We report the spatial anisotropy of the acousto-optic (AO) figure of merit M2 in LiNbO3 crystals. The analysis is based on the indicative surfaces being calculated for several geometries of the AO diffraction. Basing on these results the most efficient geometries of AO cells made of LiNbO3 crystals are determined. It is revealed that the cells made of certain nondirect crystal cuts provide several times better AO diffraction efficiency comparing to the traditional ones, i.e., made of direct cuts of LiNbO3. The obtained results present considerable practical interest since may be useful in a designing of highly efficient AO cells made of LiNbO3 crystals. The methodology developed in the present work may be applied to other crystal materials as well.

The numerical method of the effective refractive index of porous composite materials calculation was improved by implementation of microlevel cellular structural models. The proposed solution gives the ability uniformly to analyse complex structural inhomogeneities and to synthesize the corresponding index based on the simulation of electrostatic field. The proposed realization is simpler and takes less computations capacities in comparison to analogous simulation methods. The method was probed on the example of SiO2 nanoporous matrix with refractive index n = 1.426 at λ = 2.71 µm wavelength. The results of simulation are in good agreement with other analytical models from literature.

Crystalline nanocomposite KDP/Al2O3 was obtained by growth of KDP nanocrystals inside nanopores of amorphous alumina matrix (Al2O3) with pores diameter of 35 nm. Performed atomic force microscopy and X-ray diraction analysis conrmed that Al2O3 matrix is lled up with a tetragonal phase KDP nanocrystals in preferred crystallographic orientation [100]. The nonlinear optical response was studied by means of second harmonic generation via the Maker fringe technique employing picosecond laser pulses at wavelength of 1064 nm. The polarization dependent second harmonic generation response was observed mainly due to the macroscopic crystalline structure anisotropy of KDP/Al2O3 nanocomposite. The investigation of such type of nanocomposites which combine nanoscale nonlinear optical materials has a great importance since they may improve the performance of entire system.

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