Abstract: Apparatus and methods for complex imaging reflectometry and refractometry using at least partially coherent light. Quantitative images yield spatially-dependent, local material information about a sample of interest. These images may provide material properties such as chemical composition, the thickness of chemical layers, dopant concentrations, mixing between layers of a sample, reactions at interfaces, etc. An incident beam of VUV wavelength or shorter is scattered off of a sample and imaged at various angles, wavelengths, and/or polarizations. The power of beam is also measured. This data is used to obtain images of a sample's absolute, spatially varying, complex reflectance or transmittance, which is then used to determine spatially-resolved, depth-dependent sample material properties.

Abstract: Apparatus and methods for improved HHG of ultrashort pulse laser beams. A HHG assembly includes a gas distribution block and a waveguide cartridge having a HHG hollow core waveguide. The waveguide cartridge is attached to the gas distribution block and may be removed and replaced, while the gas distribution block remains affixed within the apparatus. The gas distribution block is configured to maintain a pressure profile within the hollow core fiber. The system also includes two operating beam sensors and two actuatable mirrors. The operating beam sensors are fixed with respect to the HHG assembly. The system is aligned before operation by adjusting the actuatable mirrors to optimize a sample beam through the waveguide and recording the position of the beam on the operating beam sensors. In operation, the mirrors are actuated to maintain the same positions of the input beam on the operating beam sensors.

Abstract: Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the “standard data set”) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the “modulus enforced probe (MEP) dataset”. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.

Abstract: Apparatus and methods for improved HHG of ultrashort pulse laser beams. A HHG assembly includes a gas distribution block and a waveguide cartridge having a HHG hollow core waveguide. The waveguide cartridge is attached to the gas distribution block and may be removed and replaced, while the gas distribution block remains affixed within the apparatus. The gas distribution block is configured to maintain a pressure profile within the hollow core fiber. The system also includes two operating beam sensors and two actuatable mirrors. The operating beam sensors are fixed with respect to the HHG assembly. The system is aligned before operation by adjusting the actuatable mirrors to optimize a sample beam through the waveguide and recording the position of the beam on the operating beam sensors. In operation, the mirrors are actuated to maintain the same positions of the input beam on the operating beam sensors.

Abstract: Apparatus and methods for coherent diffraction imaging This is accomplished by acquiring data in a CDI setup with a CMOS or similar detector. The object is illuminated with coherent light such as EUV light which may be pulsed. This generates diffraction patterns which are collected by the detector, either in frames or continuously (by recording the scan position during collection). Pixels in the CDI data are thresholded and set to zero photons if the pixel is below the threshold level. Pixels above the threshold may be set to a value indicating one photon, or multiple thresholds may be used to set pixels values to one photon, two photons, etc. In addition, multiple threshold values may be used to detect different photon energies for illumination at multiple wavelengths.

Abstract: Apparatus and methods for generating controllable, narrow-band radiation at short wavelengths, driven by two colors injected into a structured waveguide. The use of multicolor excitation with the structured waveguide allows the use of very small guided beam diameters, without damaging the waveguide. Reduced guided wave mode area combined with low intensities required to drive wave-mixing frequency conversion allow the use of very compact, high average power, moderate peak intensity femtosecond fiber laser technology to drive useful conversion efficiency of laser light into the deep-UV and vacuum-UV at MHz repetition rates.

Abstract: Apparatus and methods for complex imaging reflectometry and refractometry using at least partially coherent light. Quantitative images yield spatially-dependent, local material information about a sample of interest. These images may provide material properties such as chemical composition, the thickness of chemical layers, dopant concentrations, mixing between layers of a sample, reactions at interfaces, etc. An incident beam of VUV wavelength or shorter is scattered off of a sample and imaged at various angles, wavelengths, and/or polarizations. The power of beam is also measured. This data is used to obtain images of a sample's absolute, spatially varying, complex reflectance or transmittance, which is then used to determine spatially-resolved, depth-dependent sample material properties.

