Apodized photonic crystal (PC) waveguide gratings are proposed to suppress sidelobes which appear in reflection spectra of usual PC waveguide gratings. By using specific functions (Gauss and Gauss-cosine functions) for the longitudinal refractive index distribution, it is possible to suppress sidelobes in the reflection spectra of PC waveguide gratings efficiently. The apodization is realized b...

Adjustable narrow band holographic reflective filter with the absolute diffraction efficiency about 95% has been recorded in the volume of photo-thermo-refractive glass Attenuation up to 20 times of transmitted beam was observed. Advantages of holographic filters in inorganic glass for laser power attenuation are discussed. © 2003 Optical Society of America OCIS codes: (230.1480) Bragg reflecto...

Double-resonant extremely asymmetrical scattering (DEAS) is a strongly resonant type of Bragg scattering in two joint or separated uniform gratings with different phases. It is characterised by a very strong increase of the scattered and incident wave amplitudes inside and between the gratings at a resonant phase shift between the gratings. DEAS is realised when the first diffracted order satis...

LLE Review, Volume 115 113 Introduction The OMEGA EP chirped-pulse–amplification system at LLE requires two 1.5-m large-aperture grating compressors to achieve high-energy petawatt capability.1 The current state-ofthe-art multilayer dielectric (MLD) diffraction gratings cannot meet this size requirement.2 Several institutes have explored the possibility of tiling gratings.3–6 Kessler and Cotel ...

We present a new interferometric technique to write apodized Bragg gratings. Along the fiber, two UV-pulses interfere with a variable time delay creating a gaussian apodization profile which strongly reduces the reflectivity side-lobes. This method allows writing of truly apodized gratings by single exposure of a uniform phase-mask. Introduction: In optical communication systems, applications o...

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...

The inscription of fiber Bragg gratings with femtosecond laser radiation gives access to a wide range of new materials beyond conventional UV-photosensitive and special hydrogen loaded materials. We have therefore investigated the use of an interferometric technique in combination with UV femtosecond laser pulses to generate fiber Bragg gratings in different types of fibers. Additionally, the t...

Chirped fiber Bragg grating (CFBG) provides an attractive solution for low cost dispersion compensation in a fiber optic transmission system. This kind of grating can be produced with a large chirp parameter and period sampled distribution along the grating length. The present work carries out the design optimization of a chirped FBG in respect of chirp bandwidth and apodization in achieving op...