An optical system for directing first and second laser pulses along an optical axis to a target to generate extreme ultraviolet radiation from said target. The optical system comprises a first optical component configured to redistribute a first laser pulse to form a shaped laser pulse having a hollow region. The optical system comprise a second optical component configured to focus the shaped laser pulse toward the target. The optical system comprises a third optical component configured to focus a second laser pulse toward the target within the hollow region of the shaped laser pulse. The first, second and third optical components are coaxially arranged on the optical axis.

A method for generating isolated ultra-short electromagnetic pulses, includes the following steps: directing onto a surface of a target in the condensed state a first laser pulse at an oblique angle of incidence and with p-polarization, the first laser pulse having a normalized peak amplitude greater than or equal to 1, whereby a plasma mirror oscillating at relativistic velocity is generated on the surface of the target; and directing onto the surface of the target, in correspondence with the plasma mirror, a second laser pulse of duration shorter than or equal to the optical period of the first pulse, the second laser pulse being spatially and temporally superposed with the first laser pulse; whereby the second laser pulse, reflected by the plasma mirror, undergoes a shift of its wavelength and a modification of its duration.

An optical assembly includes a bulb and a lens for a laser-operated light source. The bulb has a chamber for accommodating an ionizable gas and a plasma formed by energizing the ionizable gas and has a longitudinal axis and a transverse axis perpendicular to the longitudinal axis. In use, the lens is arranged to focus a wavefront of radiation from a laser to a virtual object point located inside the chamber. In use, the bulb is arranged to transmit and refract the wavefront of the radiation to a first real image point in a first cross-section of the longitudinal axis and a second real image point in a second cross-section of the transverse axis. The first real image point and the second real image point are image conjugates of the virtual object point. The virtual object point, the first real image point and the second real image point coincide.

A light source system, preferably including one or more electron inputs, splitters, recombiners, and/or electron outputs, and optionally including one or more accelerator modules, input transports, radiator modules, and/or output transports. The system can optionally include one or more ancillary elements (e.g., electron optics elements). A method of operation, preferably including operating in a normal mode and/or operating in a backup mode.

A light source system, preferably including one or more electron inputs, splitters, recombiners, and/or electron outputs, and optionally including one or more accelerator modules, input transports, radiator modules, and/or output transports. The system can optionally include one or more ancillary elements (e.g., electron optics elements). A method of operation, preferably including operating in a normal mode and/or operating in a backup mode.

A device for generating extreme ultraviolet (EUV) radiation includes an optical beam-forming arrangement with a focusing unit for forming a laser beam, and a target material configured to be irradiated with the laser beam to emit EUV radiation. The beam-forming arrangement includes a beam rotator for image field rotation of the laser beam.

A light source system, preferably including one or more electron inputs, splitters, recombiners, and/or electron outputs, and optionally including one or more accelerator modules, input transports, radiator modules, and/or output transports. The system can optionally include one or more ancillary elements (e.g., electron optics elements). A method of operation, preferably including operating in a normal mode and/or operating in a backup mode.

An EUV light generation system includes a processor controlling an actuator which changes an irradiation position of laser light on a target. The processor executes a first control of acquiring a value of a first index related to output values of EUV energy sensors, acquiring a value of a second index related to a ratio of the output values of the EUV energy sensors, and controlling the actuator based on the value of the first index; and a second control of, during the first control, controlling the actuator to move the irradiation position of the laser light in a direction for causing the value of the second index not to exceed a vibration threshold when the value of the second index has exceeded the vibration threshold which reflects a vibration occurrence irradiation position being the irradiation position at which the EUV energy temporally vibrates due to the buffer gas.

A system includes a chamber, a laser beam apparatus configured to generate a laser beam to be introduced into the chamber, a laser controller for the laser beam apparatus to control at least a beam intensity and an output timing of the laser beam, and a target supply unit configured to supply a target material into the chamber, the target material being irradiated with the laser beam for generating extreme ultraviolet light.

An EUV light source includes a rotatable, cylindrically-symmetric element having a surface coated with a plasma-forming target material, a drive laser source configured to generate one or more laser pulses sufficient to generate EUV light via formation of a plasma by excitation of the plasma-forming target material, a set of focusing optics configured to focus the one or more laser pulses onto the surface of the rotatable, cylindrically-symmetric element, a set of collection optics configured to receive EUV light emanated from the generated plasma and further configured to direct the illumination to an intermediate focal point, and a gas management system including a gas supply subsystem configured to supply plasma-forming target material to the surface of the rotatable, cylindrically-symmetric element.