Abstract: Apparatus and methods of full spatio-temporal characterization of ultrashort pulses from an input pulse-beam source. An interferometer system generates a first, second, third, and fourth replica of the input pulse-beam such that the second replica has a varying delay with respect to the first replica and the fourth replica has a varying delay with respect to the third replica. A reference plane is imaged onto a nonlinear spectral measurement device based upon the first and second replicas, and the reference plane is also imaged onto a wavefront sensitive (WFS) imaging element based on the third and fourth replicas. The signals from the WFS imaging element and the spectral signal are used to compute a pulse temporal spectral profile of the input pulse-beam.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: Apparatus and methods for generating controllable, narrow-band radiation at short wavelengths, driven by two colors injected into a structured waveguide. The use of multicolor excitation with the structured waveguide allows the use of very small guided beam diameters, without damaging the waveguide. Reduced guided wave mode area combined with low intensities required to drive wave-mixing frequency conversion allow the use of very compact, high average power, moderate peak intensity femtosecond fiber laser technology to drive useful conversion efficiency of laser light into the deep-UV and vacuum-UV at MHz repetition rates.

Abstract: Apparatus and methods of full spatio-temporal characterization of ultrashort pulses from an input pulse-beam source. An interferometer system generates a first, second, third, and fourth replica of the input pulse-beam such that the second replica has a varying delay with respect to the first replica and the fourth replica has a varying delay with respect to the third replica. A reference plane is imaged onto a nonlinear spectral measurement device based upon the first and second replicas, and the reference plane is also imaged onto a wavefront sensitive (WFS) imaging element based on the third and fourth replicas. The signals from the WFS imaging element and the spectral signal are used to compute a pulse temporal spectral profile of the input pulse-beam.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: Apparatus and methods for complex imaging reflectometry and refractometry using at least partially coherent light (121). Quantitative images yield spatially-dependent, local material information about a sample (128, 228) of interest. These images may provide material properties such as chemical composition, the thickness of chemical layers, dopant concentrations, mixing between layers of a sample, reactions at interfaces, etc. An incident beam (123) of VUV wavelength or shorter is scattered off of a sample (128, 228) and imaged at various angles, wavelengths, and/or polarizations. The power of beam (123) is also measured. This data is used to obtain images of a sample's absolute, spatially varying, complex reflectance or transmittance, which is then used to determine spatially-resolved, depth-dependent sample material properties.

Abstract: Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the “standard data set”) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the “modulus enforced probe (MEP) dataset”. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: Apparatus and methods for Coherent Diffractive Imaging with multiple, simultaneous, spatially distinct beams chosen and configured to isolate incoherent sums of beam diffraction such that interference between the multiple beams is not present in the data prior to computationally reconstructing the image. This is accomplished through selecting the multiple beams to be non-interfering modes, or through designing the apparatus such that the interference is not recorded, or through processing the collected data to filter the interference before reconstructing the image.

Abstract: Apparatus and methods for coherent diffractive imaging with arbitrary angle of illumination incidence utilize a method of fast remapping of a detected diffraction intensity pattern from a detector pixel array (initial grid) to a uniform spatial frequency grid (final grid) chosen to allow for FFT on the remapped pattern. This is accomplished by remapping the initial grid to an intermediate grid chosen to result in a final grid that is linear in spatial frequency. The initial grid is remapped (generally by interpolation) to the intermediate grid that is calculated to correspond to the final grid. In general, the initial grid (x,y) is uniform in space, the intermediate grid ({tilde over (x)},{tilde over (y)}) is non-uniform in spatial frequency, and the final grid ({tilde over (f)}x,{tilde over (f)}y) is uniform in spatial frequency.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: Apparatus and methods for Coherent Diffractive Imaging with multiple, simultaneous, spatially distinct beams chosen and configured to isolate incoherent sums of beam diffraction such that interference between the multiple beams is not present in the data prior to computationally reconstructing the image. This is accomplished through selecting the multiple beams to be non-interfering modes, or through designing the apparatus such that the interference is not recorded, or through processing the collected data to filter the interference before reconstructing the image.