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Picosecond and subpicosecond laser ablation of polymers

Pulsed laser ablation is well established as a universal tool for surface processing of organic polymer materials. The effect of pulse duration on the ablation process is extended to ultrashort laser pulses, of picosecond and femtosecond pulse width. The main advantages of using such very short laser pulses for the ablation of polymers is that heat diffusion into the polymer material is negligible an the energy loss into the sample is minimized. As a results the ablation threshold is reduced and also high precision patterning of the sample without thermal damage of the surroundings becomes possible. For transparent materials, in the corresponding ablation wavelengths, the mechanism of ultrashort pulse laser ablation is complex involving a multiphoton photodissociation process. Ablation rates of polymers have been measured by irradiating the polymers with a variety of laser sources. The laser sources use were producing pulses of picosecond and subpicosecond duration, in order to investigate comparatively the ablation efficiency and the phenomenology of the etched patterns.