Through the focusing and Q-switch

The principles and methods of laser cleaning laser is characterized by a high directivity,molybdenum plating, high coherence and high brightness. Through the focusing and Q-switch, the energy can be concentrated into a small spatial range and time range. In the laser cleaning process, the main advantage of the laser is the following characteristics: 1, the laser energy can be achieved in time and space on the highly concentrated, focused laser beam near the focus can produce thousands or even tens of degrees Celsius degrees, so that the dirt instant evaporation, gasification or decomposition. 2, the laser beam divergence angle is small, good direction, by condensing the laser beam system can be gathered into a different spot diameters. In the same conditions of laser energy, the control of different laser beam spot diameter can adjust the laser energy density, the thermal expansion of the dirt. When the expansion force is greater than the dirt stains on the substrate adsorption force, dirt from the surface of the object will be. 3, the laser beam can be generated on the surface of the solid ultrasonic wave generating mechanical resonance, the broken off dirt. Laser cleaning technology is the use of the characteristics of the laser beam so as to achieve the purpose of cleaning. According to the matrix material to be cleaned to remove dirt and being the optical properties of laser cleaning mechanism can be divided into two categories: one is the use of cleaning a substrate (also known as the parent) and surface adhesion (dirt) on a certain wavelength laser energy absorption coefficient has a great difference. The laser radiation to the surface of most of the energy is absorbed by surface adhesion, thereby heating or gasification evaporation, or instant expansion, and is formed of air driven from the surface, to achieve the purpose of cleaning. While the substrate due to the energy absorption wavelength of the laser is very small, will not be damaged. This type of laser cleaning, select the appropriate wavelength and control the size of the laser energy is the key to achieve safe and efficient cleaning. Another suitable for cleaning the surface of the substrate and attachment of the laser energy is not very different absorption coefficients, or substrate to form the coating heat sensitive acid vapor, or after heating the coating may produce toxic substances, etc. The cleaning method. Such methods are usually the use of high power, high repetition rate pulse laser impact the cleaning of the surface, so that the partial light beams converted into sound waves. Lower after hitting a hard surface acoustic wave, the return portion of the incident sound waves generated by the laser interference occurs, resulting in high waves, the coating small explosion occurs, the coating is pressed into powder, and then be vacuum cleaned, while the bottom of the base sheet but will not damage. From the analysis method, laser cleaning methods are four kinds: 1, the laser dry method, which uses a pulsed laser to direct radiation decontamination; 2, the laser + film method, a liquid film is first deposited on the surface of the substrate, and the laser radiation decontamination; when the laser is irradiated on the film, the film rapidly heated, explosive vaporization, explosive shock wave loose dirt substrate surface. And with the surface wave fly processing, to achieve the purpose of decontamination. 3, the laser + inert gas method in which laser radiation at the same time, with an inert gas blown to the substrate surface, when the dirt from the surface immediately after peeling from the surface by the gas blown to the surface again to avoid contamination and oxidation; 4, the use of laser so that the loose dirt, then use non-corrosive chemical cleaning. At present, the commonly used are the top 3 ways. Fourth method applies only to the cleaning stone artifacts, and a complete laser cleaning system comprising: a laser or a YAG laser), the sample processing units, optical system, console, auxiliary systems (such as the calorimeter, the beam Contour meter and its accessories). + Film of the laser cleaning method, as well as film deposition system. When using laser + inert gas cleaning method, you should also include inert gases to enter and troubleshoot the system