A light source for high power coherent light can include multiparticle relativistic bunches of electrons generating high intensity propagating fields. Coherent emission between electrons may also be utilized. The source may be independent of any medium or media to remove all constraints on the wavelength of the light emitted. And at least a portion of a single alternating magnetic field for accelerating the electron bunches can be included. The color or wavelength of the produced light can be determined solely by the parameters of the electron bunches and the alternating field. The source can be used for imaging, such as medical imaging or for security, including concealed weapons, and for quality control.

Orbital debt is removal (ODR) systems under the present approach may use a ground- or surface-based FEL and mirror system with sufficient power and both spatial and temporal resolution to both locate Category II OD (1 cm to 10 cm diameter) in low Earth orbit (LEO, 160 to 2000 km altitude) and remove these objects from orbit. Locating the Category II OD is performed by having, the light beam from an FEL and its beam director scan a volume of space of interest and then observing the light reflected from the OD. Removing the OD may include heating the OD to a sufficiently high temperature to evaporate the OD, changing the orbit of the OD such as to lower the perigee, or both. Megawatt-class MOPA FELs for, inter alia, removing OD, are described.

A dielectric-grating waveguide free-electron laser device generating coherent or laser-like radiation is provided. An electron beam propagates next to a dielectric waveguide with a built-in grating structure to generate highly confined coherent or laser-like radiation in the waveguide through the Bragg resonance, the backward-wave resonance, or the Fabry-Perot resonance provided by the grating-waveguide structure. The dielectric-grating waveguide can be made of linear optical materials or nonlinear optical materials or combination of linear and nonlinear optical materials to enable versatile functionalities, such as laser generation, laser-wavelength conversion, and laser signal processing. Owing to the build-up of the laser modes inside the dielectric waveguide, coherent or laser-like Smith-Purcell radiation is also generated above the grating via coupling and bunching of the electrons with the surface mode fields.

A light source for high power coherent light can include multiparticle relativistic bunches of electrons generating high intensity propagating fields. Coherent emission between electrons may also be utilized. The source may be independent of any medium or media to remove all constraints on the wavelength of the light emitted. And at least a portion of a single alternating magnetic field for accelerating the electron bunches can be included. The color or wavelength of the produced light can be determined solely by the parameters of the electron bunches and the alternating field. The source can be used for imaging, such as medical imaging or for security, including concealed weapons, and for quality control.

Superconducting undulators (SCUs) require thermal control of large heat loads for proper operation and to provide high radiation output powers. A conduction cooling apparatus for an SCU device includes a beam chamber having a hollow core inside of the beam chamber along a length of the beam chamber. The hollow core allows charged particles to pass through the hollow core of the beam chamber to generate output radiation. A beam chamber holder is physically and thermally coupled to the beam chamber to maintain a position, and control a temperature of, the beam chamber. At least one magnet is configured to provide a magnetic field to the hollow core, and at least one cooling bar is physically and thermally coupled to the magnet. A cooling source is thermally coupled to both the beam chamber holder and the cooling bar to provide cooling capacity to the beam chamber and the magnet.

An illumination system for an EUV projection lithographic projection exposure apparatus comprises an EUV light source, which generates an output beam of EUV illumination light with a predetermined polarization state. An illumination optical unit guides the output beam along an optical axis, as a result of which an illumination field in a reticle plane is illuminated by the output beam. The light source comprises an electron beam supply device, an EUV generating device and a polarization setting device. The EUV generating device is supplied with an electron beam by the electron beam supply device. The polarization setting device exerts an adjustable deflecting effect on the electron beam for setting the polarization of the output beam. This results in an illumination system, which operates on the basis of an electron beam-based EUV light source and provides an output beam, which is improved for a resolution-optimized illumination.

At least one method, apparatus and system for providing capturing synchrotron radiation for a metrology tool, are disclosed. A beam using a first light emitting device is provided. The first light emitting device comprises a first electron path bend. A first synchrotron radiation is provided from the first electron path bend to a first metrology tool configured to perform a metrology inspection using the first synchrotron radiation.

The invention relates to a method for generating electromagnetic radiation (preferably UV, VUV, XUV, or X-rays), to an optical short-period undulator (10) and to a free-electron laser comprising the latter. To accomplish the method, a high-energy electrically charged particle beam (5) is provided, and high-intensity electromagnetic pulses (7, 7a, 7b) are generated, and by interfering said pulses with one another an electromagnetic standing wave is created, wherein said standing wave has an electric field strength of a pre-determined peak value. The particle beam is directed through the non-steady electromagnetic field of the standing wave in or in the vicinity of a plane spanned by nodes with maximal electric field strength of said electromagnetic standing wave. Meanwhile, by the electromagnetic field of the standing wave, the particle beam is forced to travel along an undulating path and thereby, in the form of radiation emitted by said particle beam, electromagnetic radiation that propagates in the propagation direction of the particle beam is generated. Said short-period undulator (10) comprises a pulse source (2) to emit high-intensity pulses falling into the terahertz frequency range and an interaction region to direct a high-energy electrically charged particle beam, in particular an electron beam, through the undulator with undulator effect. The undulator effect is provided in the interaction region through a dynamic effect developing in or in the vicinity of a plane spanned by nodes with maximal electric field strength of an electromagnetic standing wave created by the interference of high-intensity pulses falling into the terahertz frequency range, emitted by said pulse source.

A method of patterning lithographic substrates that includes using a free electron laser to generate EUV radiation and delivering the EUV radiation to a lithographic apparatus which projects the EUV radiation onto lithographic substrates. The method further includes reducing fluctuations in the power of EUV radiation delivered to the lithographic substrates by using a feedback-based control loop to monitor the free electron laser and adjust operation of the free electron laser accordingly, and applying variable attenuation to EUV radiation that has been output by the free electron laser in order to further control the power of EUV radiation delivered to the lithographic apparatus.

Passage through LINACs of electron bunches in their acceleration phase is coordinated with passage through the LINACs of electron bunches in their deceleration phase. Each successive pair of electron bunches are spaced in time by a respective bunch spacing, in accordance with a repeating electron bunch sequence. The electron source provides clearing gaps in the electron bunch sequence to allow clearing of ions at the undulator. The electron source provides the clearing gaps in accordance with a clearing gap sequence such that, for each of the plurality of energy recovery LINACS, and for substantially all of the clearing gaps: for each passage of the clearing gap through the LINAC in an acceleration phase or deceleration phase the clearing gap is coordinated with a further one of the clearing gaps passing through the LINAC in a deceleration phase or acceleration phase thereby to maintain energy recovery operation of the LINAC.