Study of femtosecond laser amplification in MgO:LiTaO$_3$ crystals with periodic nonlinear properties

This work presents a theoretical study of the parametric amplification process of optical radiation in crystals with periodic modulation of quadratic nonlinear susceptibility, using MgO:LiTaO$_3$ as an example. Special attention is given to analyzing the influence of basic factors such as linear absorption and dispersion on the process efficiency. It is found that in the infrared spectral range, linear absorption and dispersion effects significantly affect the signal wave amplification coefficient, determining the energy redistribution dynamics and spectral characteristics of the resulting radiation. The study introduces a novel approach to optimizing domain length relative to coherence length, achieving up to 18% efficiency through precise tuning, which surpasses previously reported results for similar materials. The obtained results are important for optimizing nonlinear crystal parameters, developing efficient parametric amplification schemes, and creating promising optical devices operating in the infrared range.