Interferometry and shadow method observation millisecond laser interaction with silicon plate

Abstract

Studied steam velocity and observed liquid molten splash phenomenon during the millisecond laser interaction with silicon plate. First, the interference pictures are obtained about the millisecond laser interaction with silicon plate. The energy of the laser is 7.38 J, and the pulse width is 1 ms. The thickness of silicon plate is 0.3 mm. The results show, When the laser irradiated 233 μs, the front surface of the silicon plate has been generated gasification; and When the laser irradiated 466 μs, the back surface of the silicon plate also has been generated gasification. By two pictures of fringe locations and time intervals, during the laser irradiation 233-466 μs, the steam velocity is 27.52 m/s in the front surface of the silicon plate, and during the laser irradiation 466-699 μs, the steam velocity is 20.47 m/s in the back surface of the silicon plate which are calculated. Then, the shadow pictures are obtained about the millisecond laser interaction with the same silicon plate. The results show, When the laser irradiated 466 μs, the front surface of the silicon plate has been generated molten liquid splash phenomenon; and When laser irradiated 699 μs, the back surface of the silicon plate also has been generated. Meanwhile, Laser interaction with silicon plate at later, the front and back surface of the silicon plate appears molten liquid splashing at the same time, and splashing in the direction and other issues were discussed. Finally, use blackbody radiation theory, explained the reasons for melt splashing brightness higher than the illumination lightness.