Increase of Side Band Powers in Parallel Phase Modulation by Lithium Niobate–based Electro-optic Crystal

An electro-optic Pockels cell can show very good optical switching behavior for its very good first-order non-linear effect. The response time or the switching time of this type of cell is also very fast. When an electric field is applied to it in a proper way, then it changes the propagation of a polarized light beam passing through it, for which there is found a change in refractive index occurring in it. The change in refractive index is linearly proportional to the applied electric field. This causes a change in optical path inside the material for the propagating light signal, which results in a phase modulation of the light beam. Electro-optic crystals were seen for massive uses in phase and intensity modulation–based all-optical long-haul communication systems. In integrated optics, this effect also has strong uses for processing of optical data. In this paper, the authors propose a new scheme where a single biasing electrical field is parallelly applied in two orthogonal directions at a time on a specific light signal, instead of one biasing signal on the light beam. This parallel application of biasing signal enhances the depth of modulation.