Laser protective glass (also known as protective window, protective filter or welding protective window) can reduce the risk of mirror contamination during cutting or welding processes, and is also known as the "Z-end window".

Laser protective glass is usually made of quartz glass due to its material's high penetration rate in the ultraviolet and infrared ranges, low energy absorption, and high temperature impact resistance.

Choosing qualified protective lenses can reduce the risk of lens damage and downtime.

Optical glass is made by mixing high-purity silicon, boron sodium, potassium zinc lead, magnesium calcium, barium and other oxides according to a specific formula, melting at high temperature, and uniformly stirring with ultrasonic waves to remove bubbles; Then, after a long period of slow cooling, the internal stress is eliminated to form inorganic non-metallic material glass.

Glass with similar chemical composition and optical properties is also distributed in adjacent positions on the Abbe diagram. As shown in the Abbe diagram with a set of straight lines and curves, divide the Abbe diagram into many regions to classify optical glass; For example, crown glass K5, K7, and K9 are located in the K zone, while flint glass F2, F4, and F5 are located in the F zone. The symbols in glass names: F represents flint, K represents crown plate, B represents boron, BA represents barium, LA represents lanthanum, N represents lead-free, and P represents phosphorus.