Photoinduced insulator-to-metal transition and surface statistics of VO2 monitored by elastic light scattering
Photoinduced insulator-to-metal transition and surface statistics of VO2 monitored by elastic light scattering
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DOI：
10.1364/ao.54.002141
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发表时间：
2015-03-10
期刊：
影响因子：
1.9
通讯作者：
Aparicio, Joaquin
中科院分区：
文献类型：
--
作者：
Lysenko, Sergiy;Fernandez, Felix;Aparicio, Joaquin
为了统计分析VO2外延膜的非平衡过程，对一个半球内的超快光散射进行了测量。应用Gerchberg-Saxton误差减小算法精确计算光散射数据的表面自相关函数和部分重建功率谱密度函数。在VO2的超快光致相变过程中，弹性光散射表现出各向异性的晶粒尺寸依赖动力学。研究发现，相对于泵浦脉冲的偏振，跃迁速率取决于VO2晶粒的光吸收和取向。观测到的表面自相关长度和散射场的瞬态各向异性的逐步演化可能源于VO2晶格在亚皮秒时间尺度上的复杂多阶段转变。(C) 2015美国光学学会
Measurements of ultrafast light scattering within a hemisphere are performed for statistical analysis of nonequilibrium processes in VO2 epitaxial film. A Gerchberg-Saxton error reduction algorithm is applied for accurate calculation of a surface autocorrelation function from light scattering data and for partial reconstruction of a power spectral density function. Upon ultrafast photoinduced phase transition of VO2, the elastic light scattering reveals anisotropic grain-size-dependent dynamics. It was found that the transition rate depends on the optical absorption and orientation of VO2 grains with respect to polarization of the pump pulse. An observed stepwise evolution of surface autocorrelation length and transient anisotropy of the scattering field presumably originates from complex multistage transformation of VO2 lattice on a subpicosecond time scale. (C) 2015 Optical Society of America