GAS LASER

Abstract

A gas laser, including: a semiconductor laser, an optical beam-shaping system, a pair of electrodes, a discharge tube, a rear mirror, and an output mirror. The pair of electrodes includes two electrodes. The electrodes are symmetrically disposed at an outer layer of the discharge tube in parallel. The electrodes are connected to a radio-frequency power supply via a matching network, and the electrodes operate to modify working gas in the discharge tube through radio-frequency discharge. The rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively. The rear mirror, taken together with the output mirror and the discharge tube, form a resonant cavity. The output mirror is configured to output a laser beam.

Claims

1. A gas laser, comprising: a semiconductor laser; an optical beam-shaping system; a pair of electrodes comprising two electrodes; a discharge tube; a rear mirror; and an output mirror; wherein the two electrodes are symmetrically disposed in parallel at an outer layer of the discharge tube; the two electrodes are connected to a radio-frequency power supply via a matching network, and are configured to perform radio-frequency discharge on working gas in the discharge tube; the rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively; the rear mirror, the output mirror, and the discharge tube form a resonant cavity; the output mirror is configured to output a laser beam; an outer wall of the discharge tube in the vicinity of the optical beam-shaping system is coated with a transmission film; the transmission film is conformity to pump light in size and shape; the rest of the outer wall is coated with a reflection film, and an inner wall of the discharge tube is uncoated, or coated with another transmission film; the discharge tube is filled with the working gas; and the working gas is rare gas, or a mixture of rare gas and assistant gas; the semiconductor laser is configured to produce pump light; the optical beam-shaping system is configured to concentrate the pump light to form a narrow strip facula; the facula is allowed to pass through the transmission film on the outer wall of the discharge tube and is injected in the discharge tube; and a central wavelength of the pump light matches with an absorption line of gas particles produced by the radio-frequency discharge of the working gas in the discharge tube.

2. The laser of claim 1, wherein the working gas in the discharge tube is a mixture of argon and helium, and a pressure thereof is between 0.5 and 2.0 atmosphere; a volume ratio of the argon to the helium is between 1:50 to 1:4.

3. The laser of claim 1, wherein the working gas in the discharge tube is neon, argon, krypton, xenon, a mixture of the neon and helium, a mixture of the argon and the helium, a mixture of the krypton and the helium, a mixture of the xenon and the helium, or a mixture of the neon, the argon, the krypton, the xenon, the helium, and other assistant gas.

4. The laser of claim 2, wherein the working gas in the discharge tube is neon, argon, krypton, xenon, a mixture of the neon and the helium, a mixture of the argon and the helium, a mixture of the krypton and the helium, a mixture of the xenon and the helium, or a mixture of the neon, the argon, the krypton, the xenon, the helium, and other assistant gas.

5. The laser of claim 1, wherein the pair of electrodes is aluminum or copper; and contact surfaces of the pair of electrodes and the discharge tube are flat surfaces, or curved surfaces which match with the outer wall of the discharge tube.

6. The laser of claim 2, wherein the pair of electrodes is aluminum or copper; and contact surfaces of the pair of electrodes and the discharge tube are flat surfaces, or curved surfaces which match with the outer wall of the discharge tube.

7. The laser of claim 1, wherein a water-cooling channel is disposed in the pair of electrodes.

8. The laser of claim 2, wherein a water-cooling channel is disposed in the pair of electrodes.

9. The laser of claim 1, wherein a shielding chamber is disposed at an outer side of the pair of electrodes; the shielding chamber is made of metal materials; the shielding chamber is filled with gas with ionization potential, or the shielding chamber is vacuumed; and the shielding chamber is provided with a shielding chamber window at a position relative to the semiconductor laser, and the shielding chamber window allows the pump light to transmit.

10. The laser of claim 2, wherein a shielding chamber is disposed at an outer side of the pair of electrodes; the shielding chamber is made of metal materials; the shielding chamber is filled with gas with ionization potential, or the shielding chamber is vacuumed; and the shielding chamber is provided with a shielding chamber window at a position relative to the semiconductor laser, and the shielding chamber window allows the pump light to transmit.

11. The laser of claim 1, wherein a gas inlet and a gas outlet are disposed in the discharge tube; and an external pipeline between the gas inlet and the gas outlet is connected to a fan and a heat exchanger in series.

12. The laser of claim 2, wherein a gas inlet and a gas outlet are disposed in the discharge tube; and an external pipeline between the gas inlet and the gas outlet is connected to a fan and a heat exchanger in series.

13. The laser of claim 9, wherein a gas inlet and a gas outlet are disposed in the discharge tube; and an external pipeline between the gas inlet and the gas outlet is connected to a fan and a heat exchanger in series.

14. The laser of claim 10, wherein a gas inlet and a gas outlet are disposed in the discharge tube; and an external pipeline between the gas inlet and the gas outlet is connected to a fan and a heat exchanger in series.

15. The laser of claim 1, wherein a plurality of the discharge tubes is connected in series in the shielding chamber; and pairs of the electrodes on the outer wall of adjacent discharge tubes are mutually perpendicular.

16. The laser of claim 2, wherein a plurality of the discharge tubes is connected in series in the shielding chamber; and pairs of the electrodes on the outer wall of adjacent discharge tubes are mutually perpendicular.

