F-Theta scan lens (also known as a flat-field focusing lens) is a critical optical component specifically designed for 10.6μm wavelength CO₂ laser systems, widely used in laser marking, engraving, cutting, welding, and drilling applications. Featuring a unique distortion-compensated design, it satisfies the linear relationship y = f·θ (image height equals focal length times scan angle), unlike conventional lenses where y = f·tanθ. This characteristic ensures uniform focused spot size and linear scan rate across the entire workpiece plane without requiring electrical correction, enabling high-speed, high-precision processing operations.

Key Advantages

This product utilizes high-quality Zinc Selenide (ZnSe) optical materials with excellent thermal stability and low absorption characteristics. Combined with high-performance anti-reflection coatings, it achieves ≥98% transmission. ZnSe material is classified as a hazardous substance and is legally designated as a virulent poison; it must not come into contact with strong acids to avoid generating highly toxic hydrogen selenide gas. ZnSe CO₂ laser scan lenses are transparent to visible light, allowing red beam alignment for optical calibration.

The product is available in single-element, double-element, and triple-element optical designs to accommodate varying power levels and precision requirements. Focal lengths range from 45mm to 570mm, with scan fields from 16mm×16mm up to 500mm×500mm, meeting diverse application needs from fine marking to large-format cutting.

Technical Features

Telecentric design options ensure focused beams remain perpendicular to the workpiece surface even at the edges of the scan field, significantly improving drilling and cutting perpendicularity accuracy. Select models include ultra-hard DLC (Diamond-Like Carbon) protective windows to effectively prevent spatter damage during processing. The standard mounting interface is M85×1 thread, compatible with mainstream galvo scanning systems.