Beam shaping for microvia drilling

摘要

Single diffractive element flat top beam shaper. Commercially available since 1992 on a 355 nm UV Nd:Yag laser, the system employs a single diffractive optic that is matched to the size of the aperture. A single element design can provide a uniform profile at the aperture plane; however, due to the fast optical nature of the shaped beam4, it quickly degrades as edge diffraction is set in motion when the beam exits the aperture and propagates to the imaging lens.