Multiple beam ultrashort pulse laser microprocessing

Abstract

A problem identified in the use of ultra short pulse lasers for the processing of materials has been that, to work close to the ablation threshold and hence avoid thermal damage, a large percentage of the available laser energy must be attenuated. The surface ablation of materials, using multiple diffracted beams generated by a Spatial Light Modulator (SLM), driven by Computer Generated Holograms (CGH) and synchronised with a scanning galvanometer system, has been shown here to result in flexible and high throughput parallel processing. By using multiple low energy beams, derived from a single higher energy beam, more efficient use of the available laser energy is made and process time is significantly reduced. The results demonstrate high precision microprocessing, showing the potential for ultra short pulse laser parallel processing in real industrial application. A review of the background of the use of SLMs in parallel processing is given, followed by examples of applications investigated.A problem identified in the use of ultra short pulse lasers for the processing of materials has been that, to work close to the ablation threshold and hence avoid thermal damage, a large percentage of the available laser energy must be attenuated. The surface ablation of materials, using multiple diffracted beams generated by a Spatial Light Modulator (SLM), driven by Computer Generated Holograms (CGH) and synchronised with a scanning galvanometer system, has been shown here to result in flexible and high throughput parallel processing. By using multiple low energy beams, derived from a single higher energy beam, more efficient use of the available laser energy is made and process time is significantly reduced. The results demonstrate high precision microprocessing, showing the potential for ultra short pulse laser parallel processing in real industrial application. A review of the background of the use of SLMs in parallel processing is given, followed by examples of applications investigated.