Abstract: In a laser system according to a viewpoint of the present disclosure, a first amplifier amplifies first pulsed laser light outputted from a first semiconductor laser system into second pulsed laser light, a wavelength conversion system converts the second pulsed laser light in terms of wavelength into third pulsed laser light, and an excimer amplifier amplifies the third pulsed laser light. The first semiconductor laser system includes a first current controller that controls current flowing through a first semiconductor laser in such a way that first laser light outputted from the first semiconductor laser is caused to undergo chirping and a first semiconductor optical amplifier that amplifies the first laser light into pulsed light. The laser system includes a control section that controls the amount of chirping performed on the first pulsed laser light in such a way that excimer laser light having a target spectral linewidth is achieved.

Abstract: A laser system includes A. a laser apparatus configured to output pulsed laser light; B. a rare gas chamber; C. a light focusing optical system configured to focus the pulsed laser light in the rare gas chamber to excite the rare gas; D. a filter chamber configured to selectively transmit EUV light contained in harmonic light produced in the rare gas chamber; E. an exhauster connected to the filter chamber; F. at least one through hole disposed in the optical path between the rare gas chamber and the filter chamber; G. a rare gas supplier; H. a flow rate control valve configured to control the flow rate of the rare gas flowing from the rare gas supplier into the rare gas chamber; I. a first pressure sensor configured to detect the pressure of the rare gas in the rare gas chamber; J. a first controller configured to control the flow rate control valve in such a way that the pressure detected with the first pressure sensor falls within a reference range; and K.

Abstract: A wavelength conversion system according to an aspect of the present disclosure includes a first crystal holder holding a first non-linear crystal, a second crystal holder holding a second non-linear crystal, a third crystal holder holding a third non-linear crystal, and a container housing the holders. The container has an entrance window and an emission window. The first non-linear crystal, the second non-linear crystal, and the third non-linear crystal are disposed in this order on an optical path of a laser beam traveling from the entrance window to the emission window. The crystal holders are rotatable. A first rotational axis that is a rotational axis of the first crystal holder is orthogonal to a second rotational axis that is a rotational axis of the second crystal holder, and the first rotational axis is parallel to a third rotational axis that is a rotational axis of the third crystal holder.

Abstract: A laser apparatus according to an aspect of the present disclosure includes a plurality of semiconductor lasers, a plurality of optical switches disposed in the optical paths of the plurality of respective semiconductor lasers, a wavelength conversion system configured to convert pulsed beams outputted from the plurality of optical switches in terms of wavelength to generate wavelength-converted beams, an ArF excimer laser amplifier configured to amplify the wavelength-converted beams, and a controller configured to control the operations of the plurality of semiconductor lasers and the plurality of optical switches, and the plurality of semiconductor lasers are each configured to output a laser beam so produced that wavelengths of the wavelength-converted beams are wavelengths at which the ArF excimer laser amplifier performs amplification and differ from the optical absorption lines of oxygen.

Abstract: A wavelength conversion system including: A. a first nonlinear optical crystal to which first pulsed laser light having a first polarization state and a first wavelength and second pulsed laser light having a second polarization state and a second wavelength are inputted and which is configured to output in response to the input the second pulsed laser light and first sum frequency light having the second polarization state and a third wavelength produced by sum frequency mixing of the first wavelength with the second wavelength; and B. a second nonlinear optical crystal to which the first sum frequency light and the second pulsed laser light outputted from the first nonlinear optical crystal are inputted and which is configured to output in response to the input third pulsed laser light having a fourth wavelength.

Abstract: In a laser system according to a viewpoint of the present disclosure, a first amplifier amplifies first pulsed laser light outputted from a first semiconductor laser system into second pulsed laser light, a wavelength conversion system converts the second pulsed laser light in terms of wavelength into third pulsed laser light, and an excimer amplifier amplifies the third pulsed laser light. The first semiconductor laser system includes a first current controller that controls current flowing through a first semiconductor laser in such a way that first laser light outputted from the first semiconductor laser is caused to undergo chirping and a first semiconductor optical amplifier that amplifies the first laser light into pulsed light. The laser system includes a control section that controls the amount of chirping performed on the first pulsed laser light in such a way that excimer laser light having a target spectral linewidth is achieved.

Abstract: A wavelength conversion system including: A. a first nonlinear optical crystal to which first pulsed laser light having a first polarization state and a first wavelength and second pulsed laser light having a second polarization state and a second wavelength are inputted and which is configured to output in response to the input the second pulsed laser light and first sum frequency light having the second polarization state and a third wavelength produced by sum frequency mixing of the first wavelength with the second wavelength; and B. a second nonlinear optical crystal to which the first sum frequency light and the second pulsed laser light outputted from the first nonlinear optical crystal are inputted and which is configured to output in response to the input third pulsed laser light having a fourth wavelength.

Abstract: A laser system includes A. a laser apparatus configured to output pulsed laser light; B. a rare gas chamber; C. a light focusing optical system configured to focus the pulsed laser light in the rare gas chamber to excite the rare gas; D. a filter chamber configured to selectively transmit EUV light contained in harmonic light produced in the rare gas chamber; E. an exhauster connected to the filter chamber; F. at least one through hole disposed in the optical path between the rare gas chamber and the filter chamber; G. a rare gas supplier; H. a flow rate control valve configured to control the flow rate of the rare gas flowing from the rare gas supplier into the rare gas chamber; I. a first pressure sensor configured to detect the pressure of the rare gas in the rare gas chamber; J. a first controller configured to control the flow rate control valve in such a way that the pressure detected with the first pressure sensor falls within a reference range; and K.

Abstract: An amplifier may include a chamber, and first and second mirrors. The chamber may include a pair of discharge electrodes opposed to each other in a first direction, a laser exciting medium, an input window allowing seed light to pass therethrough into the chamber, and an output window allowing amplified laser light to pass therethrough to outside in a second direction intersecting with the first direction. The first and second mirrors may each include a reflection region, and be opposed to each other in a third direction intersecting with the first direction with the pair of discharge electrodes in between. A projected image of the reflection region of the first mirror in the second direction and a projected image of the reflection region of the second mirror in the second direction may provide a gap of a size equal to or greater than zero in between.