Fast control of the reflection of a ferroelectric by an extremely short pulse

We propose a new type of optical switch based on a ferroelectric. It is based on the gap which exists for waves propagating from a dielectric to a ferroelectric material. This gap depends on the polarization of the ferroelectric. We show that it can be shifted by a control electromagnetic pulse so that the material becomes transparent. This device would shift much faster than the relaxation time of the ferroelectric (1 nano s). Estimates are given for a real material.