Concept
Fresnel number
Related publications (34)
Longitudinal-differential interferometry: direct imaging of axial superluminal phase propagation
Hans Peter Herzig, Toralf Scharf, Myun Sik Kim
We introduce and demonstrate a new interferometric method called longitudinal-differential (LD) interferometry, which measures the spatially resolved phase difference of the scattered field by an object relative to the illumination. This method is combined ...
Optical Society of America2012Full-field microimaging with 8 keV X-rays achieves a spatial resolutions better than 20 nm
Fresnel zone plates (450 nm thick Au, 25 nm outermost zone width) used as objective lenses in a full field transmission reached a spatial resolution better than 20 nm and 1.5% efficiency with 8 keV photons. Zernike phase contrast was also realized without ...
Optical Society of America2011Measuring amplitude and phase of light emerging from microstructures with HRIM
Hans Peter Herzig, Toralf Scharf, Myun Sik Kim
Ultra high-resolution measurements of amplitude and phase fields emerging from fine period amplitude gratings are presented and discussed. In the axial direction periodically repeated features are found, whose origins are the Talbot effect within the Fresn ...
SPIE Digital Library2011Photonic Nanojet engineering: Focal point shaping with scattering phenomena of dielectric microspheres
Hans Peter Herzig, Toralf Scharf, Myun Sik Kim
We experimentally engineer Nanojets produced by dielectric spheres by varying the illumination and observe the effect with a high-resolution interference microscope (HRIM). Converging and diverging spherical wavefronts and Bessel- Gauss beams are considere ...
SPIE2011Photonic Nanojet engineering: Focal point shaping with scattering phenomena of dielectric microspheres
Hans Peter Herzig, Toralf Scharf, Myun Sik Kim
We experimentally engineer Nanojets produced by dielectric spheres by varying the illumination and observe the effect with a high-resolution interference microscope (HRIM). Converging and diverging spherical wavefronts and Bessel- Gauss beams are considere ...
SPIE2011Generation of a high depth of focus with constant transversal spot size using a phase-only pupil filter
Pramod Rastogi, Daniel Iwaniuk
A novel approach is proposed to obtain an extended depth of focus (DoF) in white light with constant transversal spot size within the DoF. It combines a phase-only pupil filter based on multiplexed radial zones with alternating quartic phase functions. The ...
Taylor & Francis2010Coherence and wavefront characterization of Si-111 monochromators using double-grating interferometry
A study of the coherence and wavefront properties of a pseudo-channel-cut monochromator in comparison with a double-crystal monochromator is presented. Using a double-grating interferometer designed for the hard X-ray regime, the complex coherence factor w ...
2010Infrared Measurements of the RF Output of 170-GHz/2-MW Coaxial Cavity Gyrotron and Its Phase Retrieval Analysis
Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge
We report the experimental results of the infrared measurements of output RF beam of the European 2-MW 170-GHz coaxial cavity gyrotron for ITER. The output beam profile is measured by the infrared thermographic technique using an infrared camera and a targ ...
2009Small Reconstruction Distance in Convolution Formalism
Christian Depeursinge, Tristan Colomb, Frédéric Montfort
Different numerical wavefront propagations in Fresnel approximation are proposed in digital holography. Standard convolution formalism fails for small reconstruction distances. We developed a simplified convolution formalism that is equivalent to the angul ...
OSA2008Fabrication of Fresnel zone plates for hard X-rays
A method to fabricate gold structures with high aspect ratio is presented. Fresnel zone plates with an outermost zone width of 100nm and structures of 1μm height are fabricated. Preliminary focusing results at an X-ray energy of 8keV are presented and ways ...
2007