Dynamic laser protection window based on a topological state photonic crystal of a nonlinear LiNbO3 interface.

The accelerated advancement of high-energy laser technology has resulted in an increased necessity for multifunctional laser protection. Herein, we present an investigation into a static visible and dynamic 1064 nm laser protection window. Through studying the photonic crystal energy band structure and topological interface state properties, both 66.49% average visible light transmittance and 84.01% low-energy 1064 nm laser transmittance are achieved. The combination of a large third-order nonlinear effect of LiNbO₃ and strong light field localization of a topological interface state enables a 27.54 mJ/cm² protection threshold below that of traditional materials. This study offers what we believe to be new avenues for the development of multifunctional optical windows and novel optical elements.