17. The laser of claim 9, wherein a plurality of the discharge tubes is connected in series in the shielding chamber; and pairs of the electrodes on the outer wall of adjacent discharge tubes are mutually perpendicular.

18. The laser of claim 10, wherein a plurality of the discharge tubes is connected in series in the shielding chamber; and pairs of the electrodes on the outer wall of adjacent discharge tubes are mutually perpendicular.

19. The laser of claim 1, wherein the discharge tube is cylindrical.

20. The laser of claim 2, wherein the discharge tube is cylindrical.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention is described hereinbelow with reference to the accompanying drawings, in which:

[0031] FIG. 1 is an end face diagram of a gas laser in accordance with one embodiment of the invention;

[0032] FIG. 2 is a semi-sectional view of a gas laser in accordance with one embodiment of the invention;

[0033] FIG. 3 is a schematic diagram of a shielding chamber of a gas laser in accordance with one embodiment of the invention;

[0034] FIGS. 4A and 4B are schematic diagrams of a discharge tube of a gas laser in accordance with one embodiment of the invention;

[0035] FIG. 5 is a schematic diagram showing a gas circulation in a gas laser in accordance with one embodiment of the invention; and

[0036] FIG. 6 is a diagram showing that a plurality of discharge tubes is connected in series in a gas laser in accordance with one embodiment of the invention.

[0037] In the drawings, the following reference numbers are used: 1. Semiconductor laser; 2. Optical beam-shaping system; 3. Shielding chamber window; 4. Pair of electrodes; 5. Discharge tube; 6. Shielding chamber; 7. Matching network; 8. Radio-frequency power supply; 9. Rear mirror; 10. Output mirror; 11. Output laser; 12. High-transmission film; 13. High-reflection film; 14. Gas inlet; 15. Gas outlet; 16. Fan; and 17. Heat exchanger.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] For further illustrating the invention, experiments detailing a gas laser are described below. It should be noted that the following examples are intended to describe and not to limit the invention.

[0039] The working mode of the gas laser is as follows:

[0040] As shown in FIGS. 1-5, in the example, a gas laser comprises a semiconductor laser 1 as a pumping source, an optical beam-shaping system 2, a pair of electrodes 4, a discharge tube 5 which is coated with a high-transmission film 12 and a high-reflection film 13, a shielding chamber 6, a rear mirror 9, an output mirror 10, a gas inlet 14, a gas outlet 15, a fan 16, a heat exchanger 17, a matching network 7, and a radio-frequency power supply 8 which is connected to the pair of electrodes 4 via the matching network 7. Coating technique is applied on the discharge tube 5, so that the pump light is fully injected into the discharge tube 5, and the discharge tube 5 features high-reflection characteristics for the pump light. A part of an outer surface of the discharge tube 5 is coated with the high-transmission film 12, and the pump light is fully injected in the discharge tube 5. The rest of the outer surface of the discharge tube is coated with the high-reflection film 13, and an inner wall of the discharge tube 5 is uncoated, or coated with another high-transmission film 12, thus the discharge tube 5 features high-reflection characteristics for the pump light, and a multi-pass reflection process of the pump light which is similar to the blackbody absorption in the discharge tube is realized. A collision probability of the pump light and the gas particles which experienced radio-frequency discharge in the discharge tube 5 is increased, and a pump efficiency and a pump quality of the gas laser is improved, in addition, the output power of the laser is increased. The working gas in the discharge tube 5 is single rare gas, a mixture of two rare gases, or a mixture of rare gases and other assistant gas, thus the working gas is poisonless, harmless, and stable in chemical characteristic. The water-cooling channel is disposed in the pair of electrodes 4. The water-cooling channel is configured to cool the pair of electrodes 4 during the high-power laser output process, and reduce deformation of the pair of electrodes, thus ensuring the stability of the radio-frequency discharge. The pump light is concentrated by the optical beam-shaping system 2 to form a narrow strip facula, and is fully injected into the discharge tube 5, therefore, the pump efficiency of the laser system is improved. The shielding chamber 6 is an air-tight chamber, and the discharge tube and the pair of electrodes are sealed in the air-tight shielding chamber. The shielding chamber is filled with gas with high ionization potential, or the shielding chamber is vacuumed, so as to avoid breakdown of the gas outside of the discharge tube due to high discharge voltage, thus improving the stability and uniformity of the radio-frequency discharge during the high-power laser output, and preventing pollution to the environment caused by radio-frequency radiation. The rear mirror 9 and the output mirror 10 are disposed at two ends of the discharge tube 5, respectively. The rear mirror and the output mirror form a resonant cavity. A gas inlet 14 and a gas outlet 15 are disposed in the discharge tube 5, and an external pipeline between the gas inlet and the gas outlet is connected to a fan 16 and a heat exchanger 17 in series, thus a circulation of the working gas is built in the discharge tube 5, and unwanted heat is reduced during the laser output process, in addition, the stability of the laser is ensured, and the output power of the laser is enhanced.

[0041] In conclusion, a gas laser which effectively outputs ultra-high power laser that features high laser beam quality is provided in the embodiment of the invention.

[0042] Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.