Supplement Number 1

Representations of spontaneous polarization directions of ferroelectric domains in 'R' and 'O' crystals, detailed PFM imaging of the as-grown domain structure, optical images of the domain structure after the electric field is removed, corresponding time dependencies of the applied field, switching current, and charge under subsequent poling, domain-width distribution of multi-domain 'R-phase' laminar structure, optical images of the domain structure during polarization reversal, time-dependent optical response measurements, and experimental data on voltage-dependent photodetector signals under various conditions (free, closed, and open states).