Fiber Laser Cutting Machines
Glass Laser Cutting Machine
The Glass Laser Cutting Machine uses a Wuhan Huaray picosecond laser source at 30w, 50w or 70w to cut glass on a 500 x 400 mm marble work table.
Knowledge Centre
CO2 Laser Focus Lens
Published 2019-06-28 by the Weihua Laser engineering desk.
The Beam Path In A CO2 Machine
A standard CO2 laser cutter uses one laser path made up of one focus lens and three reflective mirrors. If the focus lens is dirty, scratched or mismatched to the application, the beam loses energy before it reaches the material. This results in wider kerfs, rough edges and slow cutting speeds that look like tube failure but are actually optics issues.
ZnSe Material And Sourcing
Zinc Selenide or ZnSe is the critical material for the focus lens because it transmits the 10.6 micron wavelength of a CO2 laser. The source text notes these lenses are made in China and imported from Singapore or America. Procurement teams should verify the material grade and origin when replacing optics, as inferior materials absorb heat and crack under high power.
Diameter And Focal Length Options
CO2 focus lenses typically come in diameters of 18 mm, 19 mm and 20 mm. Focal lengths range from 1.5 inch to 4 inch. For general engraving and cutting on Chinese laser machines, the 2 inch and 2.5 inch focal lengths are the most popular. Choosing the wrong focal length changes the spot size and depth of field, affecting cut quality on different thicknesses.
Matching Lens To Job Requirements
Shorter focal lengths like 1.5 inch or 2 inch create a smaller spot size for fine detail engraving. Longer focal lengths like 3 inch or 4 inch provide a deeper focus range, which helps when cutting thicker materials or when the table is not perfectly flat. You cannot use one lens for every job; stock the common sizes to maintain production flexibility.
Verifying Focus Length Before Purchase
Measure the physical focal length of your current lens or check the machine specification sheet. Ensure the diameter matches your lens holder. If you are upgrading power or changing materials, consult the technical support team to select the correct focal length. Incorrect optics cause poor cutting performance even if the laser tube is new.
Machines Mentioned Here
All machines
Fiber Laser Cutting Machines
HT Series Enclosure Metal Sheet Tube Fiber Laser Cutter
The HT Series is a fully enclosed fiber laser cutter designed to process both metal sheet and pipe on a single machine.
Fiber Laser Cutting Machines
ET Series Metal Sheet Tube Fiber Laser Cutter
The ET series is a fiber laser cutter for metal sheet and tube in one machine, offered as WH-3015ET, WH-4020ET and WH-6020ET.
Buyer Questions
Questions On This Topic
What material is the focus lens made of?
ZnSe or Zinc Selenide is the standard material for CO2 laser focus lenses because it transmits the CO2 laser wavelength effectively.
Which focal length should I buy?
2 inch and 2.5 inch are the most common for general engraving and cutting. Choose 1.5 inch for fine detail and 3 inch or 4 inch for thicker materials.
What are the standard lens diameters?
CO2 laser focus lenses typically have diameters of 18 mm, 19 mm or 20 mm. Check your machine's lens holder to confirm which size fits.
How many lenses are in a CO2 laser path?
A standard CO2 laser path consists of one focus lens and three reflective mirrors.
Where are the lenses sourced from?
The lenses are made in China and imported from Singapore or America, depending on the specific product batch and supplier.
Can I use the same lens for engraving and cutting?
You can, but performance varies. A 2 inch lens is a good compromise, but dedicated lenses for specific tasks often yield better edge quality or speed.
Still Not Sure Which Machine Fits
Send the material and the thickness. We answer with a model and the settings that go with it, not a catalogue.