Abstract-Visualization of ferroelectric domains in boracite using emission of terahertz radiation

http://arxiv-web3.library.cornell.edu/abs/1409.2960

Y. Kinoshita, N. Kida, M. Sotome, R. Takeda, N. Abe, M. Saito, T. Arima, H. Okamoto

(Submitted on 10 Sep 2014)

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.