Interaction of CO2 Laser Radiation with Solids. II. Drilling of Fused Quartz

Abstract

A CW CO2 laser has been used to drill fused quartz sheets. The time dependence of hole depth and radius as a function of incident power in the range 20–150 W has been examined. Absorption of laser radiation at power levels above a critical value results in the propagation of a vaporization front into the solid. The velocity of this front is directly proportional to incident power for constant focussing. Resulting holes are funnel-shaped, tapering to [Formula: see text] in diameter from the initial focal diameter of [Formula: see text]. It is shown how these results can be generalized to provide a prediction of hole depth vs. absorbed laser intensity for other refractory oxide materials.