Barik A R, Adarsh K V
Opt Lett. 2017 Sep 1;42(17):3291-3294. doi: 10.1364/OL.42.003291.
In this Letter, we demonstrate for the first time that anisotropy can be induced at ultrafast time scales in an otherwise isotropic a-GeSe thin film using polarized femtosecond light. This photoinduced anisotropy (PA) spans the bandgap to the sub-bandgap region and self-annihilates over picosecond time scales. The ultrafast decay rate of PA is a clear indication that the observed effect is due to photoinduced transient defects in the sub-bandgap region and associated structural rearrangement in the near-bandgap region.
在本信函中，我们首次证明，使用偏振飞秒光可在原本各向同性的非晶硒化锗（a-GeSe）薄膜中在超快时间尺度上诱导各向异性。这种光致各向异性（PA）跨越带隙至亚带隙区域，并在皮秒时间尺度上自行湮灭。PA的超快衰减率清楚地表明，所观察到的效应是由于亚带隙区域中的光致瞬态缺陷以及近带隙区域中相关的结构重排。
