Generally speaking, we use Jitai's 50s semiconductor laser module. It uses a 3mm laser rod, so the laser spot reflected by it is 3mm. The light spot of the galvanometer we generally use is 12 spots. In this case, it is more appropriate for us to choose a beam expander that is 12 divided by 3-----------4 times.

But everyone knows that the quality of the light produced by a large-magnification beam expander is better and the lines produced are thinner, so many equipment manufacturers want to use a 5x or 6x beam expander. mirror. But if you do the math, for 3mm emitted light, 3 times 5 equals a 15mm spot, and 3 times 6 equals an 18mm spot. Our galvanometer has 12 spots, so actually after the light from the beam expander enters the galvanometer, only the 12-spot laser will be reflected to the field mirror. In other words, you have 3mm or 6mm laser that is missed. It means that the laser actually loses 25% or 33%. This number is very large. In this case, although the lines we draw are thin, they will be very shallow.

Some people may say, what if I choose a 20-spot galvanometer? What will happen? Using a 20-spot galvanometer, all the light coming out of the beam expander can be reflected to the field mirror, but have you ever thought about a question? Our field lens is generally designed so that the incident light spot is 12mm, and the light coming out of the galvanometer is 15 or 18mm. However, our field lens can only be applied to 12 light spots, and the result is that the effect will not be good.

In short, the larger the beam expansion magnification of the laser beam expander, the better. Generally speaking, about 4 times is the most commonly used.