Abstract
We have developed a new optical system that transforms the circle profile beam generated with near Gaussian intensity distribution by a pulsed green laser (second harmonics of a Q-switched Nd: YAG laser) into a lineprofile beam. This transformed beam has uniform distribution to within 5% in the longitudinal direction, and is about 100 mm long and 40 μm wide. In the width direction, the laser beam is focused to the limited M2 value. For homogenization in the longitudinal direction, we employ a one dimensionnal waveguide plate type homogenizer. The laser beam is divided by waveguide plates, and the divided beams are overlapped on the surface of the works. We successfully reduced interference fringes by increasing the fixed optical pass difference beyond the inherent time and coherent length for every divided pair of adjacent beams under a controlled space coherent length.
