WO1999038234A1 - Oscillateur a laser a gaz et dispositif de traitement a laser a gaz - Google Patents

Oscillateur a laser a gaz et dispositif de traitement a laser a gaz Download PDF

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Publication number
WO1999038234A1
WO1999038234A1 PCT/JP1998/000249 JP9800249W WO9938234A1 WO 1999038234 A1 WO1999038234 A1 WO 1999038234A1 JP 9800249 W JP9800249 W JP 9800249W WO 9938234 A1 WO9938234 A1 WO 9938234A1
Authority
WO
WIPO (PCT)
Prior art keywords
laser
gas
mirror unit
laser beam
laser oscillator
Prior art date
Application number
PCT/JP1998/000249
Other languages
English (en)
Japanese (ja)
Inventor
Yushi Takenaka
Junichi Nishimae
Yukio Satoh
Original Assignee
Mitsubishi Denki Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Denki Kabushiki Kaisha filed Critical Mitsubishi Denki Kabushiki Kaisha
Priority to PCT/JP1998/000249 priority Critical patent/WO1999038234A1/fr
Priority to TW087101451A priority patent/TW385581B/zh
Publication of WO1999038234A1 publication Critical patent/WO1999038234A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/034—Optical devices within, or forming part of, the tube, e.g. windows, mirrors
    • H01S3/0346—Protection of windows or mirrors against deleterious effects
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/036—Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube

