Enhancement of second‐harmonic generation in LiNbO3 crystals with periodic laminar ferroelectric domains

Using the Czochralski method we have grown LiNbO3 crystals with periodic laminar ferroelectric domains whose half‐period nearly corresponds to the coherence length. Quasi‐phase‐matching for the nonlinear optical coefficient d33 has been approximately realized and enhancement of second‐harmonic generation relative to conventionally phase‐matched crystals of the same length has been observed.