Abstract: The laser system may include first and second laser apparatuses and a beam delivery device. The first laser apparatus may be provided so as to emit a first laser beam to the beam delivery device in a first direction. The second laser apparatus may be provided so as to emit a second laser beam to the beam delivery device in a direction substantially parallel to the first direction. The beam delivery device may be configured to bundle the first and second laser beams and to emit the first and second laser beams from the beam delivery device to a beam delivery direction different from the first direction.

Abstract: The laser system may include first and second laser apparatuses and a beam delivery device. The first laser apparatus may be provided so as to emit a first laser beam to the beam delivery device in a first direction. The second laser apparatus may be provided so as to emit a second laser beam to the beam delivery device in a direction substantially parallel to the first direction. The beam delivery device may be configured to bundle the first and second laser beams and to emit the first and second laser beams from the beam delivery device to a beam delivery direction different from the first direction.

Abstract: An apparatus for generating extreme ultraviolet light may include a reference member, a chamber fixed to the reference member, the chamber including at least one window, a laser beam introduction optical system configured to introduce an externally supplied laser beam into the chamber through the at least one window, and a positioning mechanism configured to position the laser beam introduction optical system to the reference member.

Abstract: An apparatus for generating extreme ultraviolet light may include a reference member, a chamber fixed to the reference member, the chamber including at least one window, a laser beam introduction optical system configured to introduce an externally supplied laser beam into the chamber through the at least one window, and a positioning mechanism configured to position the laser beam introduction optical system to the reference member.

Abstract: A chamber apparatus, which may be used with an external apparatus having an obscuration region, may include: a chamber in which EUV light is generated; a collector mirror having a first through-hole formed in a region aside from the center thereof and configured to collect the EUV light generated inside the chamber, the collector mirror being positioned such that the first through-hole is located in a region substantially corresponding to the obscuration region; and an etching gas supply unit provided in the first through-hole and configured to supply an etching gas into the chamber.

Abstract: A holder device for holding an optical element includes a holder having first and second members to sandwich the optical element therebetween, and a sealing member for creating a seal between the second member and the optical element.

Abstract: A holder device for holding an optical element includes a holder having first and second members to sandwich the optical element therebetween, and a sealing member for creating a seal between the second member and the optical element.

Abstract: A chamber apparatus, which may be used with an external apparatus having an obscuration region, may include: a chamber in which EUV light is generated; a collector mirror having a first through-hole formed in a region aside from the center thereof and configured to collect the EUV light generated inside the chamber, the collector mirror being positioned such that the first through-hole is located in a region substantially corresponding to the obscuration region; and an etching gas supply unit provided in the first through-hole and configured to supply an etching gas into the chamber.