A GaAs-GaAlAs injection laser has been tested that confines light in the lateral dimension (normal to junction plane) by a multilayer Bragg reflector. In the past, light has been confined as a result of the higher-index guiding region and resulting evanescent fields.

Index-guiding photonic crystal fibers with appropriate structural parameters support the fundamental and second order modes over a practically infinite wavelength range. The polarization principal axes and mode field patterns of the modes can be made stable by having different size air-holes along the orthogonal directions. The potential applications of such two-mode PCFs are discussed.

We analyze theoretically and generate experimentally two-dimensional nonlinear lattices with periodic phase modulation in a photorefractive medium. The light-induced periodically modulated nonlinear refractive index is highly anisotropic and nonlocal, and it depends on the lattice orientation relative to the crystal axis. We discuss the stability of such induced photonic structures and their gu...

A Mg-ion in-diffusion process was applied to form an optical guiding structure in LiNbO(3) single-crystal fibers. A parabolic refractive-index profile was formed in a 56-microm-diameter, c-axis MgO:LiNbO(3) fiber, yielding quasi-single-mode (two modes) propagation.

This paper presents an astronomical study of a sample ancient cairns, stelae and burials at the cairnfield Xiis (Heis) in Somaliland, historic centre long-distance trade between different cultures. The analyses reveal set significant orientations that relates to seasonal movements region’s nomads, which are believed have remained unchanged for millennia. structures, date from first third centur...

A new model is presented for a step-index fiber in the form of an equivalent slab guiding structure. This model simplifies the analysis of fiber directional couplers and coupler half-blocks with dielectric and metallic superstrates. Simple empirical formulas to obtain the model parameters are also given. The use of this model is illustrated with some numerical examples.

We report on the phenomenon of trapping and switching of one-dimensional spatial solitons in Kerr-type nonlinear media with transverse periodic modulation of the refractive index. The solitons slowly radiate upon propagation along the periodic structure and are finally trapped in one of its guiding channels. The position of the output channel can be varied by small changes in the launching angle.