Improve K9 glass substrate damage threshold by HF etchingHF

This paper carries out researches on the chemical etching of HF acid on K9 substrates and calibrates the etching rate of HF acid under the concentration of 40% and 2%. The relationship between surface morphology of substrate and etching depth is analyzed and the effect of etching time, concentration of HF acid, ultrasonic cleaning on the LIDT is investigated. The optimized etching cleaning process which can reduce the deposition of silicate effectively and improve the LIDT is proposed. Finally, the optimized etching cleaning process is used to test and verify the experimental results. The results indicate that under the irradiation of 1064 nm laser, the LIDT of K9 substrates etched for 90s under the condition of high temperature and ultrasonic with 2% concentration HF acid is 75% higher than the original one.