How to Choose the Right Lens?

In response to the problem of choosing the right beam splitter, they have conducted tests to determine how the effectiveness of laser marking is affected by different materials (such as fused silica, K9 glass, and zinc selenide). This helps users select the right beam splitter for their needs.It covers core parameter comparisons, material performance tests, and buying suggestions to help you improve your marking precision and efficiency.

When choosing a pair of polarized sunglasses, there are two important points to consider.

The prism is the heart of the laser marking machine, but there are many different materials on the market, and there is a huge price gap.Many users have told us that if a product is expensive they worry they will waste money, but if it is cheap they worry that it will be ineffective.In fact, there are two key factors to consider when choosing a lens: the application and material performance.

Step 1: Identify your needs.

First, consider what materials you are going to work with (metal, plastic, or ceramic), how precise you need to be, and how much you intend to use the machine. If you are engraving metal, you will need a machine that can withstand high power, and if you are working with fine patterns, you will need lenses with good light transmission and thermal stability.Listing these factors clearly will help you quickly narrow down your choices.

The second step: Material properties directly determine the effect.

Currently, the most popular materials are fused silica, K9 optical glass, and zinc selenide.We discovered through actual measurements that:

Fused silica lenses: These are resistant to high temperatures and damage. After working continuously for eight hours, the surface temperature of a fused silica lens rises only 12 ° C. They are suitable for high-power lasers, but are relatively expensive.

K9 Glass: Best value for money, with a light transmission rate of around 90 %, it is suitable for medium- and low-power marking. However, it is prone to minor charring on the edges when used for a long time.

Zinc selenide crystals are highly transparent to infrared light (more than 95 % transmissivity), and are suitable for precision processing. However, they are susceptible to moisture, and require the use of a drying apparatus.

Comparative testing: How much does the material affect the effect?

We did a comparative experiment using a 20-watt fiber laser.

When cutting 0.2 mm lines into 304 stainless steel, the amount of burring on the edge of the line is 40 % less than with K9 glass.

After 5,000 laser marks, the light transmission rate of the zinc selenide crystal lens was down only 1.2 %, while that of the K9 glass was down 3.8 %.

- When humidity is at 70 %, the depth of the mark on a zinc-selenium lens fluctuates by 15 %, clearly showing the effect of moisture.

These are all pitfalls you must avoid.

Don't blindly pursue high light transmittance: Some lenses claim to have a light transmittance of 98 %, but this is actually in relation to a particular wavelength. Before you buy, you must confirm that the lens matches the type of laser you use.

Anti-reflective coating is not a panacea: Anti-reflective coating can improve performance, but poor quality coating is not as durable as uncoated lenses. One user once bought a pair of coated lenses for a bargain price, but the coating peeled off after only three months.

This is both economical and efficient.

Based on the results of the tests, we concluded that there are three classic combinations:

1. Metal mass processing: Quartz glass lenses + air cooling system, which doubles the life of a regular configuration.

2. Small-scale engraving of craft items: K9 glass lenses + regular heat dissipation program, cost down 30 %

3) Precision laser marking: Zinc selenide lenses and a temperature / humidity controlled box allow for a precision of ± 0.01 mm.

Finally, we recommend that you clean the surface of the mirror with ethanol every quarter, but don ’ t rub it with a tissue. If the mirror has chipped or the coating has fallen off by more than 5 %, it ’ s best to just replace it, because using a damaged mirror will damage the laser.