Photonic waveguide structures in photorefractive lithium niobate with pyroelectric mechanism of nonlinear response

Compensation for the nonlinear diffraction of narrow laser beams with wavelengths of 532 and 633nm and the formation of photonic waveguides and waveguide circuits due to the contribution of pyroelectric effect to the nonlinear response of lithium niobate crystal have been experimentally demonstrated. Complete compensation for the linear and nonlinear diffraction broadening of light beams is obtained upon uniform heating of an undoped sample from room temperature to 55?C.