Fig. 1

Ferroelectric domain distribution in a tetragonal BiFeO₃ film and expected second harmonic generation results as coherent and incoherent contributions of multi-domains. a Piezoelectric force microscope image. Stripe-patterned domains are seen with two distinct orientations. b Schematic description of the second harmonic generation experiment. c Four types of stripe patterns of ferroelectric domains. d Polar plots of simulated second harmonic responses depending on a portion of different domains. Both coherent and incoherent summations are presented