Definitions

  • the present invention relates to a gas laser oscillator for obtaining a high output and extracting a stable laser beam, and a gas laser processing apparatus using the same.
  • Fig. 9 (a) is a cross-sectional view of a three-axis orthogonal CO 2 laser oscillator shown in Fig. 3.5 (b) on page 45, for example, by laser processing technology (by Hiromichi Kawasumi, Nikkan Kogyo Shinbunsha). It is.
  • FIG. 9B is a cross-sectional view taken along line AA of FIG. 9A.
  • la and 1 b are a pair of discharge electrodes for exciting the laser gas
  • 2 is a blower for circulating the laser gas
  • 3 is a heat exchanger for cooling the laser gas heated by the discharge excitation
  • 4 is a discharge electrode la
  • This is the discharge excitation unit that houses the lb, blower 2, and heat exchanger 3.
  • Reference numeral 5 denotes a laser medium excited by discharge at the discharge electrodes la and lb.
  • a gas laser such as a C02 laser, it is a gas medium.
  • 6 is a concave partial reflection mirror made of, for example, ZnSe
  • 7 is a concave total reflection mirror made of, for example, Cu.
  • the partial reflection mirror 6 and the total reflection mirror 7 are arranged to face each other to form a stable laser resonator.
  • 8a and 8b are mirror units for holding the resonator mirrors 6 and 7, respectively.
  • Reference numeral 9 denotes a laser beam generated in the laser resonator
  • 10 denotes a laser beam extracted from the CO 2 laser oscillator by the partially reflected mirror 16.
  • the laser beam 9 is connected to the discharge excitation section 4 Between the partial reflection mirror 16 and the total reflection mirror 7 held by the mirror unit portions 8a and 8b, respectively, and during this reciprocation, the laser medium 5 excited by discharge between the discharge electrodes 1a and lb. Amplified. After the laser beam 9 is amplified in this way, a part of the laser beam 9 passes through the partial reflection mirror 16.
  • the laser beam 10 extracted outside the C ⁇ 2 laser oscillator is used for processing an iron plate or the like.
  • the laser medium 5 has heat when excited by discharge at the discharge electrodes 1a and 1b, and this heat is cooled by circulating the laser gas through the blower 2 and passing through the heat exchanger 3.
  • FIG. 10 shows laser oscillation characteristics obtained when the transmittance of the partial reflection mirror 16 predicted from the oscillation theory of the laser is changed.
  • the discharge power (threshold power) at which laser oscillation starts is smaller than that with high transmittance, so that the laser output increases as a result when compared with the same discharge power. Therefore, it is clear that increasing the output of the laser without changing the size of the casing of the C ⁇ ⁇ ⁇ 2 laser oscillator can be realized by reducing the transmittance of the partial reflection mirror-6.
  • the conventional CO 2 laser oscillator is configured as described above.
  • the laser beam 9 is amplified in the discharge excitation section 4 but is absorbed in the mirror unit sections 8a and 8b. Since the laser gas is sealed in the discharge excitation section 4, the mirror units 8a and 8b, and the resonator mirrors 6 and 7, the laser gas is also sealed in the mirror units 8a and 8b.
  • the laser gas will be present. When the laser gas is discharged and excited by the discharge electrodes 1a and 1b, it becomes a laser medium 5 that amplifies the laser beam 9, but has an action of absorbing the laser beam 9 when not discharged.
  • FIG. 11 shows the laser oscillation characteristics obtained when the transmittance of the partial reflection mirror 16 is changed. From the results in Fig. 11, when the transmittance is reduced, the laser oscillation characteristics begin to bend, and the laser output is reversed at a certain input power, and the higher the transmittance, the better. In order to eliminate the bending of the laser oscillation characteristics shown in FIG. 11 and obtain the laser oscillation characteristics that match the predicted characteristics as shown in FIG. 10, the laser beam generated in the mirror unit 8 is required. It is necessary to eliminate absorption of system 9. Disclosure of the invention
  • An object of the present invention is to obtain a laser oscillation characteristic in which a laser output does not bend even if the transmittance of a partially reflecting mirror is small by eliminating absorption of a laser beam in a mirror unit.
  • a gas laser oscillator includes: a pair of discharge electrodes for exciting a laser gas to generate a laser beam; a mirror unit provided on both sides of the discharge electrode and having at least a pair of mirrors for reflecting the laser beam; And a mechanism for forcibly moving the laser gas present in the optical path of the laser beam out of the optical path.
  • the laser gas present in the optical path of the laser beam in the mirror unit is forcibly moved out of the optical path, it is possible to eliminate the absorption of the laser beam, so that even if the transmittance of the partial reflection mirror is small, High output laser oscillation characteristics without bending can be obtained.
  • the gas laser oscillator of the present invention is preferably provided with a blower in the mirror unit for forcibly moving the laser gas out of the optical path. Blower installed Since it is provided in the mirror unit, high output can be realized without increasing the size of the device.
  • the gas laser oscillator of the present invention preferably includes a gas conduit connected to the mirror unit, and a blower for moving the laser gas through the gas conduit. Since the laser gas is moved out of the optical path by the blower and the gas conduit, the absorption of the laser beam in the mirror unit can be eliminated.
  • a high-power laser oscillator can be obtained without increasing the size of the device.
  • the gas laser oscillator of the present invention has a gas conduit communicating with the mirror unit and the discharge excitation unit, and a blower for moving the laser gas through the gas conduit, and the blower is provided in the discharge excitation unit, It is also preferable that the device also serves as a blower for circulating the laser gas heated by the excitation. Since the laser gas is moved outside the optical path by the blower and the gas conduit, absorption of the laser beam in the mirror unit can be eliminated. In addition, the blower also serves as a blower for circulating the laser gas heated by the discharge excitation, so that high output can be realized without increasing the size of the device.
  • the gas laser oscillator of the present invention may have a plurality of optical paths of the laser beam in the discharge excitation unit and the mirror unit. Since there are multiple laser beam paths, high output can be obtained without increasing the size of the device.
  • the gas laser processing device of the present invention relates to a device that transmits a laser beam generated from the above-described gas laser oscillator of the present invention and irradiates a workpiece. Since the laser beam generated by the gas laser oscillator of the present invention is used, it is possible to perform processing with a high-power laser beam without bending. In addition, the size of the caroe apparatus can be reduced.
  • 1 (a) and 1 (b) are cross-sectional views showing one embodiment of a laser gas oscillator according to the present invention.
  • FIG. 2 is a diagram illustrating laser oscillation characteristics of the gas laser oscillator of FIG.
  • FIG. 3 is a cross-sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 4 is a cross-sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 5 is a cross-sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 6 is a sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 7 is a cross-sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 8 is a sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • FIG. 9 is a cross-sectional view showing an example of a conventional gas laser oscillator.
  • FIG. 10 is a diagram showing predicted oscillation characteristics of a gas laser.
  • FIG. 11 is a diagram showing laser oscillation characteristics of a conventional gas laser oscillator. BEST MODE FOR CARRYING OUT THE INVENTION
  • FIG. 1A is a cross-sectional view of an example of the carbon dioxide laser oscillator of the present invention.
