Focusing mirror

Product introduction:
 
Laser focusing mirrors occupy a very important position in the laser system. The laser light path is changed by the refraction of the lens.
1. Scanning range
The larger the area that the lens can scan, the more popular it is. However, if you increase the scan area blindly, it will bring a lot of problems. If the spot is thicker, the distortion is increased, and so on.
2. Focal length (having a certain relationship with the working distance, but not equal to the working distance).
a. The scanning range is proportional to the focal length of the field lens - the increase of the scanning range will inevitably lead to an increase in the working distance. The lengthening of the working distance will inevitably lead to the loss of laser energy.
b. The spot diameter after focusing is proportional to the focal length. This means that when the scanning area reaches a certain level, the diameter of the obtained spot is large, that is, the concentration is not fine enough, and the power density of the laser drops very fast (the power density is inversely proportional to the square of the spot diameter), Conducive to processing.
c. Since the F-Theta field mirror works with the relationship of y'=f*θ, the actual values ofθand tgθ are still different. And as the focal length f increases, the degree of distortion will become larger and larger.
3. Working wavelength.
Most of the currently used on the market are 1064nm and 10600nm. However, with the development of later lasers, field mirrors of 532 nm and 355 nm and 266 nm will also have corresponding applications.

Function characteristics:
1. Improve the ability of the edge beam to be incident on the detector;
2. In the same main optical system, the additional field lens will reduce the area of the detector; if the same detector area is used, the field of view can be enlarged to increase the incident flux;
3. Uniform non-uniform illumination on the photosensitive surface of the detector.

Application:
Mainly used in laser marking machines, stage lighting, and also in scientific experiments and laser measuring instruments. The off-axis deflection phenomenon occurs when the laser beam passes through the focusing lens system in the marking system, and an abnormal image or distortion appears on the marking surface with respect to the ideal plane. The focusing mirror is a professional lens system. The purpose is to form a laser beam with a uniform size of the focused spot in the entire marking plane. It is one of the most important accessories for the laser marking machine. In the absence of deformation, the position of the focus point depends on the focal length of the lens and the tangent of the deflection angle. The position of the focus point depends only on the focal length and the deflection angle, thus simplifying the calculation of the focus position.

Cleaning and maintenance of laser focusing lenses:
1. The focusing lens material is ZnSe or zinc arsenic, which is brittle and brittle. Pay attention when disassembling: Do not use too much force and cannot collide with hard objects. There is anti-reflection film on the surface, which is afraid of pollution, fear of moisture, oiliness, and fear of scratching. Therefore, it is required to provide dry and degreasing air during work. Please use recommended cleaning equipment and cleaning method when cleaning.
2. The equipment must be operated with sufficient air pressure. Before working, put your finger to the exit of the focusing mirror (air nozzle) to check if there is gas blowing out? Is the air pressure sufficient?
3. Before starting the first work every day, remove the lens barrel with the focusing lens and observe if the focusing lens is contaminated. The principle of cleaning the focusing lens is: no pollution, no cleaning, no pollution, need to be cleaned in time!
4. Cleaning steps: ① Loosen the fastening screws and remove the air nozzle and the lens barrel in turn; first blow the dust off the surface of the lens with a blower; ②If you really need to clean the lens, you can only use the laboratory-grade paper. Soft cotton balls, take a proper amount of acetone or high-purity alcohol, gently rotate clockwise from the center of the lens to the edge. Both sides of the lens need to be cleaned when necessary, and care should be taken when cleaning. ③Install the lens barrel and the nozzle, adjust the focal length, and tighten the fastening screws.
5. If the focusing lens is too polluted or does not get effective cleaning for a long time, so that it cannot be cleaned, or the anti-reflection film on the focusing lens falls off, the focusing lens needs to be replaced.
6. The focal length of the general 2-inch focusing lens (reflected from the upper surface of the workpiece to the bottom of the nozzle) is about 6~7mm. The user can adjust the focal length according to the actual situation.
7. Keeping the focus lens clean is a powerful guarantee for cutting and engraving ability and effect.
8. When new equipment is newly installed with laser lenses, it is necessary to not force the lens to cause serious damage to the optical lens.

Common problem
(1) How to maintain the focusing tube?
A: The maintenance steps for focusing the lens barrel are as follows:
1. Take out the focusing mirror in the frame: loosen the fastening screw, and then remove the air nozzle and the lens barrel in turn; first blow the dust on the surface of the lens with a blower;
2. If you really need to clean the lens, you can only use a laboratory-grade paper soft cotton ball, take a proper amount of acetone or high-alcohol alcohol, and gently rotate clockwise from the center of the lens to the edge. If necessary, both sides of the lens need to be cleaned, and care should be taken when cleaning.
3. Install the lens barrel and the nozzle, adjust the focal length, tighten the fastening screw, and keep the convex surface facing down when the focusing mirror is installed.
(2) Is the laser-cut focusing mirror facing upwards or convexly facing up?
Answer: Laser cutting is the principle of using a convex lens to focus the parallel laser beam into a focus on the material to be melted and cut off. It is the same as the principle that the magnifying glass can point the paper to the sun. Only the energy of the laser can be much higher! The laser cutting machine focusing mirror is basically flat and convex. The convex side is facing up!
(3) How to choose the focusing mirror of the laser?
A: Mainly, focus on the size of the spot, working distance, laser wavelength, laser power.