We present a non-contact optical investigation of laser-induced plasma at moderate Ar pressure ranging from 1 to 100 Pa.The significant shock front and spatial fractionation among the different charged ions are demons...We present a non-contact optical investigation of laser-induced plasma at moderate Ar pressure ranging from 1 to 100 Pa.The significant shock front and spatial fractionation among the different charged ions are demonstrated at the pressure of 20 Pa.The collisions between Si IV ions and ambient Ar atoms generate distinct and excited ArⅡions,fresh SiⅢions,and electrons at the dense layer.The electron density peaks at the position of the shock front,indicating that the collision that yields electrons is dominant over the recombination process in the region of the shock layer and its immediate vicinity.展开更多
In this paper,an effective method is proposed to generate specific periodical surface structures.A 532 nm linearly polarized laser is used to irradiate the silicon with pulse duration of 10 ns and repetition frequency...In this paper,an effective method is proposed to generate specific periodical surface structures.A 532 nm linearly polarized laser is used to irradiate the silicon with pulse duration of 10 ns and repetition frequency of 10 Hz.Laser-induced periodic surface structures(LIPSSs) are observed when the fluence is 121 mJ/cm;and the number of pulses is 1000.The threshold of fluence for generating LIPSS gradually increases with the decrease of the number of pulses.In addition,the laser incident angle has a notable effect on the period of LIPSS,which varies from 430 nm to 1578 nm,as the incident angle ranges from10° to 60° correspondingly.Besides,the reflectivity is reduced significantly on silicon with LIPSS.展开更多
基金supported in part by the National Natural Science Foundation of China(No.61805279)。
文摘We present a non-contact optical investigation of laser-induced plasma at moderate Ar pressure ranging from 1 to 100 Pa.The significant shock front and spatial fractionation among the different charged ions are demonstrated at the pressure of 20 Pa.The collisions between Si IV ions and ambient Ar atoms generate distinct and excited ArⅡions,fresh SiⅢions,and electrons at the dense layer.The electron density peaks at the position of the shock front,indicating that the collision that yields electrons is dominant over the recombination process in the region of the shock layer and its immediate vicinity.
基金supported by the National Natural Science Foundation of China (No. 61805279)
文摘In this paper,an effective method is proposed to generate specific periodical surface structures.A 532 nm linearly polarized laser is used to irradiate the silicon with pulse duration of 10 ns and repetition frequency of 10 Hz.Laser-induced periodic surface structures(LIPSSs) are observed when the fluence is 121 mJ/cm;and the number of pulses is 1000.The threshold of fluence for generating LIPSS gradually increases with the decrease of the number of pulses.In addition,the laser incident angle has a notable effect on the period of LIPSS,which varies from 430 nm to 1578 nm,as the incident angle ranges from10° to 60° correspondingly.Besides,the reflectivity is reduced significantly on silicon with LIPSS.
