MAXIMIZING THE OUTPUT POWER OF A CO-2 LASER USING THE TAGUCHI TECHNIQUE

The capability of processing materials with a laser machine depends largely on the power of the output beam. Frequently, the design parameters that are fixed by the laser supplier may no longer be the optimal when there is a change in operating environment and a gradual deterioration of the laser components. This paper described the results of an experiment which was aimed at optimizing the output beam power of an industrial fast-axial-floW CO2 laser machine using the Taguchi method. Four control factors (design variables) were explored: blower speed, laser gas pressure, cooling fans, and output mirror transmittance. The various parameters were assigned to a modified L18 orthogonal array. The experiment was conducted with two repetitions and complete randomization within blocks was practiced. It was found that higher laser power could be obtained with a blower speed of 2526 rpm, laser gass pressure of 62 torr, cooling fans '' ON, '' and output mirror transmittance of 40%. The laser gas composition was kept constant at 5% CO2, 14% N2, and 81% He. Twenty confirmatory tests were performed and the results fell within the predicted 95% confidence interval. The result generated an improvement of 1.426 dB in quality gain, corresponding to an increase of 17.8% in output beam power.