Interdigitated electrode-induced phase grating with an electrically switchable and tunable period

A new design for an adjustable electro-optic phase grating inside a wavegui de is proposed. The electric field and the refractive-index distribution in duced inside a waveguide by voltage applied to double-sided periodic interd igitated electrode arrays are calculated rigorously on the basis of an orig inal analytical technique. The modeling was carried out with the Mathcad so ftware. It is shown that the fundamental periodicity of the induced grating inside the waveguide can be switched between l and 2l by application of th e appropriate voltage, where l is the spatial periodicity of the interdigit ated electrodes. One can also fine tune the peak grating reflectivity by ch anging the constant component of the induced refractive index with the help of the constant component of the electric field inside the waveguide. The suggested design can be used as a basic idea for a variety of optical commu nication networking applications, including switching, modulation, deflecti on, and data processing. (C) 1999 Optical Society of America OCIS codes: 13 0.2790, 050.1950, 060.1810, 160.2100, 130.3120.