Anti-reflection film with high damage threshold is coated on both sides to reduce the loss caused by reflection and protect it from splash and other hazards Imported Shi Ying crystal material, uniform texture, high mechanical strength, high temperature and high pressure resistance, and the lens is not easy to crack and collapse Excellent substrate is selected, which has excellent optical performance and good thermal stability. The lens manufactured by slicing, polishing, grinding and other high-precision processes is resistant to high temperature and has strong laser performance.