Research Initiation: Study of Subthreshold Laser Illuminat-ion Effects in Solids Using Raman Scattering

拉曼散射将被用来观察和表征在皮秒脉冲重复照射下固体结构的逐渐变化。通过以0.1 cm-1的精度检测Stokes线的位移、展宽和线形变化，可以很容易地检测到塑性应变的积累和微晶的形成。其他候选人解释的前兆也会影响斯托克斯线。这些实验将首先在无序和结晶半导体(块状或薄膜)中进行，然后扩展到其他材料，如用于光学涂层的那些材料。结果将与现有的模型进行比较，并将确定前体的性质。

Raman scattering will be used to observe and characterize gradual structural changes in solids during repeated illumination by picosecond pulses. By detecting the shift, broadening, and lineshape changes of the Stokes line with an accuracy of + 0.1 cm-1, the accumulation of plastic strains and the formation of microcrystallites will be readily detected. Other candidates to explain the precursors will also affect the Stokes line. These experiments will first be performed in disordered and crystalline semiconductors (bulk or thin film), then extended to other materials, such as those used in optical coatings. The results will be compared to existing models, and the nature of the precursors will be established.