser lens, 49...Hollow condenser beam, 50...Processed surface .

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1(a) is a diagram showing the configuration, and FIG. s1(b) is the same diagram (&)
Fig. 2 is a diagram showing another configuration example, Fig. 3 is a diagram showing the configuration of a conventional YAG laser device, and Fig. 4 is the oscillation output of Fig. 3. FIG. 3 is a diagram showing the relationship between the beam divergence angle and the beam divergence angle. 11-Nd; YAG mouth, 12-・Kr Lande,
13... Total reflection mirror 14... Semi-transmission mirror 2
1.31...Oscillation beam, 22.32...Reflection mirror 23゜Applicant's representative Patent attorney Takehiko Suzue (
a) (b) Figure 2 Figure 1

Claims (3)

[Claims] (1) It is characterized by being equipped with a plurality of low-power laser oscillators having different optical axes, and an optical section that adds the laser beams obtained from these laser oscillators and reorganizes them into laser beams having the same optical axis. A high output laser device. (2) The optical section has a plurality of beam entrance holes on the laser beam incidence side, and the beams are combined in the middle of the waveguide, and the beam is emitted from one exit hole (
1) The high output laser device described. (3) A claim characterized in that the optical section uses an axicon lens to create a hollow laser beam intensity distribution, guide laser beams emitted from different laser oscillators into the hollow portion, and combine the beams. (1) The high output laser device described.