D27.9 ET4.1 1090nm 20KW Protective Window Fiber Laser Cutting Head Germany Material

d27.9 et4.1 protective window for high-power fiber laser cutting heads. fused silica optic with ar coating optimized for 1090 nm, rated for up to 20 kw in a properly maintained head. sits in front of the focus lens to intercept spatter, fumes and dust — keeping main optics cleaner for longer and reducing unplanned downtime.

size:

• diameter (d): 27.9 mm
• thickness (et): 4.1 mm
• quantity: 1 × protective window

spec:

• optimized for ~1090 nm fiber laser systems
• ar-coated surfaces to reduce reflection and power loss
• power handling: up to 20 kw in a correctly aligned and maintained cutting head
• precise thickness and surface flatness for stable cutting performance
• parallel faces to help maintain consistent focus and gas flow

material:

• quartz fused silica — germany-sourced optics
• low absorption and good thermal stability under high power
• durable ar coating for long service life

use:

• protective front window in fiber laser cutting heads
• shields the focus lens from dust, fumes and metal spatter
• helps extend focus lens lifetime and reduce unplanned downtime and cleaning stops

compatibility:

• for fiber laser cutting heads that use round protective windows at d27.9 mm / et4.1 mm
• commonly used on raytools, wsx, bodor type heads and similar designs
• always confirm your original window diameter and thickness before ordering

quality:

• each window visually inspected and packed in clean trays
• smooth edges and uniform coating for repeatable reliable performance in production environments