f-theta lens

F-Theta Lens for Laser Marking, Welding & Cleaning

An F-theta lens is a precision laser scanning lens designed to ensure a linear relationship between scan angle and spot position on the working plane. Unlike standard focusing lenses, an F-theta lens maintains a flat field and constant spot positioning, which is critical for high-speed galvanometer scanning systems.

Shape Optics provides high-precision F-theta lenses optimized for laser marking, laser welding, laser cleaning, and micromachining. These lenses deliver uniform spot size, minimal distortion, high transmission, and excellent damage resistance, ensuring stable and repeatable processing results across the entire scan field.

 

Functions of an F-Theta Lens

F-theta lenses play a critical role in laser processing systems by:

  • Maintaining linear scan accuracy across the working area
  • Producing a flat focal plane for consistent processing depth
  • Minimizing spot distortion and field curvature
  • Supporting high-speed galvanometer scanning
  • Enabling large-area laser processing with uniform energy distribution

 

Applications

  • Laser Marking & Engraving
  • Laser Precision Welding
  • Laser Cleaning & Surface Treatment
  • Laser Cutting & Micromachining
  • Additive Manufacturing & Industrial Laser Processing

 

Key Benefits

  • High Laser Damage Threshold – suitable for high-power laser systems
  • High Optical Transmission – improved energy efficiency
  • Wide Scanning Range – supports large working fields
  • Excellent Spot Uniformity – consistent processing quality
  • Low Distortion & High Accuracy – ideal for precision applications

 

Product Specifications & Options

Shape Optics F-theta lenses are available for CO₂, fiber, green, and UV laser wavelengths, using optimized materials and coatings.

 

CO₂ Laser (10.6 μm) – ZnSe

Focal LengthScan AreaMaterialMax Input SpotMax AOI
100 mm70 × 70 mmZnSeΦ10 mm28°
200 mm140 × 140 mmZnSeΦ15 mm28°
300 mm210 × 210 mmZnSeΦ12 mm28°
420 mm300 × 300 mmZnSeΦ20 mm28°
574 mm400 × 400 mmZnSeΦ20 mm28°
720 mm500 × 500 mmZnSeΦ20 mm28°

 

Fiber Laser (1064 nm) – Optical Glass

Focal LengthScan AreaMaterialMax Input SpotMax AOI
160 mm110 × 110 mmOptical GlassΦ12 mm28°
290 mm205 × 205 mmOptical GlassΦ14 mm25°
420 mm300 × 300 mmOptical GlassΦ15 mm25°

 

Green & UV Laser – Optical Glass

WavelengthFocal LengthScan AreaMax Input SpotMax AOI
532 nm100 mm60 × 60 mmΦ14 mm20°
532 nm254 mm150 × 150 mmΦ10 mm25°
355 nm160 mm110 × 110 mmΦ6 mm28°

 

Customization Capabilities

  • Custom focal length and scan field
  • Wavelength-specific AR coatings
  • High-power and ultra-short pulse compatibility
  • Custom mechanical interfaces and mounts
  • Design optimization for specific galvo systems