Peculiarities of photonic lattices recorded by Bessel beam technique in LiNbO3:Fe crystal

The aim of this work is the investigation of the peculiarities of recording of the refractive photonic lattices by Bessel beam technique in photorefractive Fe doped LiNbO3 crystal. Optical C-axis of the crystal was oriented along the crystal surfaces. The Gaussian laser beam at 532nm wavelength with 17.7mW is transformed into the Bessel beam by an axicon. The intensity pattern of non-diffracting Bessel beam is imparted into the photorefractive medium, being irradiated, via electro-optic effect, thus creating radially modulated refractive index photonic lattices. The annular refractive photonic lattice created inside the LN:Fe crystal has 10 μm period in radial direction. The recorded photonic lattice has been tested by probe beam. The direct observation of recorded lattice by phase microscope was also performed. The azimuthal dependence of created lattice was observed. The qualitative explanation is given.