Ultrafast Bessel Beam Enabled Glass Cutting with Ultra-Low Surface Roughness

Non-diffracting ultrafast Bessel beams provide an extended focal depth, enabling single-pulse formation of channels several hundred micrometres in bulk glass. When operated in regimes where near-field and far-field interactions coexist, the achievable structure size can be reduced to only a few nanometres, allowing fabrication of surface trenches on glass with a width below 10 nm. In this study, we perform glass cutting using ultrafast Bessel beams under conditions optimized to enhance near-field interactions to realize high–aspect ratio nanoscale structures. By tuning pulse duration, pulse energy, polarization, and scanning pitch, trenches approximately 100 µm deep and only a few nanometres wide are achieved. This results in the glass cut surfaces exhibiting significantly reduced roughness, demonstrating the capability of ultrafast Bessel beam processing to surpass current precision limits for extreme nano-structuring in glass.