Binary Fresnel zone plates (ZP) are one of the most frequently used focusing elements inplane optical schemes in micro- and nanophotonics. With a decrease diameter focal distance ZP to meso-wavelength sizes, parameters region begin be significantly influenced by features design (material, thickness, relief depth). The spatial structure spot formed near-field is investigated numerical finite (FE...

We describe a dual-color plasmonic lens suitable for focusing two femtosecond surface plasmon polariton wavefronts to a common focal spot. We show that the overlapping evanescent fields, which are confined to (sub-) micrometer dimensions, form a surface-selective excitation volume for four-wave mixing (FWM) experiments. We demonstrate that stable and virtually background-free FWM signals from s...

PURPOSE The purpose of this study was to evaluate the physiological uptake pattern of (18)F-FDG in the left ventricular myocardium of patients under preparation for tumor FDG-PET. PATIENTS AND METHODS We enrolled 188 patients without cardiac disease. The accumulation patterns were classified as either 'none', 'diffuse', 'focal' or 'focal on diffuse'. When a focal uptake was only observed on t...

Using a near-field scanning microscope (NT-MDT) with a 100 nm aperture cantilever held 1 μm apart from a microaxicon of diameter 14 μm and period 800 nm, we measure a focal spot resulting from the illumination by a linearly polarized laser light of wavelength λ=532 nm, with its FWHM being equal to 0.58λ, and the depth of focus being 5.6λ. The rms deviation of the focal spot intensity from the c...

For finite detector and focal spot sizes, here we propose a projection model for high spatial resolution. First, for a given x-ray source point, a projection datum is modeled as an area integral over a narrow fan-beam connecting the detector elemental borders and the x-ray source point. Then, the final projection value is expressed as the integral obtained in the first step over the whole focal...

Hollow glass tubes are in use at Cornell High Energy Synchrotron Source (CHESS) as X-ray optics in the 4 to 25 keV range to take large diameter, fairly parallel X-ray beams and compress them into smaller diameter, more divergent beams for various kinds of X-ray applications. The optics come in two forms: 1) multibounce condensing capillaries for making submicron diameter beams and 2) one-bounce...

A new plastic microlens array, consisting of 900 lenslets, has been developed for the Shack Hartmann wave-front sensor.The individual lens is 300 µm × 300µm and has a focal length of 10 mm, which provides the same focal size, 60 µm in diameter, with a constant peak intensity. One can improve thewave-front measurement accuracy by reducing the spot centroiding error by averaging a few frame memor...

A polymer-based graded index (GRIN with n= 1.4-1.6) waveguide lens was demonstrated on a semi-insulating GaAs substrate. The transparent bandwidth of the polymer film (photolime gel) is from -280 to -2800 nm. Therefore, UV (ultraviolet), visible and near-IR (infrared) light can be employed as the signal carrier wavelength. In this letter, an off-axis chirped grating lens working at 632.8 nm wit...