Sawtooth grating-assisted phase-matching

Grating-Assisted Fibre-Slab Couplers

Coupled-mode equations for an asymmetric fibre-to-planar optical coupling system, incorporated a grating structure are presented. A grating-assisted coupling coefficient is described. When the parameters of the coupler are such that there is no phase synchronism between the fibre and the slab modes, the grating enhances the coupling in both the resultant amplitude and phase modulation. However,...

Phase Matching for Surface Plasmon Enhanced Second Harmonic Generation in a Gold Grating Slab

2k-Grating-assisted self-pumped phase conjugation: theoretical and experimental studies

We investigated 2k-grating-assisted self-pumped phase conjugation in photorefractive Ce:BaTiO3 crystals. The phase-conjugation process involves a combination of four-wave mixing and stimulated photorefractive backscattering. An approximation involving separate interaction regions is used to theoretically calculate the reflectivity of phase conjugation as a function of the coupling strength of f...

Grating-assisted phase-matched second-harmonic generation from a polymer waveguide.

Diffraction gratings can be used to achieve phase matching between the fundamental modes of a slab or confined waveguide. Compared with the usual techniques such as quasi-, Cerenkov, and intermodal phase matching, the matching method used here involves spatial harmonics of the guided electromagnetic field that are generated by the corrugated grating. This grating acts simultaneously as a linear...

Demonstration of three-port grating phase relations.

We experimentally demonstrate the phase relations of three-port gratings by investigating three-port coupled Fabry-Perot cavities. Two different gratings that have the same first-order diffraction efficiency but differ substantially in their second-order diffraction efficiency have been designed and manufactured. Using the gratings as couplers to Fabry-Perot cavities, we could validate the resu...