Second-harmonic generation from needlelike ferroelectric domains in Sr0.6Ba0.4Nd2O6 single crystals

Since Sr0.6Ba0.4Nb2O6 (SBN) is ferroelectric with a tungsten–bronze structure, numerous needlelike ferroelectric domains appear in a SBN single crystal when it is cooled through its transition temperature in the absence of a poling field. If the domains were illuminated by 1.06 μm radiation from a Nd:YAG laser, second-harmonic diffuse light was generated from these domains. This interesting effect, which can clearly be seen with the naked eye, will be used to generate all the primary colors using suitable lasers.