It is necessary to blow off the floating objects on the surface of the element by air ball, especially the lens with small particles and flocs on the surface. But never use compressed air on the production line, because the air contains oil and water droplets, which will deepen the pollution to the lens.
If the surface of the laser lens is not completely cleaned, it must be polished and cleaned. Polishing cleaning is to use fine grade (0.1um) aluminum polishing paste. This white liquid is dipped in cotton balls. Because this polishing cleaning is mechanical grinding, it is necessary to conduct slow and pressure free staggered circle during cleaning of lens surface, and do not exceed 30 seconds. Then use distilled water or dip in water with cotton balls to wash the surface clean.
After the polishing material is removed, the surface of the lens shall be cleaned with isopropyl alcohol. Isopropyl ethanol gathers the remaining polishing material with water and keeps it in a suspended state, and then removes the suspension with a cotton ball dipped with acetone. If there is any residue on the surface, clean again with alcohol and acetone until it is cleaned.
(1) Use acetone (or other cleaning solution, it is recommended that acetone) be used to clean the lens slightly. This level of acetone is almost water free, which reduces the possibility of lens contamination.
(2) Cotton balls dipped in acetone must be cleaned in light and moved in a ring. Once the cotton swabs are dirty, they must be replaced. Cleaning should be completed at one time to avoid the generation of wave bars.
(3) If the lens has two coated surfaces, such as the lens, each face needs to be cleaned in this way. The first side needs to be placed on a clean lens paper to protect it.
(4) If acetone cannot remove all dirt, then clean with acid vinegar. Acid vinegar cleaning is to use the solution of the dirt to remove the dirt, but will not cause damage to the optical lens. This vinegar can be experimental grade (diluted to 50% strength), or a white vinegar of 6% acetic acid used in the home. The cleaning procedure is the same as acetone cleaning, then use acetone to remove acid vinegar and dry the lens. At this time, frequently change cotton balls to completely absorb acid and hydrate.
If some pollutants and lens damage cannot be removed by cleaning, especially the film caused by metal spatter and dirt is burnt, the only way to restore good performance is to replace the lens.