A new design for an electro-optically induced tilted phase grating inside a
waveguide is proposed. The electric field and the refractive-index distrib
ution induced inside a waveguide by voltage applied to two systems of inter
digitated electrodes that are shifted with respect to each other are calcul
ated rigorously on the basis of an original technique. The model accounts f
or the arbitrary electrode shift distance d (0 less than or equal to d less
than or equal to 2l), where l is the electrode spatial period. It is shown
that the proper choice of the shift can minimize the structure's capacitan
ce and consequently its time response. The refractive-index distributions a
re calculated for various schemes for application of electric potential and
electrode position that demonstrate the possibility of switching the direc
tion of the grating wave vector. It is shown how the concept can be use to
build electro-optically controllable transmissive (long-period) and reflect
ive (short-period) tilted gratings and couplers in both multilayered (trans
verse) and planar (lateral) configurations. (C) 2001 Optical Society of Ame
rica.