In the general power output laser, all the lenses are mostly due to the manufacturing process or external pollution and other factors, which lead to the large absorption of the lens to the specific laser wavelength. As time goes by, the life of the lens is shortened, and the use or even shutdown of the lens is often affected due to the damage of the lens.
The increase of the absorption of the laser wavelength by the lens will cause the uneven heating, leading to the reflection of the lens and the change of the refractive index. When the laser wavelength passes through or reflects from the high absorption lens, the uneven distribution of the laser power will make the central temperature of the lens high and the edge temperature low. This change is called the lens effect in optics.
Due to the high absorption and heating of lens caused by pollution, many problems will be caused by lens effect. The irreversible thermal stress of the lens substrate, the power loss of the light beam propagating through the lens, the shift of the focus spot position, and the premature damage of the coating layer can all lead to the damage of the lens. For the lenses exposed to the air, we often do not follow the requirements and precautions for lens cleaning when cleaning. If we take materials casually, it will cause new pollution and even scratch the lenses, resulting in irreparable losses. Therefore, according to many years of experience, it is considered that no matter what kind of optical lens, it is the most important to keep clean. We should have good cleaning habits to carefully clean the lens, which can reduce or remove the pollution caused by human factors. Such as fingerprints and spittle flowers.
As a common sense, when operating the optical system by hand, you should wear fingertips or medical gloves regardless of cleaning, disassembly and installation. You should always follow the requirements and precautions for cleaning the lens. In the cleaning process, you can only use the specified materials, such as lens cleaning paper, cotton swab, reagent grade alcohol and high-purity alcohol to clean and disassemble any lens, Short cut installation will lead to shortened lens life, or even permanent damage. Therefore, we should use common sense to prevent the lens from being polluted by other reasons, such as moisture, smoke, dust and so on. After confirming that a lens is contaminated, we should use ear ball to blow the lens until there are no particles on its surface. Never blow it with your mouth. Because most of the air blown out contains oil and water, it will further pollute the lens.
If the surface of the ear ball is still contaminated after the treatment, we must use a special cotton swab dipped in laboratory grade acetone, ethanol, alcohol to gently wipe. This will remove most of the contaminated thin layers. The pollution of the lens in the laser will cause serious acquisition errors to the laser output and even the data acquisition system. If we can keep the lens clean, it will extend the service life of the whole machine.