  • FIG. 1B is a cross-sectional view taken along line BB of FIG. 1A.
  • la 1 b is a pair of discharge electrodes for exciting the laser gas
  • 2 is a blower for circulating the laser gas
  • 3 is a heat exchanger for cooling the laser gas heated by the discharge excitation
  • 4 is a discharge electrode la, lb, blower 2
  • Reference numeral 5 denotes a laser gas medium excited by discharge by the discharge electrodes la and 1b.
  • 6 is a concave partial reflection mirror made of ZnSe
  • 1 is a concave total reflection mirror made of Cu.
  • the partial reflection mirror 6 and the total reflection mirror 7 are arranged to face each other to form a stable laser resonator.
  • Reference numerals 8a and 8b denote mirror units for holding the resonator mirrors 6 and 7, respectively.
  • Reference numeral 9 denotes a laser beam generated in the laser resonator, and reference numeral 10 denotes a laser beam taken out of the C ⁇ 2 laser oscillator by the partial reflection mirror 16.
  • 11 and 12 are gas blowers installed inside the mirror units 8a and 8b.
  • the gas laser oscillator is a triaxial orthogonal CO 2 laser oscillator. If the gas blowers 11 and 12 do not operate, the laser beam 9 will be absorbed by the laser gas existing in the mirror unit sections 8a and 8b, and the partial reflection mirror 16 will be used similarly to the conventional CO 2 laser oscillator. If the transmittance is reduced, the laser oscillation characteristics will bend.
  • the gas blowers 11 and 12 when the gas blowers 11 and 12 are operated, the laser gas which stays in the laser beam paths of the mirror units 8a and 8b and absorbs the laser beam 9 has been used. Before the laser beam 9 is sufficiently absorbed, the laser beam 9 is caused to flow out of the optical path of the laser beam.
  • FIG. 2 shows the laser oscillation characteristics measured when the gas blowers 11 and 12 were operated. As can be seen from a comparison between FIG. 2 and FIG. 11, the bending of the laser oscillation characteristics was almost improved, and the prediction shown in FIG. High-output laser oscillation characteristics that match well with the characteristics can be obtained. Since the gas blowers 11 and 12 are installed in the existing mirror unit sections 8a and 8b, there is no need to change the size of the housing of the gas laser oscillator, so that the apparatus configuration does not need to be enlarged.
  • a laser using a stable resonator has been described as a laser resonator constituting a gas laser oscillator.
  • the present invention is not limited to this, and the same effect can be obtained even with an unstable resonator.
  • Fig. 1 describes the case where the gas blowers 11 and 12 are installed so that they are perpendicular to the horizontal direction with respect to the laser light
  • Fig. 3 shows the case where the gas blowers 11 and 12 are perpendicular to the laser light. In this case, it is installed at a right angle to it.
  • the operation is the same as that in Fig. 1.
  • the laser gas is circulated or diffused along the flow direction 21 by the operation of the gas blowers 11 and 12, so that the mirror units 8a and 8b
  • the absorption that has occurred is almost eliminated, the laser oscillation characteristics no longer bend, and the same high-output oscillation characteristics as in Fig. 2 are obtained.
  • Fig. 1 shows the case where one gas blower 11 and 12 are installed in each mirror unit 8a and 8b, respectively.However, in order to further increase the air volume, the mirror unit 8a is installed as shown in Fig. 4. The same effect can be obtained even if two units are installed in each of 8b and 8b. In order to further increase the air volume, multiple units may be installed in the mirror units 8a and 8b.
  • FIG. 5 is a sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • 4 1 a, 4 1 b, 4 1 c, 4 1 d are discharge unit 4 and mirror unit This is a gas conduit connecting parts 8a and 8b.
  • the gas circulates and flows in the direction of the arrow through the gas conduits 41a to 41d.
  • the gas flow 21 circulates or diffuses the laser gas existing in the optical path of the laser beams of the mirror units 8a and 8b and moves the laser gas out of the optical path.
  • FIG. 6 is a sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • Reference numeral 51 denotes a blower for circulating gas in the direction of the arrow between the discharge excitation unit 4 and the mirror units 8a and 8b via the gas conduits 41a to 41d.
  • a gas flow 21 in the direction of the arrow that moves the blower 51 is generated, and the laser gas existing in the optical path of the laser beam in the mirror units 8a and 8b is circulated or diffused and moved out of the optical path.
  • the absorption of the laser beam in the mirror unit sections 8a and 8b is eliminated, and a high-output laser oscillation characteristic without bending is obtained as shown in FIG.
  • FIG. 7 is a sectional view showing another embodiment of the gas laser oscillator of the present invention.
  • the resonator has a Z-shaped folded configuration using folded mirrors 61 and 62, and the mirror unit sections 8a and 8b have a plurality of optical paths of the laser beam.
  • the laser gas is moved out of the optical path of the laser beams of the mirror units 8a and 8b.
  • absorption of the laser beam by the mirror unit units 8a and 8b is eliminated, and as shown in FIG. High output laser oscillation characteristics without bending are obtained.
  • the effect of the present invention that is, the absorption of the laser beam, can be obtained in this embodiment. It will be even bigger.
  • FIG. 8 shows an example of a CO 2 laser processing apparatus equipped with the gas laser oscillator described in the first embodiment.
  • reference numeral 81 denotes a gas laser oscillator
  • reference numeral 82 denotes a beam duct made up of beam ducts 83a, 83b and bend mirrors 84a, 84b, 84c, 84d, etc.
  • a beam transmission system for transmitting the laser beam 10 generated from 1, 8 5 is a processing lens 8 7 for condensing the laser beam 10 on the workpiece 8 6, and an assist gas pipe 8 8
  • a processing head composed of a nozzle 89 for blowing the assist gas to be blown onto the workpiece 86, and 90 is a processing table for moving the workpiece 86.
  • 9 1a and 9 1b are water tubes.
  • a high-power and stable laser beam can be supplied from the gas laser oscillator 81, so that laser processing can be performed with high quality and at high speed.
  • the gas laser oscillator of the present invention is not limited to this, and a discharge-excited gas laser, For example, similar effects can be obtained by applying the present invention to an excimer laser or a metal vapor laser.
  • the case where the present invention is applied to a three-axis orthogonal gas laser oscillator has been described.
  • the gas laser oscillator of the present invention is not limited to this. The same effect can be obtained even when applied to an axial flow type gas laser oscillator.
  • the mechanism for forcibly moving the laser gas existing in the optical path of the laser beam in the mirror unit to the outside of the optical path is provided, so that the absorption of the laser beam in the mirror unit is eliminated.
  • high-output laser oscillation characteristics without bending can be obtained.
  • a blower is installed in the mirror unit as a mechanism for forcibly moving the laser gas, high-output laser oscillation characteristics can be obtained without increasing the size of the device.
  • a gas conduit connected to the mirror unit and a blower for moving the laser gas through the gas conduit can be used, and a high-output device without increasing the size of the device can be used. Laser oscillation characteristics can be obtained.
  • the blower also serves as a blower that circulates the laser gas heated by the discharge excitation in the discharge excitation section, the device configuration can be further downsized.
  • the effect of obtaining high-output laser oscillation characteristics is further enhanced by providing a mechanism to forcibly move the laser gas from the laser beam path.
  • gas laser processing apparatus of the present invention uses the above-described gas laser oscillator, processing can be performed with a high-output laser beam without increasing the size of the apparatus.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Lasers (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)

