Universal Laser Systems provides a variety of lenses to achieve the best result for laser cutting, engraving or marking on any material compatible with laser processing.
There are two primary considerations when selecting a lens for laser material processing: focal spot size and depth of focus.
- Focal spot size is a measure of the diameter of the area at the focal plane of a lens where the majority of the laser energy from the focused laser beam is concentrated. The smaller the focal spot size the higher the laser energy density.
- Depth of focus is a measure of the tolerance of a lens to deviations from the focal plane. A larger depth of focus indicates that the focal spot size increases at a slower rate with deviation from the focal plane.
The trade-off between the focal spot size and depth of focus occurs when a material processing application requires high power density and a small focal spot size. When this occurs, the material surface must be kept flat and accurately positioned near the focal plane. Lenses with larger depth of focus can accommodate more deviation from the focal plane, but with an overall decrease in energy density.
These attributes will also determine the focal length, which may need to be considered for processing requirements. Focal length is the distance from the final focus lens to the area, also called the focal plane, where the focal spot size is smallest.
The ULS modular architecture offers 4 lens types which can be easily changed based on your application and material needs:
- HPDFOTM (High Power Density Focusing Optics) – this unique lens assembly provides an extremely small focal spot and high energy density not otherwise achievable with a standard 2” focus lens. It provides sufficient energy density for direct marking of bare metals with a CO2 laser. The small spot size also provides a narrow kerf for efficient laser cutting of thin materials (less than 0.060” or 1.5 mm).
- 2.0 Lens – This is the most versatile lens. It provides an ideal balance of focal spot size, depth of focus and focal length for most laser cutting, engraving and marking applications.
- 3.0 Lens (ILS platform only) - This lens has a larger depth of focus and lower energy density. This lens can accommodate larger deviations from focus while maintaining a constant spot size, but with reduced overall energy density.
- 4.0 Lens (PLS6MW only) - This lens has the largest depth of focus and focal length selection.