How to choose the appropriate lens for laser engraving machine

Choosing the appropriate lenses is crucial for the performance and engraving quality of laser engraving machines. Here are some suggestions on how to choose suitable laser engraving machine lenses:

1. Choose according to the type of laser engraving machine:
The common types of polymer lenses used in laser engraving machines are focal lengths of 50.8mm and 63.5mm.
The 50.8mm focal length polymer lens is suitable for cutting thin materials, while the 63.5mm lens is suitable for cutting thicker materials.
Therefore, when choosing lenses, it is necessary to determine based on the type of laser engraving machine and the thickness of the material to be processed.

2. Consider the transmittance and reflectance of the lens:
High transmittance lenses can allow more light to pass through, thereby improving the efficiency of laser use.
Lenses with low reflectivity can reduce the reflection of light, preventing it from reflecting and damaging the lens or affecting the quality of engraving.
Therefore, when choosing lenses, priority should be given to lenses with high transmittance and low reflectivity.

3. Pay attention to the quality and material of the lenses:
High quality lens materials have superior thermal stability and high laser transmittance, which can withstand higher energy densities.
Common lens materials include zinc selenide, which have excellent optical properties and stability.
When selecting lenses, it is important to ensure that their quality and materials meet the requirements for use.

4. Consider coating the lenses:
Coated lenses can utilize new technologies such as optical thin films and vacuum to increase the transmittance and UV and radiation resistance of the lenses.
Common coating types include hard film, multi-layer anti reflective film, and anti fouling film, which can enhance the durability and performance of lenses.
When choosing lenses, you can inquire with the supplier if they provide coating services and understand the type and effect of the coating.

5. Choose the appropriate lens size:
The size of the lens can also affect the effect of laser engraving. Generally speaking, the smaller the lens size, the finer the diameter of the focused light spot, and the relatively more concentrated the laser power, but the materials that can be processed are thinner.
On the contrary, the larger the lens size, the thicker the material that can be processed.
Therefore, when choosing lenses, it is important to select the appropriate lens size based on one's own processing needs.