Research progress on defect theory of KDP crystals

Abstract

Potassium dihydrogen phosphate crystals are key materials in high-power laser, nonlinear optics, and optoelectronic functional fields. Internal defects are core factors determining crystal optical homogeneity, laser damage threshold, and service stability. This paper systematically reviews theoretical research progress on three typical defect types in KDP crystals: point defects, dislocations, and inclusions. It summarizes the application of theoretical methods such as first-principles calculations and phase-field models in defect characterization and mechanism analysis. Based on this, the paper discusses current theoretical bottlenecks in multiscale defect coupling, defect response under extreme conditions, and precise defect control. It also explores future directions for integrating theoretical calculations with crystal growth and processing techniques, providing theoretical guidance for defect optimization and performance enhancement in high-performance KDP crystals.