Laser device and extreme ultraviolet light generation system

Patent metadata

Field	Value
Publication number	US-9743503-B2
Application number	US-201615202781-A
Country	US
Kind code	B2
Filing date	Jul 6, 2016
Priority date	Feb 10, 2014
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

An example laser apparatus of the disclosure may include an oscillator capable of outputting a laser beam, a slab optical amplifier capable of amplifying the laser beam outputted by the oscillator by passing the laser beam through an optical amplification region shaped like a slab and outputting the amplified laser beam, and a mirror disposed on an optical path of the laser beam to enter the slab optical amplifier or the amplified laser beam outputted from the slab optical amplifier, the mirror being movable in a direction parallel to a plane where the laser beam travels in the slab optical amplifier.

First claim

What is claimed is:

1. A laser apparatus comprising:
an oscillator capable of outputting a laser beam;
a slab optical amplifier capable of amplifying the laser beam outputted by the oscillator by passing the laser beam through an optical amplification region shaped like a slab and outputting the amplified laser beam; and
a mirror disposed on an optical path of the laser beam to enter the slab optical amplifier or the amplified laser beam outputted from the slab optical amplifier, the mirror being movable in a direction parallel to a plane where the laser beam travels in the slab optical amplifier.

2. The laser apparatus according to claim 1 , further comprising:
an optical path correction mechanism including the mirror, the optical path correction mechanism being capable of moving the mirror; and
a controller capable of controlling the optical path correction mechanism,
wherein the controller is configured to control the optical path correction mechanism to translate the mirror in a direction parallel to the plane where the laser beam travels to compensate for a translational component of a variation in optical path in the slab optical amplifier.

3. The laser apparatus according to claim 2 , further comprising:
a beam sampler disposed downstream of the slab optical amplifier and the mirror; and
a beam profiler capable of receiving a sample laser beam from the beam sampler,
wherein the controller is configured to:
acquire beam profile data from the beam profiler;
calculate a beam position from the acquired beam profile data; and
determine an amount to move the mirror based on a difference between the beam position and a reference beam position.

4. The laser apparatus according to claim 2 , further comprising:
a first beam sampler disposed downstream of the slab optical amplifier and the mirror;
a first beam profiler capable of receiving a sample laser beam from the first beam sampler;
a second beam sampler disposed downstream of the first beam sampler;
a second beam profiler capable of receiving a sample laser beam from the second beam sampler,
wherein the controller is configured to:
calculate a difference between a position of a beam observed by the first beam profiler and a first reference beam position;
calculate a difference between a position of a beam observed by the second beam profiler and a second reference beam position; and
determine an angular amount to tilt and an amount to translate the mirror based on the difference in the first beam profiler and the difference in the second beam profiler.

5. The laser apparatus according to claim 2 , further comprising:
a first beam sampler disposed downstream of the slab optical amplifier and the mirror;
a first beam profiler capable of receiving a sample laser beam from the first beam sampler;
a second beam sampler disposed downstream of the first beam sampler;
a second beam profiler capable of receiving a sample laser beam from the second beam sampler,
wherein the optical path correction mechanism further includes a second mirror upstream or downstream of the mirror, the second mirror being capable of being tilted with respect to a direction parallel to the plane where the laser beam travels, and
wherein the controller is configured to:
calculate a difference between a position of a beam observed by the first beam profiler and a first reference beam position;
calculate a difference between a position of a beam observed by the second beam profiler and a second reference beam position; and
determine an amount to translate the mirror and an angular amount to tilt the second mirror based on the difference in the first beam profiler and the difference in the second beam profiler.

6. The laser apparatus according to claim 2 , wherein the controller is configured to determine an amount to translate the mirror based on a temperature of the slab optical amplifier.

7. The laser apparatus according to claim 2 , wherein the controller is configured to determine an amount to translate the mirror based on a time elapsed since activation of the slab optical amplifier.

8. An extreme ultraviolet light generation system comprising:
a chamber;
a target supply device capable of supplying a target into the chamber;
the laser apparatus according to claim 1 capable of outputting a pulse laser beam to hit the target in the chamber; and
a collector mirror capable of collecting extreme ultraviolet light radiated from the target hit by the pulse laser beam and turned into plasma.

9. The extreme ultraviolet light generation system according to claim 8 ,
wherein the laser apparatus includes a pre-pulse laser device and a main pulse laser device, and
wherein the main pulse laser device includes the slab optical amplifier and the mirror.

Assignees

• Gigaphoton Inc

Inventors

• Kurosawa Yoshiaki

Classifications

• H05G2/0086 Primary

  Optical arrangements for conveying the laser beam to the plasma generation location · CPC title

• H01S3/1003

  tunable optical elements, e.g. acousto-optic filters, tunable gratings · CPC title

• H01S3/034

  Optical devices within, or forming part of, the tube, e.g. windows, mirrors (reflectors having variable properties or positions for initial adjustment of the resonator H01S3/086) · CPC title

• H01S3/0071

  Beam steering, e.g. whereby a mirror outside the cavity is present to change the beam direction · CPC title

• H01S3/2325

  Multi-pass amplifiers, e.g. regenerative amplifiers · CPC title