Frustrated total internal reflection evanescent switching

A mechanical chopper Q-switched CO2 pulse laser with high peak power, short pulse duration, high pulse repetition rate and moderate average power is developed. Using this laser, a multi-pass cutting process with high cutting speed is proposed for cutting hard and brittle materials such as engineering ceramics. Crack-free and fine cut is obtained in cutting Si3N4 ceramics. Moreover, the formation and elimination of the cracks are qualitatively analyzed in the paper.