Diffuse second harmonic generation under the ferroelectric switching in Sr0.75Ba0.25Nb2O6 crystals

Abstract

In this work, we present observations of the polarization process in strontium barium niobate Sr0.75Ba0.25Nb2O6 (SBN-0.75) crystals by measuring the diffuse generation of the second harmonic converted by the random ferroelectric domains. The ability of a field-controlling intensity of the diffuse second harmonic generation is analyzed and discussed in terms of the specific switching scenario in SBN crystals.

Sum-frequency generation in disordered quadratic nonlinear media

“…[12][13][14] As the angular spectrum of planar SHG is directly related to the domain distribution this process can be used for k-spectroscopy 15,16 and to examine the switching behavior of ferroelectric domains. [17][18][19] Aside from noncollinear SHG the generation of the third harmonic via a cascaded χ (2) -process is also possible. 10,20 However, up to now noncollinear sum-frequency generation in SBN is not well examined.…”