Hard Biotissue Ablation With Ho:YAG Laser Under A Liquid Enviroment

Liquid assisted hard biotissue ablation with infrared pulse lasers can greatly enhance the ablation efficiency,reduce the thermal damage,and improve the accuracy of laser ablation.However,the underlying mechanism has not yet been explained.In the present paper,The dynamic evolution of the cavitation bubble and its interaction with hard bone tissue were monitored by a high-speed photography under water environment.The characteristics of cavitation channel,including its opening and following collapse,were detected carefully.The rule of tiny vibration on the target surface during the water-assisted laser ablation process was explored by small vibration amplification technology and the migration of cavitation was calculated by using Rayleigh equation.According to the characteristics of the bubble migration,the bubble movement period Tc wascorrected.Combined high-speed photography with pseudo-color image processing technique,the movement rule of the micro jet was further explored.The experimental results of liquid-assisted hard tissue ablationin the present study contributed to the theoretical explain for the ablation enhanced effect under environment and and further developed the fluid dynamics theory.