Abstract

L'invention concerne un oscillateur à laser à gaz, qui possède une puissance élevée et émet un faisceau laser stable, et un dispositif de traitement utilisant cet oscillateur à laser à gaz. L'oscillateur à laser à gaz possède une partie d'excitation par décharges (5) qui comporte au moins une paire d'électrodes de décharge (1a, 1 b), des parties d'unités de miroirs (8a, 8b) qui renferment les miroirs du résonateur et sont reliées à la partie d'excitation par décharges et des soufflantes de gaz (11, 12) situées à l'intérieur ou à l'extérieur des parties d'unités de miroirs. Dans l'oscillateur à laser à gaz qui possède cette structure, on peut éliminer l'absorption des faisceaux laser générés dans les parties d'unités de miroirs en faisant circuler au moyen des soufflantes de gaz (11, 12) les gaz laser se trouvant dans lesdites parties d'unités de miroirs (8a, 8b).
PCT/JP1998/000249 1998-01-22 1998-01-22 Oscillateur a laser a gaz et dispositif de traitement a laser a gaz WO1999038234A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP1998/000249 WO1999038234A1 (fr) 1998-01-22 1998-01-22 Oscillateur a laser a gaz et dispositif de traitement a laser a gaz
TW087101451A TW385581B (en) 1998-01-22 1998-02-06 CO2 gas laser oscillator and gas laser processing machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1998/000249 WO1999038234A1 (fr) 1998-01-22 1998-01-22 Oscillateur a laser a gaz et dispositif de traitement a laser a gaz

Publications (1)

Publication Number Publication Date
WO1999038234A1 true WO1999038234A1 (fr) 1999-07-29

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PCT/JP1998/000249 WO1999038234A1 (fr) 1998-01-22 1998-01-22 Oscillateur a laser a gaz et dispositif de traitement a laser a gaz

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WO (1) WO1999038234A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7262217B2 (ja) * 2018-12-17 2023-04-21 住友重機械工業株式会社 光共振器

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6375061U (fr) * 1986-11-06 1988-05-19
JPH01214185A (ja) * 1988-02-23 1989-08-28 Toshiba Corp パルスレーザ発振装置
JPH038380A (ja) * 1989-06-06 1991-01-16 Amada Co Ltd レーザ発振器の内部ミラー保護方法およびその装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6375061U (fr) * 1986-11-06 1988-05-19
JPH01214185A (ja) * 1988-02-23 1989-08-28 Toshiba Corp パルスレーザ発振装置
JPH038380A (ja) * 1989-06-06 1991-01-16 Amada Co Ltd レーザ発振器の内部ミラー保護方法およびその装置

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TW385581B (en) 2000-03-21

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