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The study of total light absorption due to excitation of localized surface plasmons on deep metallic crossed gratings having a sinusoidal profile with a two-dimensional periodicity shows a very strong increase in the electric field intensity, reaching 800 times the incident intensity. The region with high intensity is strongly localized at the groove top and is characterized by a volume much smaller than the diffraction limit, both in transverse direction along the grating plane, and in longitudinal direction when going away from the grating surface. The field enhancement and its localization are much more pronounced than in shallow gratings.

A monolithic double-grating phase mask comprising three short-pitch grating sections of spatial frequencies k_1 and k_2 collocated at one side of a substrate produces a large-period interferogram without higher harmonics to print in a photoresist film a latent grating of small spatial frequency equal to twice k_2−k_1. When incorporated in a write-on-the-fly scheme, the elements permit the fabrication of unlimitedly long gratings.

A linearly polarized plane wave impinging on a mirror-based waveguide grating is shown to experience a 2π phase shift of controllable slope in the reflection spectrum. Such a zeroth-order resonant grating effect is adequately confirmed by means of an ellipsometer. The close agreement between the analytical representation of grating coupled waveguide resonances with the experimental results confirms the relevance of the underlying phenomenological understanding of resonant gratings.

Bragg gratings are used in several photonic devices to reflect, and thus to isolate, specific wavelengths of light. Gratings can be photoinduced in chalcogenide glasses by illumination of bandgap light in an interference pattern. We used holographic interferometry to create Bragg gratings in amorphous As_2Se_3 thin films with a period of 0.56 µm by illumination with 633-nm light. The quality of the gratings was tested in real time, and refractive-index modulations as high as 0.037 were measured. These gratings were found to be stable over a period of several months if they were kept in the dark.

Bragg gratings are used in several photonic devices to reflect, and thus to isolate, specific wavelengths of light. Gratings can be photoinduced in chalcogenide glasses by illumination of bandgap light in an interference pattern. We used holographic interferometry to create Bragg gratings in amorphous As 2 Se 3 thin films with a period of 0.56 m m by illumination with 633-nm light. The quality of the gratings was tested in real time, and refractive-index modulations as high as 0.037 were measured. These gratings were found to be stable over a period of several months if they were kept in the dark.