Pyroelectric formation of planar waveguide structures in lithium niobate by laser beam with the wavelength of 532 nm

Formation of one-dimensional planar waveguides and couples of such waveguides within a bulk of undoped lithium niobate has been experimentally demonstarated. Waveguide structures with a channel size of 22 μm have been formed by the bright spatial solitons obtained at the compensation of the diffraction divergence of light beams in the crystal due to the contribution of the pyroelectric effect into the nonlinear response. The light wavelength was 532 nm and the optical power was ranged from 0.5mW to 1mW in experiments. The total compensation of the diffraction divergence at uniform heating of the crystal sample to the temperature from 75 ◦C.