Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: An assembly for collimating broadband radiation, the assembly including: a convex refractive singlet lens having a first spherical surface for coupling the broadband radiation into the lens and a second spherical surface for coupling the broadband radiation out of the lens, wherein the first and second spherical surfaces have a common center; and a mount for holding the convex refractive singlet lens at a plurality of contact points having a centroid coinciding with the common center.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: A broadband radiation source device, including a fiber assembly having a plurality of optical fibers, each optical fiber being filled with a gas medium, wherein the broadband radiation source device is operable such that subsets of the optical fibers are independently selectable for receiving a beam of input radiation so as to generate a broadband output from only a subset of the plurality of optical fibers at any one time.

Abstract: An assembly for collimating broadband radiation, the assembly including: a convex refractive singlet lens having a first spherical surface for coupling the broadband radiation into the lens and a second spherical surface for coupling the broadband radiation out of the lens, wherein the first and second spherical surfaces have a common center; and a mount for holding the convex refractive singlet lens at a plurality of contact points having a centroid coinciding with the common center.

Abstract: A broadband radiation source device, including a fiber assembly having a plurality of optical fibers, each optical fiber being filled with a gas medium, wherein the broadband radiation source device is operable such that subsets of the optical fibers are independently selectable for receiving a beam of input radiation so as to generate a broadband output from only a subset of the plurality of optical fibers at any one time.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: A broadband radiation source device, including a fiber assembly having a plurality of optical fibers, each optical fiber being filled with a gas medium, wherein the broadband radiation source device is operable such that subsets of the optical fibers are independently selectable for receiving a beam of input radiation so as to generate a broadband output from only a subset of the plurality of optical fibers at any one time.

Abstract: An assembly for collimating broadband radiation, the assembly including: a convex refractive singlet lens having a first spherical surface for coupling the broadband radiation into the lens and a second spherical surface for coupling the broadband radiation out of the lens, wherein the first and second spherical surfaces have a common center; and a mount for holding the convex refractive singlet lens at a plurality of contact points having a centroid coinciding with the common center.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: A lithographic method for measuring a position of a target grating with a mask sensor apparatus which comprises a plurality of detector modules each comprising a diffraction grating located at a mask side of a projection system of a lithographic apparatus and an associated detector, the method comprising a first step of measuring first intensities of a combination of diffraction orders diffracted from the target grating while the mask sensor apparatus is moved relatively to the target grating along a first direction; a second step of displacing the mask sensor apparatus relative to the target grating in a second direction, wherein a size of the relative displacement is proportional to a spatial frequency of a potential error; and a third step of measuring second intensities of the combination of diffraction orders diffracted from the target grating while the mask sensor apparatus is moved relatively to the target grating along the first direction.

Abstract: A lithographic method for measuring a position of a target grating with a mask sensor apparatus which comprises a plurality of detector modules each comprising a diffraction grating located at a mask side of a projection system of a lithographic apparatus and an associated detector, the method comprising a first step of measuring first intensities of a combination of diffraction orders diffracted from the target grating while the mask sensor apparatus is moved relatively to the target grating along a first direction; a second step of displacing the mask sensor apparatus relative to the target grating in a second direction, wherein a size of the relative displacement is proportional to a spatial frequency of a potential error; and a third step of measuring second intensities of the combination of diffraction orders diffracted from the target grating while the mask sensor apparatus is moved relatively to the target grating along the first direction.