16,032 research outputs found

    Three Dimensional Imaging of the Nucleon

    Full text link
    We study the Wigner distributions of quarks and gluons in light-front dressed quark model using the overlap of light front wave functions (LFWFs). We take the target to be a dressed quark, this is a composite spin 1/2-1/2 state of quark dressed with a gluon. This state allows us to calculate the quark and gluon Wigner distributions analytically in terms of LFWFs using Hamiltonian perturbation theory. We analyze numerically the Wigner distributions of quark and gluon and report their nature in the contour plots. We use an improved numerical technique to remove the cutoff dependence of the Fourier transformed integral over Δ{\bf \Delta}_\perp.Comment: 7 pages, 2 figures, Prepared for Proceedings of Light Cone 2017, 18-22 Sept, University of Mumbai, India. To appear in FB

    Three dimensional imaging of short pulses

    Full text link
    We exploit a slightly noncollinear second-harmonic cross-correlation scheme to map the 3D space-time intensity distribution of an unknown complex-shaped ultrashort optical pulse. We show the capability of the technique to reconstruct both the amplitude and the phase of the field through the coherence of the nonlinear interaction down to a resolution of 10 μ\mum in space and 200 fs in time. This implies that the concept of second-harmonic holography can be employed down to the sub-ps time scale, and used to discuss the features of the technique in terms of the reconstructed fields.Comment: 16 pages, 6 figure

    Three-dimensional imaging of random radiation sources

    Get PDF
    A method to image random three-dimensional source distributions is proposed. We show that, by using a Michelson stellar interferometer in a prescribed fashion, one is able to measure a special form of a three-dimensional degree of coherence. The inverse Fourier transform of this coherence function yields the three-dimensional intensity distribution of the source as seen from the paraxial far zone

    Three-dimensional Imaging of Microstructure in Gold Nanocrystals

    Get PDF
    X-ray diffraction using a coherent beam involves the mutual interference among all the extremities of small crystals. The continuous diffraction pattern so produced can be phased because it can be oversampled. We have thus obtained three-dimensional images of the interiors of Au nanocrystals that show 50 nm wide bands of contrast with f111g orientation that probably arise from internal twinning by dynamic recrystallization during their formation at high temperature

    Three-dimensional imaging of direct-written photonic structures

    Full text link
    Third harmonic generation microscopy has been used to analyze the morphology of photonic structures created using the femtosecond laser direct-write technique. Three dimensional waveguide arrays and waveguide-Bragg gratings written in fused-silica and doped phosphate glass were investigated. A sensorless adaptive optical system was used to correct the optical aberrations occurring in the sample and microscope system, which had a lateral resolution of less than 500 nm. This non-destructive testing method creates volume reconstructions of photonic devices and reveals details invisible to other linear microscopy and index profilometry techniques.Comment: 8 pages, 3 color figures, 2 hyper-linked animation

    Single shot three-dimensional imaging of dilute atomic clouds

    Get PDF
    Light field microscopy methods together with three dimensional (3D) deconvolution can be used to obtain single shot 3D images of atomic clouds. We demonstrate the method using a test setup which extracts three dimensional images from a fluorescent 87^{87}Rb atomic vapor.Comment: 10 pages, 5 figure

    Measuring every particle's size from three-dimensional imaging experiments

    Full text link
    Often experimentalists study colloidal suspensions that are nominally monodisperse. In reality these samples have a polydispersity of 4-10%. At the level of an individual particle, the consequences of this polydispersity are unknown as it is difficult to measure an individual particle size from microscopy. We propose a general method to estimate individual particle radii within a moderately concentrated colloidal suspension observed with confocal microscopy. We confirm the validity of our method by numerical simulations of four major systems: random close packing, colloidal gels, nominally monodisperse dense samples, and nominally binary dense samples. We then apply our method to experimental data, and demonstrate the utility of this method with results from four case studies. In the first, we demonstrate that we can recover the full particle size distribution {\it in situ}. In the second, we show that accounting for particle size leads to more accurate structural information in a random close packed sample. In the third, we show that crystal nucleation occurs in locally monodisperse regions. In the fourth, we show that particle mobility in a dense sample is correlated to the local volume fraction.Comment: 7 pages, 5 figure

    General theorem of spatial coherence: application to three-dimensional imaging

    Get PDF
    Three-dimensional imaging of incoherent light sources by the Michelson stellar interferometer is considered. When the interferometer’s pinholes are arranged properly, its output result is equivalent to a two-dimensional Fourier hologram that stores information about the source object’s three-dimensional intensity distribution
    corecore