Abstract: Ultra-short pulse laser has broad development prospects in the field of glass welding due to its unique advantages of high processing accuracy, small heat affected zone and high efficiency. In practical scenarios, glass often needs to enhance itself strength through strengthening to meet the reliability of its application. This article successfully realizes welding between chemically tempered glass using infrared ultra-short pulse laser. By observing the shape of welding spot with microscope, the regression equation of welding power, frequency, speed and laser welding joint size was summarized, and the accuracy of regression equation was verified. The results show that under the conditions of welding frequency 500 kHz and welding speed 10 mm/s, as the welding power increases, the mechanical strength of welding chemically tempered glass increases first and then decreases. The maximum shear stress of welding chemically tempered glass can reach 11.09 MPa, and the maximum tensile stress can reach 7.10 MPa. During laser welding, the chemically tempered glass is not only subjected to its own thermal expansion pressure but also superimposed tensile stress, so it is easier to cause damage to surrounding area.

Key words: chemically tempered glass, glass welding, infrared femtosecond laser, mechanical strength, nonlinear absorption, thermal expansion