F-theta Lens – Flat Field

F‑theta flat‑field lenses (also known as scan lenses or field lenses) are the core optical element in 2D galvo laser systems. They focus the steered beam onto a flat image plane, keeping the spot size and position consistent across the entire marking area—essential for high‑speed laser marking, engraving, etching, cleaning and drilling.

With EZCAD Software Development Kit, customers can integrate most of the functions of EZCAD2 to their own software or develop a new laser software like EZCAD2 for industrial automation or customized equipment, widely used in industrial laser galvo processing like marking, etching, engraving, welding, cutting…

Our flat‑field F‑theta lenses cover the most common industrial wavelengths—355 nm (UV), 532 nm (green), and 1064 nm (IR, including 1030–1080 nm fiber lasers)—with multiple scan fields and focal lengths. Standard M85×1 mounting threads ensure easy integration into mainstream galvo scanners (including Sino‑Galvo and Cambridge Technology‑compatible heads). High‑damage‑threshold AR coatings and fused‑silica/ optical‑glass options support stable operation in demanding production environments.Get a quote.

Why Choose Our F-Theta Lenses?

Superior Material: Made from high-purity Fused Silica F-theta lens material for minimal thermal expansion and high laser damage threshold.
Wide Compatibility: Standard mounting threads (M85x1 or others) ensure seamless integration with popular galvo scanner lens systems (like Cambridge Technology and Sino-Galvo).
Protected Coatings: Anti-reflection (AR) coatings are applied to maximize transmission and protect against environmental contamination.
Quality Assurance: Each lens undergoes rigorous interferometric testing to ensure wavefront accuracy.

Where F‑theta Flat‑Field Lenses Are Used

• Laser marking and engraving on metals, plastics, ceramics, glass and semiconductors.

• High‑speed coding, UID marking and batch marking.

• Surface texturing, annealing and cleaning.

• Precision drilling and via formation (e.g., PCB, flex circuits, thin foils).

• Large‑area flat‑field processing where a uniform spot across the full field is required.

If you are unsure which configuration best fits your application, please share your process requirements with our engineers for tailored recommendations.

Key Factors

• Wavelength: Use a lens specifically designed for your laser wavelength—355 nm for UV, 532 nm for green, and 1064 nm (or 1030–1080 nm) for fiber lasers. Mixing wavelengths can reduce performance and risk damage.

• Entry beam diameter / input aperture: Match the lens entrance pupil to the expanded beam diameter from your galvo scanner to maximize fill and spot quality.

• Scan field and focal length: A longer focal length supports a larger scan field but increases spot size; a shorter focal length yields a smaller spot but a smaller marking area. Choose based on both detail and throughput.

• Working distance and mounting: Ensure there is enough mechanical clearance between the lens and the workpiece; most industrial heads use the M85×1 mount thread for straightforward lens replacement.

• Laser power and damage threshold: For high‑power applications, prefer fused‑silica elements with high LIDT (laser‑induced damage threshold) and robust AR coatings.

• Coating and transmission: AR coatings should match your wavelength and power to minimize reflection and maximize transmission over long production runs.

• Environment and protection: In harsh environments, consider lenses with protective windows or sealing; avoid touching optics and clean only with approved methods.

Integration and Maintenance Tips

• Verify that the lens scan field and focal length match your galvo model and EZCAD/ control card configuration.

• Keep the lens and protective window clean; avoid abrasive cleaning and unauthorized disassembly.

• Periodically inspect for contamination or coating damage, especially in high‑dust or high‑power environments.

• When changing lenses, re‑check focus and field calibration to maintain marking accuracy.

Need Help Selecting a Lens?

Are you unsure which laser marking lens fits your machine? Do you need a custom telecentric F-theta lens for a specialized application?

Technical Support: Tell us your laser power, wavelength, and desired marking area. We will recommend the perfect model.Contact us for wholesale prices on replacement lenses.