Research on Ultra-Precision Lapping Technology for Super-Smooth Surface of KTP Crystal

The ultra-precision lapping processes to obtain the damage-free surfaces at Å level surface roughness of Potassium titanyl phosphate (KTiOPO4, KTP) crystal is studied in this paper. The influence of the lapping parameters on the stoke removal rate and surface roughness and material removal mechanism in the process of ultra-precision lapping process is discussed, and the evolution of the lapped surface is also observed with electric telescope. A super-smooth surface of quartz crystal with roughness Ra 0.8667 Å has been obtained by adopting the fine SiO2 abrasive powders and the elastic polyurethane pad in this study.