Coherent effect of four XeCl laser beams on a surface

The influence of the geometry of four beams of coherent XeCl laser radiation on the modification of thin films is studied. It is demonstrated that two-dimensional structures with parameters varying in space can be created by changing the orientation of the bisectrix of the angle between the laser beams with respect to the sample. The conditions necessary for the creation of perfect two-dimensional submicron structures on thin metal films are determined. The ratio of the size of the modified (distant) region to the period of the structure for typical experimental conditions was ~0.25. Submicron features of the modified area are shown to be highly sensitive to the duration and energy of laser pulses.