Studies of melting ice using CO2 laser for ice drilling

•We melted snow and ice by CO2 laser.•The melting speed increases nearly in proportion to the laser intensity.•The melt-water accumulate in the hole reduces the melting speed.•We argue an optical-fiber-coupled laser drilling system.

A CO2 laser can be used to melt ice. Here we use a CO2 laser at 10.6 μm, a wavelength at which ice strongly absorbs, to drill (via melting) through ice. The resulting drilling speed is measured at several irradiation intensities, ice-snow densities, and beam angles relative to the horizontal axis. The speed increases nearly in proportion to the laser intensity. For an intensity of about 50 W/cm2, for instance, the melting speed is 4 mm/s for snow of density 153 kg/m3 and 0.8 mm/s for solid ice. Results also show that for downward beam angles, melt-water accumulates in the hole, reducing the drilling speed. Nevertheless, we also consider other laser mediums and argue that an optical-fiber-coupled laser drilling system could be used for drilling on glaciers and ice sheets.