We study the efficiency of coherent anti-Stokes Raman scattering (CARS) under frequency comb excitation. We calculate the power density of the anti-Stokes signal for two major cases: (1) molecular excitation by frequency comb and cw probe and, (2) both excitation and probing by frequency combs. In the first case, average CARS power varies as an inverse third degree of frequency combs free spectral range (FSR); in the second case, it varies as FSR.
View Article and Find Full Text PDFThrough-focus scanning optical microscopy (TSOM) method based on use of a library, which is composed of simulated defocused images of nanosized silicon lines on the top of a monocrystalline silicon substrate, is demonstrated. The images are simulated using Finite-Differences in Time-Domain (FDTD) method taking into account optical aberrations of the experimental setup, which are measured experimentally. Consideration of the optical aberrations allows us to reduce the discrepancy between experimental and simulated defocused images of the samples under study to the value of ≈2%in contrast to ≈10% when the aberrations are not taken into account.
View Article and Find Full Text PDFWe present a novel all optical method for nanoscale pattern inspection. This method uses the chromatic aberration in an imaging optical system and a tunable light source. Such an approach allows stable and precise inspection of nanoscale objects based on an analysis of their defocused diffraction patterns without any external mechanical influence on the sample or optical system.
View Article and Find Full Text PDFA large-scale, double-stream gas puff target has been illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System) to produce high-energy pulses of soft X rays from hot, dense plasma. The double-puff arrangement ensures high gas density and conversion efficiency from NIR to X rays approaching that typical for solid targets. In addition, its major advantage over solid targets is that it is free of debris and has substantially suppressed charged-particle emission.
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