A system for resonantly enhanced frequency conversion includes a nonlinear crystal for frequency converting a pump laser beam, and mirrors forming a ring resonator for the pump laser beam such that a closed propagation path of the pump laser beam, inside the ring resonator, passes through the nonlinear crystal. The mirrors include an adaptive mirror, a curved-mirror pair positioned in a first segment of the propagation path spanning between the adaptive mirror and the nonlinear crystal, and an input coupler for coupling the pump laser beam into the ring resonator. The curved-mirror pair forms an imaging system having conjugate planes at the adaptive mirror and the nonlinear crystal. The input coupler is positioned in a second segment of the propagation path that spans between the adaptive mirror and the nonlinear crystal and does not include deflection by the curved-mirror pair.

A catadioptric projection lens images a pattern of a mask in an effective object field of the projection lens into an effective image field of the projection lens with electromagnetic radiation with an operating wavelength λ<260 nm. The projection lens includes a multiplicity of lens elements and a multiplicity of mirrors including at least one concave mirror. The lens elements and mirrors define a projection beam path that extends from the object plane to the image plane and contains at least one pupil plane. The mirrors include a first mirror having a first mirror surface in the projection beam path between the object and pupil planes in the optical vicinity of a first field plane optically conjugate to the object plane. The mirrors also include a second mirror having a second mirror surface in the projection beam path between the pupil and image planes in the optical vicinity of a second field plane that is optically conjugate to the first field plane. The first mirror surface and/or the second mirror surface is a freeform surface.

An optical system for a lithography apparatus includes an optical element. The optical element comprises a substrate, an optically effective area provided on the substrate, and a plurality of channels which run through the substrate and to which a pressure can be applied via a fluid. An initial surface profile and a target surface profile different from the initial surface profile are associated with the optically effective area. The optically effective area can be switched from the initial surface profile to the target surface profile by applying pressure and a resulting deformation of the channels.

A system for resonantly enhanced frequency conversion includes a nonlinear crystal for frequency converting a pump laser beam, and mirrors forming a ring resonator for the pump laser beam such that a closed propagation path of the pump laser beam, inside the ring resonator, passes through the nonlinear crystal. The mirrors include an adaptive mirror, a curved-mirror pair positioned in a first segment of the propagation path spanning between the adaptive mirror and the nonlinear crystal, and an input coupler for coupling the pump laser beam into the ring resonator. The curved-mirror pair forms an imaging system having conjugate planes at the adaptive mirror and the nonlinear crystal. The input coupler is positioned in a second segment of the propagation path that spans between the adaptive mirror and the nonlinear crystal and does not include deflection by the curved-mirror pair.

Optical system includes front group, light-shielding member, and rear group that are arranged in direction from object side toward image side. The light-shielding member is provided with opening elongated in first direction. The front group does not image the object at the opening in first section parallel to the first direction and forms intermediate image of the object at the opening in second section perpendicular to the first direction. The rear group has diffractive surface that splits light beam that passes through the opening into light beams at different wavelengths in the second section and focuses the light beams on different locations in the second section. F-number for the side of the image in the first section differs from an F-number for the side of the image in the second section.

Optical system includes front group, light-shielding member, and rear group that are arranged in this order in direction from object side toward image side. The light-shielding member is provided with opening elongated in first direction. The front group has aspherical surfaces, does not image the object at the opening in first section parallel to the first direction, and forms intermediate image of the object at the opening in second section perpendicular to the first direction. The rear group has diffractive surface that splits light beam that passes through the opening into light beams at different wavelengths in the second section and focuses the light beams on different locations in the second section. Tilt angles of the aspherical surfaces in the second section change in the first direction.

A catadioptric projection lens images a pattern of a mask in an effective object field of the projection lens into an effective image field of the projection lens with electromagnetic radiation with an operating wavelength <260 nm. The projection lens includes a multiplicity of lens elements and a multiplicity of mirrors including at least one concave mirror. The lens elements and mirrors define a projection beam path that extends from the object plane to the image plane and contains at least one pupil plane. The mirrors include a first mirror having a first mirror surface in the projection beam path between the object and pupil planes in the optical vicinity of a first field plane optically conjugate to the object plane. The mirrors also include a second mirror having a second mirror surface in the projection beam path between the pupil and image planes in the optical vicinity of a second field plane that is optically conjugate to the first field plane. The first mirror surface and/or the second mirror surface is a freeform surface.

Optical system includes front group, light-shielding member, and rear group that are arranged in this order in direction from object side toward image side. The light-shielding member is provided with opening elongated in first direction. The front group has aspherical surfaces, does not image the object at the opening in first section parallel to the first direction, and forms intermediate image of the object at the opening in second section perpendicular to the first direction. The rear group has diffractive surface that splits light beam that passes through the opening into light beams at different wavelengths in the second section and focuses the light beams on different locations in the second section. Tilt angles of the aspherical surfaces in the second section change in the first direction.

An image forming optical system 1 includes, in order from an enlargement side, a first optical system 111 having a reflecting surface, and a second optical system 112 having a refracting surface. The image forming optical system 1 is configured to form an intermediate image 104 between the first optical system 111 and the second optical system 112. The first optical system 111 includes, in order from the enlargement side, a first reflecting group 113 having at least one reflecting surface having negative power, and a second reflecting group 114 having a plurality of reflecting surfaces 116 and 117 having positive power. The at least one reflecting surface having negative power includes a reflecting surface 115 closest to the enlargement side in the first reflecting group 113. An absolute value of power of the reflecting surface 115 is smallest in the first optical system 111.

A satellite with deployable optics is provided. The satellite has a frame, an optical axis, and a deployable optical system. The optical system has a mechanical aperture perpendicular to the optical axis, where light collected travels substantially parallel to the optical axis. The optical system has a stored configuration in which it remains within the frame and a deployed configuration in which it extends outside the frame. In some configurations, the light-collecting area of the deployed configuration is larger than the possible light-collecting area of the stored configuration. In a partially deployed configuration, all of the primary mirror segments remain substantially within the frame, and the light-collecting area is smaller than that in the deployed configuration. A method of using the satellite includes setting the satellite to the deployed configuration, detecting whether there is a deployment malfunction, and, if so, setting the satellite to a partially deployed configuration.