Visualization of ferroelectric domains in boracite using emission of terahertz radiation

الأصل · EN

We report on the emission of terahertz radiation by irradiation of femtosecond laser pulses in non-centrosymmetric paraelectric and ferroelectric phases of Co₃B₇O₁₃I boracite. The Generation of the terahertz waves in both phases is caused by optical rectification via a second-order nonlinear optical effect. In the ferroelectric phase, we successfully visualized ferroelectric domains by analyzing the polarization state of the terahertz wave radiated from the crystal. In a large area of the crystal (500 × 500 μm²), the observed polarization vector of the radiated terahertz wave was tilted from directions of spontaneous polarization, i.e., [100] cub, [010] cub, and [001] cub in cubic setting, which can be explained by the presence of a ferroelectric 90∘ domain wall of the (101) cub plane.