Effect of incorporation of titanium dioxide nanocrystals on bulk properties of KDP crystals

The impact of titanium dioxide (anatase) nanocrystals on growth process, optical and structural properties of KDP single crystal was studied. As-grown crystals were characterized by High Resolution Three-crystal X-ray Diffractometer, optical diagnostics of elastic scattering, cone-shaped interference method, and spatial profile analysis method. In the composite system KDP:TiO2 the effect of giant nonlinear optical response of anatase nanoparticles was revealed, in particular in the intensity range up to 20 MW/cm2 the change of sign of the nonlinear refraction index was found. These results can be explained by the resonance excitation of defective states on TiO2 nanoparticle surface.

Research highlights
► KDP crystals containing TiO2 nanoparticles are grown.
► TiO2 nanoparticles are captured preferentially by the pyramidal crystal face.
► Two-dimensional ordering of TiO2 nanoparticles in the crystal bulk is established.
► TiO2 changes the sign and magnitude of the refractive NLO response of KDP:TiO2.