Laser chamber

Patent metadata

Field	Value
Publication number	US-9722385-B2
Application number	US-201615198433-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Feb 21, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A laser chamber for a discharge excited gas laser apparatus may include: a first discharge electrode disposed in the laser chamber; a second discharge electrode disposed to face the first discharge electrode in the laser chamber; a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode; a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode; a metallic damper member disposed upstream of the laser gas flow from the second discharge electrode; and a second insulating member disposed downstream of the laser gas flow from the second discharge electrode.

First claim

The invention claimed is:

1. A laser chamber for a discharge excited gas laser apparatus, comprising:
a first discharge electrode disposed in the laser chamber;
a second discharge electrode disposed to face the first discharge electrode in the laser chamber;
a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode;
a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode;
a first metallic damper member disposed upstream of the laser gas flow from the second discharge electrode;
a second metallic damper member disposed downstream of the laser gas flow from the second discharge electrode; and
a second insulating member disposed downstream of the laser gas flow from the second discharge electrode, and having a base end that contacts to a downstream side surface of the second discharge electrode, the second insulating member extending from the base end toward the downstream of the laser gas flow,
wherein the second metallic damper member has a tapered surface which tapers from the upstream to the downstream, and
the second insulating member is disposed on the tapered surface of the second metallic damper member, along the slope of the tapered surface.

2. The laser chamber according to claim 1 , wherein a concave part is formed in a surface of the second insulating member.

3. The laser chamber according to claim 2 , wherein:
the first discharge electrode and the second discharge electrode are each formed in a plate shape; and
the concave part is formed to extend and incline to a direction perpendicular to a longitudinal direction of the second discharge electrode.

4. The laser chamber according to claim 3 , wherein the first discharge electrode is a cathode electrode, and the second discharge electrode is an anode electrode.

5. The laser chamber according to claim 1 , wherein the surface of the second insulating member is flat.

6. The laser chamber according to claim 1 , wherein the second insulating member is formed to satisfy a following relationship:
(2 v/f )− L≦W≦c/ 2 f

where, f represents a repetition frequency of the discharge excited gas laser apparatus, c represents a velocity of acoustic waves generated by a discharge between the first discharge electrode and the second discharge electrode, v represents a flow velocity of the laser gas flow, L represents a width of the second discharge electrode in a flow direction of the laser gas flow, and W represents a width of the second insulating member in the flow direction of the laser gas flow.

7. The laser chamber according to claim 1 , wherein the second insulating member is disposed only downstream of the laser gas flow from the second discharge electrode.

8. The laser chamber according to claim 1 , wherein the second discharge electrode protrudes toward the first discharge electrode further than the second insulating member.

9. The laser chamber according to claim 2 , wherein the concave part is formed to extend and incline to a direction perpendicular to a longitudinal direction of the second discharge electrode.

10. The laser chamber according to claim 2 , wherein a cross-section of the concave part has a shape of triangular or sawtooth waves.

11. The laser chamber according to claim 2 , wherein a cross-section of the concave part has a shape of semicircular waves.

12. The laser chamber according to claim 2 , wherein the concave part includes hemispheric dimples.

13. The laser chamber according to claim 1 , wherein the second insulating member has a porous structure.

14. A laser chamber for a discharge excited gas laser apparatus, comprising:
a first discharge electrode disposed in the laser chamber;
a second discharge electrode disposed to face the first discharge electrode in the laser chamber;
a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode;
a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode;
a first metallic damper member disposed upstream of the laser gas flow from the second discharge electrode;
a second metallic damper member disposed downstream of the laser gas flow from the second discharge electrode; and
a second insulating member disposed on a surface of a portion of the second metallic damper member,
wherein the second metallic damper member contacts with the second discharge electrode at the portion, and
the second insulating member faces a discharge space formed between the first discharge electrode and the second discharge electrode.

15. The laser chamber according to claim 14 , wherein a concave part is formed in a surface of the second insulating member.

16. The laser chamber according to claim 14 , wherein the surface of the second insulating member is flat.

17. The laser chamber according to claim 14 , wherein the second insulating member is formed to satisfy a following relationship:
(2 v/f )− L≦W≦c/ 2 f

where, f represents a repetition frequency of the discharge excited gas laser apparatus, c represents a velocity of acoustic waves generated by a discharge between the first discharge electrode and the second discharge electrode, v represents a flow velocity of the laser gas flow, L represents a width of the second discharge electrode in a flow direction of the laser gas flow, and W represents a width of the second insulating member in the flow direction of the laser gas flow.

18. The laser chamber according to claim 14 , wherein the second insulating member is disposed only downstream of the laser gas flow from the second discharge electrode.

19. The laser chamber according to claim 14 , wherein the second discharge electrode protrudes toward the first discharge electrode further than the second insulating member.

20. The laser chamber according to claim 14 , wherein the second insulating member has a porous structure.

Assignees

• Gigaphoton Inc

Inventors

• Ikeda Hiroyuki
• Kakizaki Kouji
• Tsushima Hiroaki
• Katsuumi Hisakazu

Classifications

• H01S3/038 Primary

  Electrodes, e.g. special shape, configuration or composition · CPC title

• H01S3/2258

  F2, i.e. molecular fluoride is comprised for lasing around 157 nm · CPC title

• H01S3/0382

  Cathodes or particular adaptations thereof · CPC title

• H01S3/09702

  Details of the driver electronics and electric discharge circuits · CPC title

• H01S3/134

  in gas lasers · CPC title