Klaus Benno Schildbach

Simple analytic model including shielding by the plume during excimer laser ablation of polyimide

For a quantitative description of the ablation of polyimide by excimer laser pulses in the nanosecond range, the concept of a moving surface during the pulse and of the shielding of its trailing edge by the plume is very essential. In a recent publication by Mahan et al.(1989) the concept of a moving interface was solved analytically. The main purpose of this paper is to include here the shielding effect. It will be shown that the resulting analytical formula describes most experimental data with surprising accuracy.

Excimer Lasers And Geometric Optics

The beam properties of a typical excimer laser with plane parallel mirrors can be approximately described from the geometric optics point of view as a superposition of ray bundles with locally varying angular distributions. These distributions have been measured by recording the far-field intensity after a small aperture shifted transversally through the beam. The characteristic differences to the situation at e.g. an incoherent source and an ideal laser with a stable resonator and the consequences for imaging are discussed within this framework.

Applications within the field of material processing

Binary phase gratings (Dammann gratings) are introduced as a new standard optical component within laser material processing applications and are shown to offer considerable advantages.