Abstract
This paper investigates how structuring both the wavefronts and polarization can be used to shape the focal fields of ultrashort-pulse laser beams. Two Spatial Light Modulators in series are integrated within an industrial picosecond-pulse laser system and used to structure the beam vector fields, so as to produce a radial or azimuthal polarization with planar or vortex phase wavefronts, as well as induce Computer Generated Holograms (CGH). A detailed analysis of the focused vector fields is presented. Gentle surface ablation of highly polished metal samples is used to imprint Laser Induced Periodic Surface Structures (LIPSS) within the ablated areas. Thanks to their polarization dependent properties, LIPSS provide a direct means to visualize the polarization vectors in the focal region and highlight how shaping the wavefronts allows to control the focal fields of radially and azimuthally polarized beams. Furthermore, simultaneous ablation with diffractive parallel beams polarized radially and azimuthally is demonstrated.
Original language | English |
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Number of pages | 6 |
Publication status | Published - Nov 2015 |