Control of laser beam penetration depth during welding

A method for controlling fluctuations of laser beam penetration depth into the processed material is introduced. The method is based on small external modulation of the laser beam output power. Experimental evidence demonstrates that by applying sinusoidal modulation of a certain frequency, the fluctuations of penetration depth are reduced and a higher average penetration depth is achieved. These effects are reflected in some qualitative and quantitative characteristics of the fluctuations of plasma light emission detected during the process.