Abstract:  Laser drilling has the advantages of high energy, high directivity, cleanliness, non-contact cutting drilling, etc. In the process of laser thermal melting through the ice, meltwater has a great impact on the laser penetration efficiency. In order to explore the influence of meltwater on laser penetration efficiency, CO2 laser with higher ice absorption efficiency was selected to conduct fixed-point penetration experiments on ice samples prepared by simulated polar ice cores under different irradiation angles and different laser power. The results show that when the negative incidence Angle is -90°--15°, the penetration velocity is 0.67-2.20 mm/s, which is only 21%-40% of the theoretical velocity, and the aperture reaches 3-5 times of the spot diameter. When the Angle of incidence is 15°-45°, the melt water is removed in time due to gravity, and the penetration velocity is 13.19-36.50 mm/s, which is 2.2-6.5 times of the theoretical velocity.

Key words: CO2 laser, fixed point perforation, meltwater influence, penetration velocity, aperture