We observe experimentally two-dimensional solitons in superlattices comprising alternating deep and shallow waveguides fabricated via the femtosecond-laser direct writing technique. We find that the symmetry of linear diffraction patterns as well as soliton shapes and threshold powers largely differ for excitations centered on deep and shallow sites. Thus, bulk and surface solitons centered on ...

We present a technique to measure the velocity and flow profiles of a nanofluid in a microfluidic channel. Importantly, we extract the flow velocity from a series of standard brightfield images without employing particle tracking or laser-enhanced methods. Our analysis retrieves the flow information from the image structure function of sub-diffraction limited nanoparticles in suspension. We are...

Neutron diffraction and Extended X-ray Absorption Fine Structure (EXAFS) studies have been carried out on a range of praseodymium gallate glasses (Pr2O3-Ga2O3) prepared by aerodynamic levitation and laser heating. The short and intermediate range ordering around the rare-earth have been obtained by a multi-technique method. The results show that simple molecular dynamics simulations give a good...

Still diffraction patterns from peptide nanocrystals with small unit cells are challenging to index using conventional methods owing to the limited number of spots and the lack of crystal orientation information for individual images. New indexing algorithms have been developed as part of the Computational Crystallography Toolbox (cctbx) to overcome these challenges. Accurate unit-cell informat...

Classically, the grain size of soil and sediment samples is determined by the sieve method for the coarse fractions and by the pipette method, based on the ‘Stokes’ sedimentation rates, for the fine fractions. Results from the two methods are compared with results from laser diffraction size analysis, which is based on the forward scattering of monochromatic coherent light. From a point of view...

Title of Thesis: DIRECT LASER FABRICATION OF DIFFRACTION GRATINGS ON POLYMER THIN FILMS AND WAVEGUIDES Glenn D Hutchinson, Master of Science, 2005 Thesis Directed By: Professor Chi H. Lee, Department of Electrical and Computer Engineering With the increasing interest in polymer integrated optical devices, techniques for fabrication of efficient polymer diffraction gratings are of critical impor...

Direct laser writing has been already demonstrated for the fabrication of under surface “buried” 3D mid-IR waveguides in chalcogenide glasses by employing a large photo-induced refractive index change in the features formed in the path of the focused beam from a short pulse laser. In this paper, we report on direct laser writing of relief diffraction gratings with periods of 6, 14 and 24 μm int...

We present a fabrication technique and molecular beam epitaxy MBE regrowth of first-order, high contrast AlGaAs/GaAs diffraction gratings for laser emitting at 980 nm. An immersion holography technique is used to uniformly pattern first-order gratings with a pitch of 155 nm. MBE is used to overgrow Al0.75Ga0.25As on etched GaAs gratings. It is found that slow growth rates with optimum arsenic o...

introduction: dark or black coloured gingiva is an esthetic concern especially in subjects with high lip line or gummy smile. gingival depigmentation procedure is a type of perioplastic surgery where the gingival epithelium is excised with various techniques to lighten the colour of the gingiva. the aim of this study was to compare the clinical efficacy of gingival depigmentation procedure with...