Zhang Xin, He Shan, Zhao Zhuan, Wu Pengfei, Wang Xuping, Liu Hongliang
Institute of Modern Optics, Nankai University, Tianjin, 300071, China.
Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology, Tianjin, 300071, China.
Sci Rep. 2018 Feb 13;8(1):2892. doi: 10.1038/s41598-018-20756-9.
In this report, an abnormal optical anisotropy in KTaNbO:Cu (Cu:KTN) crystals with refractive index gradient is presented. Contrary to general regulation in a cross-polarization setup, the transmitted intensity of both TE (horizontally polarized) and TM (vertically polarized) lasers aligned with the basic crystallographic directions can be modulated quasiperiodically. The mechanism is supposed to be based on the polarization induced by the temperature gradient and the refractive index gradient. Meanwhile, the correlated disorder property of the crystals in the range of the freezing temperature (T) and the intermediate temperature (T ) also plays an important role. With the results verified both theoretically and experimentally, we believe this work is not only beneficial for the development of the theory associated with the correlated disorder structures in relaxor ferroelectrics, but also significant for the exploitation of numerous optical functional devices.
在本报告中，呈现了具有折射率梯度的KTaNbO:Cu（Cu:KTN）晶体中的异常光学各向异性。与交叉偏振装置中的一般规律相反，与基本晶体学方向对齐的TE（水平偏振）和TM（垂直偏振）激光的透射强度均可被准周期调制。该机制被认为基于温度梯度和折射率梯度所诱导的偏振。同时，晶体在冻结温度（T）和中间温度（T ）范围内的相关无序特性也起着重要作用。通过理论和实验验证了结果，我们相信这项工作不仅有利于与弛豫铁电体中相关无序结构相关的理论发展，而且对于众多光学功能器件的开发也具有重要意义。
