Dynamic polarization filtering in anisotropically strained M-plane GaN films
Dynamic polarization filtering in anisotropically strained M-plane GaN films
复制标题
DOI：
10.1063/1.1927271
复制
发表时间：
2005-05
影响因子：
4
通讯作者：
K. Omae;T. Flissikowski;P. Misra;O. Brandt;H. Grahn;K. Kojima;Y. Kawakami
中科院分区：
文献类型：
--
作者：
K. Omae;T. Flissikowski;P. Misra;O. Brandt;H. Grahn;K. Kojima;Y. Kawakami
通过泵浦和探针光谱研究了 LiAlO2 上各向异性应变 M 平面 GaN 薄膜的动态光学偏振滤波。由于吸收系数非常大的偏振各向异性，这些薄膜表现出固有的偏振滤光，表现为线偏振光透过薄膜后偏振矢量的旋转。对于动态滤波，偏振旋转由泵控制，因为光激发载流子通过选择性漂白各向异性吸收来消除固有的线性二色性。偏振旋转的动态行为主要由两个最上面的价带之间的空穴重新分布和复合时间决定。后者与测得的约 15ps 的动态旋转衰减时间相当。对于M面GaN薄膜，最大动态旋转达到35°，而最大静态偏振旋转约为40°。
The dynamic optical polarization filtering for anisotropically strained M-plane GaN films on LiAlO2 is investigated by pump and probe spectroscopy. Due to a very large polarization anisotropy in the absorption coefficient, these films exhibit an intrinsic polarization filtering, which appears as a rotation of the polarization vector after transmission of linearly polarized light through the film. For dynamic filtering, the polarization rotation is controlled by the pump, since the photoexcited carriers remove the intrinsic linear dichroism by selective bleaching of the anisotropic absorption. The dynamic behavior of the polarization rotation is mainly determined by the redistribution of holes between the two uppermost valence bands and by the recombination time. The latter is comparable to the measured decay time of the dynamic rotation of about 15ps. For M-plane GaN films, the maximum dynamic rotation reaches 35°, while the maximum static polarization rotation is about 40°.