This high-quality protective optical glass, with a diameter of 38.1 mm and a thickness of 1.6 mm (JGS1 Fused Silica), is a specialized UPPER protective element used in high-power fiber laser heads. Positioned directly above the collimating lens, this glass forms a barrier that protects critical and expensive optical components from dust and microparticles that may enter the head during the connection or replacement of the fiber-optic connector (QBH). Thanks to its precise geometry and minimal thickness, this element does not introduce distortion into the high-energy-density laser beam.

The use of advanced, multi-layer anti-reflective (AR) coatings with a high optical damage threshold reduces energy loss to an absolute minimum. This prevents thermal lensing and ensures focal position stability during continuous industrial cutting at powers up to 15,000 W. This standard is fully compatible with modern fiber cutting heads from Precitec, Raytools, and WSX, used in advanced CNC cutting machines.