We investigate numerically the interaction between two copropagating Bragg solitons in a fiber grating. We find that, in the low-intensity limit, the interaction is reminiscent of the nonlinear Schrödinger solitons in that Bragg solitons attract or repel each other, depending on their relative phases. However, the relative phase between two Bragg solitons is found to depend on their initial sep...

A detailed model of diffraction of Gaussian beams on plane uniform volume Bragg gratings based on a Kogelnik’s theory of coupled waves is presented. The model describes transmitting and reflecting gratings and takes into account spectral width and angular divergence of diffracted beams. Exact formulas for angular and spectral selectivity are derived. Conditions for Bragg diffraction based on co...

A passive all-fibre technique for fibre Bragg grating wavelength shift detection which has been discussed previously is used here for the demodulation of two Bragg sensors placed in a tree topology and addressed in time. The scheme involves a light source with a particular spectral profile that allows the direct tracking of the Bragg wavelength shifts, providing satisfactory resolution over a l...

optical tunable Bragg gratings in lithium niobate fabricated by direct femtosecond laser writing. The hybrid design that consists of a circular type-II waveguide and a multiscan type-I Bragg grating exhibits low loss ordinary and extraordinary polarized guiding as well as narrowband reflections in the c-band of optical communications. High bandwidth tunability of more than a peak width and near...

We report about the possibility of using regenerated fiber Bragg gratings generated in photosensitive fibers without applying hydrogen loading for high temperature sensor networks. We use a thermally induced regenerative process which leads to a secondary increase in grating reflectivity. This refractive index modification has shown to become more stable after the regeneration up to temperature...

We describe a novel, versatile process for fabricating integrated Bragg-grating devices. Our process addresses many of the critical challenges presented by such devices, including period selection, alignment, spatial coherence, and nanolithography. Using a combination of e-beam, x-ray, optical, and interference lithographies, we have successfully employed this process to construct 244 nm period...

We demonstrate that holographic Bragg reflector grating structures, which are photolithographically scribed in planar waveguides, support a unique approach to apodization and overlay that uses fixed-depth etching and partial contour writing to achieve continuous reflective amplitude control.

We report silica-based fibre Bragg grating filters with wavelength tuningspans well over 90nm using a simple set-and-forget beam bending tuning-package. The key operational parameters of the filters are maintained over the entire tuningwindow.

We derive nonlocal coupled-mode equations for a Bragg grating embedded in a medium with nonlocal nonlinearity. Using these equations, we study the oscillatory instability of nonlocal Bragg solitary waves and demonstrate that collisions between them result in fusion into a standing pulse or breather , possibly with generation of additional jets, in a broad range of parameters. The results are ex...

Potentially having a destructive influence on the mechanical properties of composite laminates, the invisible phenomenon of delamination frequently occurs under impact loading. In the present study, simulating the performance of long-gauge fiber Bragg grating sensors, impact-induced average strains within laminated composites are utilized to develop a delamination identification technique. Firs...