Beam shaping optics for YAG laser by using CNC lathe

A method for abeam shaping optics is proposed to convert a laser beam profile into required intensity distribution. A beam shaper with aspherical surface is calculated by Snell's law converted from measured irradiate beam profile to required profile. An acrylic resin is cut by a ball type grinding wheel consisted on diamond powder and polished by a cone type felt buff with alumina ceramics powder. A CNC lathe is used to control these tools position. A shaper with 4mm of thickness works to convert multi-mode beam profile with 13mm of diameter into a flat top cylinder with I mm of diameter. Its working distance is 60mm. Its transmittance is over 98%. It suceed to generate uniform melting mark of 0.6mm diameter on the steel target by YAG laser process.