Abstract
We have made the first calculations of i) the effect of an electric field on the structures corresponding to different phases exhibited by antiferroelectric liquid crystals (using a model proposed by us earlier), ii) the apparent tilt angle corresponding to these field distorted structures and iii) the conoscopic figures exhibited by such nonuniformly modulated structures with biaxial layers. The field induces new commensurate structures in the antiferroelectric, ferrielectric and SmCα* phases, the last one occurring between ferro and para electric phases. The results compare well with the available experiments, showing that the different structures predicted by the axial next nearest-neighbour xy-model are realistic.