Surface-emitting lasers with an external cavity delivering a diffraction-limited beam have shown the potential to outperform edge-emitting devices in applications demanding high brightness (emitted intensity per unit solid angle), like pumping of doped fiber amplifiers or frequency doubling [1]–[3]. Due to the large mode size, the VECSEL concept is powerscalable by expanding the pumped area and...

We experimentally demonstrate diffraction from a straight edge in a medium with self-focusing nonlinearity. Diffraction into the shadow region is suppressed with increasing nonlinearity, but mode coupling leads to excitations and traveling waves on the high-intensity side. Theoretically, we interpret these modulations as spatially dispersive shock waves with negative pressure.

'Forbidden' Bragg reflections of iron orthoborate Fe(3)BO(6) were studied theoretically and experimentally in the vicinity of the iron K edge. Their energy spectra are explained as resulting from the interference of x-rays scattered from two inequivalent crystallographic sites occupied by iron ions. This particular structure property gives rise to complex azimuthal dependences of the reflection...

With the use of highly coherent femtosecond X-ray pulses from a free-electron laser, it is possible to record protein nanocrystal diffraction patterns with far more information than is present in conventional crystallographic diffraction data. It has been suggested that diffraction phases may be retrieved from such data via iterative algorithms, without the use of a priori information and witho...

Reflection energy from a linear reflector comes from an integrant over an aperture often described by the Fresnel zone. Within the Fresnel zone, the diffraction energy constructively builds the reflection energy. This paper uses diffraction theory to explain the reflector edge effect on amplitude and the amplitude variation within the Fresnel zone. Thus, discuss the Fresnel zone effect for AVO ...

The local adsorption site of the nucleobase uracil on Cu(110) has been determined quantitatively by energy-scanned photoelectron diffraction (PhD). Qualitative inspection of the O 1s and N 1s soft x-ray photoelectron spectra, PhD modulation spectra, and O K-edge near-edge x-ray adsorption fine structure indicate that uracil bonds to the surface through its nitrogen and oxygen constituent atoms,...

The methodology of multiple-wavelength anomalous diffraction, widely used for macromolecular structure determination, is extended to the imaging of nonperiodic nanostructures. We demonstrate the solution of the phase problem by a combination of two resonantly recorded coherent scattering patterns at the carbon K edge (285 eV). Our approach merges iterative phase retrieval and x-ray holography a...

We report the observation of optical vortices in a laser beam propagating through the stripe pattern of a cholesteric liquid crystal. The liquid crystal is confined in a cell with homogeneous boundary conditions and forms a diffraction phase grating. Optical vortices are produced by edge dislocations of the cholesteric grating. The vortices show up as spots of zero light intensity in the diffra...

INTRODUCTION In laser-scanning measurement of cylindrical objects extremely complex interfering signals occur. They are due to superimposition of reflected, unobstructed and scattered light. The proportions between these components vary in time and also the total intensity distribution changes. The considerations applying Fraunhofer theory are static and fragmentary, and may be concluded that t...