High-precision femtosecond laser beam shaping in material processing

Laser beam shaping is the process of modulating the amplitude and phase of a laser beam. With the development of the spatial light modulator, laser beam shaping can modulate the light field to arbitrary pattern dynamically via the computer-generated hologram (CGH). Otherwise, femtosecond laser is widely used in material processing owing to its high peak power, low hot effect and nonlinear effects. However, femtosecond laser is not strictly monochromatic, which will introduce dispersion when femtosecond laser diffracted by a spatial light modulator, and deteriorate the effect of beam shaping. Here we present a method of high-precision femtosecond laser beam shaping. Experimental results confirm that the proposed method can be used to shape femtosecond laser beams into arbitrary patterns in the whole field of view (FOV) with the resolution near the optical diffraction limit.