Laser apparatus, extreme ultraviolet light generation system, method for controlling the laser apparatus, and method for generating the extreme ultraviolet light

摘要

A laser apparatus may include: a master oscillator configured to output a pulsed laser beam at a repetition rate, the master oscillator including at least one semiconductor laser apparatus; at least one amplifier configured to amplify the pulsed laser beam from the master oscillator, the at least one amplifier being configured to include at least one gain bandwidth; and a controller for controlling a parameter affecting an output wavelength of the pulsed laser beam from the master oscillator such that a wavelength chirping range of the pulsed laser beam from the master oscillator overlaps at least a part of the at least one gain bandwidth.

主权项

1. A laser apparatus, comprising:
a master oscillator configured to output a pulsed laser beam at a repetition rate, each pulse of the pulsed laser beam being chirped, the master oscillator including a plurality of semiconductor laser apparatuses; at least one amplifier configured to amplify the pulsed laser beam from the master oscillator, the at least one amplifier being configured to include a plurality of gain bandwidths; and a controller for controlling a temperature of each of the plurality of semiconductor laser apparatuses, as a parameter affecting an output wavelength of the pulsed laser beam such that a wavelength chirping range of the pulsed laser beam overlaps at least a part of at least one of the plurality of gain bandwidths, wherein:
at least two of the plurality of semiconductor laser apparatuses output pulsed laser beams having wavelength chirping ranges different from each other, the controller controls such that the temperature of each of the plurality of semiconductor laser apparatuses is placed between a first temperature at which a temporally initial wavelength in a single pulse of the pulsed laser beam becomes a longest wavelength of the at least one of the plurality of gain bandwidths and a second temperature at which a temporally final wavelength in a single pulse of the pulsed laser beam becomes a shortest wavelength of the at least one of the plurality of gain bandwidths; and the wavelength chirping range of each pulse of the pulsed laser beam has the temporally initial wavelength, the temporally final wavelength, and a plurality of wavelengths extending from the temporally initial wavelength to the temporally final wavelength, with at least one of the temporally initial wavelength and the temporally final wavelength being outside the at least one of the plurality of gain bandwidths, and at least one of the plurality of wavelengths being inside the at least one of the plurality of gain bandwidths.