Extreme ultraviolet light generation device and focused beam measurement device of pulsed laser light

摘要

Provided is an extreme ultraviolet light generating apparatus that may include: a chamber containing one or more kinds of gases; a light concentration optical system provided in an optical path of pulsed laser light outputted from a laser unit, and configured to concentrate the pulsed laser light into a concentrated beam; and an image pickup section provided at a position out of the optical path of the pulsed laser light, and configured to pick up a plasma emission image that is an image of plasma emission in the chamber. The plasma emission is caused by application of the concentrated beam to the one or more kinds of gases in the chamber.