Spectroscopic analysis for machining of inorganic materials with the harmonics of a Nd:YAG laser

An analytical method of wavelength optimization for machining of inorganic materials with different harmonics of a Nd:YAG laser is presented here. The explicit quantitative expression for the intrinsic absorptivity of material is provided. Combining the absorptivity of material with the conversion efficiency of laser apparatus, the optimum machining wavelength is estimated by calculating the absorption efficiency. Reflectivities, absorptivities, and absorption efficiencies are examined for semiconductors and insulators, and their optimum machining wavelengths are given in tables. The optimum machining wavelengths are in descending order from metals to semiconductors and then to insulators.