[4] [4] WEN P, ZHANG Y Q, CHEN W Z. Quality detection and control during laser cutting progress with coaxial visual monitoring［J］. Journal of Laser Applications, 2012, 24(3): 032006.

[7] [7] ABELS P, KAIERLE S, KRATZSCH C, et al. Universal coaxial process control system for laser materials processing［C］//International Congress on Applications of Lasers & Electro-Optics. San Diego, California, USA： Laser Institute of America, 1999.

[8] [8] ADELMANN B, SCHLEIER M, NEUMEIER B, et al. Optical cutting interruption sensor for fiber lasers［J］.Applied Sciences, 2015, 5(3): 544-554.

[9] [9] ADELMANN B, SCHLEIER M, NEUMEIER B, et al. Photodiode-based cutting interruption sensor for near-infrared lasers［J］.Applied Optics, 2016, 55(7): 1772-1778.