Effective cleanliness in large laser contaminants control

Based on the current cleanliness standards, the definition of cleanliness only considers the size and the density of contaminations, ignoring the effects of different particles in laser-induced damage threshold. This article puts forward the effective cleanliness method, which contains the information of different chemical components in contaminations. The effective cleanliness method bases on the mass-transporting equation, combining with the previous standards. The calculation considers the molecular-level difference of contaminants of various classes. The result of the calculation on chemicals of the most amounts in LIL matches the experiment, proving the validity of this method. The effective cleanliness method provides a brand new assessment standard of contamination control in large laser engineering.