Plasma Characteristics of Single Crystal Silicon Irradiated by Millisecond Pulsed Laser

In the air, Mach-zehnder interference system was set up to study the plasma expansion process of single crystal silicon induced by millisecond pulsed laser. Electron density is the main parameter of laser plasma characteristics. Calculation electron density of silicon plasma based on the relationship between the FWHM of Stark broadening of spectral line and the electron density. Experimental results show that: The existence material splash phenomenon is existence in silicon plasma generated by millisecond laser, the long pulse laser interaction with material has the thermal effect. Silicon plasma emission spectrum is strong in the distribution of the continuous spectrum, the discrete series of atoms and ions are superimposed on it. With the increase of the laser energy density, the electron density of the plasma increases.