1. Beam expander:

The beam expander is an indispensable optical component in the laser marking machine system. It is actually two lenses with different focal lengths, but it plays a very important role.

The role of beam expander:

One is to make the focusing effect better and get a smaller focusing spot; the other is to evenly disperse the energy, so that the energy density reaching the vibrating lens or the mirror is reduced, making the vibrating lens or the 45-degree reflective lens more durable.

The product of the laser beam waist radius and the divergence angle is a constant value. Compared with an unexpanded beam, the divergence angle of an expanded beam can be focused smaller. The use of a beam expander with a spatial filter can change the asymmetric beam distribution to a symmetrical distribution, and make the light energy distribution more uniform.

2. Field lens:

Field lens is also called plan focusing lens and f-theta lens, which is a main component of laser equipment. Simply put, it determines the laser working range of the laser marking machine. It is mainly used to focus the light from the galvanometer on a plane.

The main function of the field lens:

1. Improve the ability of the edge beam to enter the detector;

2. In the same main optical system, the additional field lens will reduce the area of the detector; if the same area of the detector is used, the field of view can be enlarged and the incident flux can be increased;

3. Make the non-uniform illumination on the photosensitive surface of the detector uniform.

The size of the field lens corresponds to the power of the laser. When the power of the laser is constant, the increase in the scene will cause the energy of the laser to irradiate the surface of the object to be correspondingly weakened, thereby affecting the processing accuracy and quality. Therefore, in order to ensure the marking effect, when buying a laser marking machine, you should not blindly pursue a large range of scenes. It is necessary to select the appropriate equipment model and the corresponding field lens according to the actual processing conditions of the product.