Femtosecond laser deep hole drilling of silicate glasses in air

Femtosecond laser pulses are ideal for many precise and delicate laser processing applications. In this work, we demonstrate that femtosecond laser pulses can be used to produce microscopic holes (<100 μm diameter) with macroscopic depth (>1 mm) in silicate glasses at atmospheric pressures. These experiments indicate that self-focusing is an important factor affecting hole depth at high laser intensity.