Patent ID: 11924954
Assignee: GIGAPHOTON INC.
Field: Medical technology (Instruments)
Classification: CPC H  G | IPC G  H

Claim 10:
11. An extreme ultraviolet light generation apparatus comprising:
a chamber;
a target supply unit configured to supply a target to a plasma generation region in the chamber;
a laser system configured to emit first laser light having a polarization direction deflected in one direction and second laser light to generate a secondary target that is the target diffused by irradiating the target with the first laser light from a direction perpendicular to a travel axis of the target and to generate extreme ultraviolet light by irradiating the secondary target with the second laser light;
a polarization direction adjustment unit arranged on an optical path of the first laser light and configured to adjust the polarization direction of the first laser light;
an extreme ultraviolet light observation unit configured to observe energy of the extreme ultraviolet light; and
a processor configured to control the polarization direction adjustment unit based on an observation result of the extreme ultraviolet light observation unit,
wherein a linear polarization degree P of the first laser light defined as P={(Imax−Imin)/(Imax+Imin)}×100(%) is 90% or more, where Imax and Imin represent a maximum value and a minimum value, respectively, of light intensity obtained by causing laser light to be incident on a polarization prism and measuring the light intensity of emission light from the polarization prism with a rotation angle thereof changed by rotating the polarization prism about an optical path axis of the laser light.