Ghaderi Goran Abad Mohsen, Valinezhad Mitra, Mahmoudi Mohammad
Department of Physics, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran.
Sci Rep. 2019 Apr 19;9(1):6312. doi: 10.1038/s41598-019-42710-z.
We theoretically investigate magneto-optical rotation (MOR) of a linearly polarized probe field in the four-level N-type cold atoms. By applying a static magnetic field and a weak coupling field, it is shown that the birefringence enhancement is induced in the system. Moreover, we show that the static magnetic field has a major role in switching the dichroism to enhanced birefringence in the system. We also obtain a large intensity for the output field with nearly perpendicular MOR angle by 88 degrees with subnatural width. It is demonstrated that Doppler broadening has a destructive effect on the MOR of the polarization direction of the probe field. The results of our study can be used for selecting narrow band of wavelengths and polarization converter for efficient switching of TM/TE polarization modes in optical communication, the depolarization backscattering lidar, polarization spectroscopy and precision measurements.
我们从理论上研究了四能级N型冷原子中线性偏振探测场的磁光旋转（MOR）。通过施加静磁场和弱耦合场，结果表明系统中会产生双折射增强。此外，我们还表明静磁场在将系统中的二向色性转换为增强的双折射方面起着主要作用。我们还获得了具有近垂直MOR角（88度）且具有亚自然线宽的输出场的高强度。结果表明，多普勒展宽对探测场偏振方向的MOR有破坏作用。我们的研究结果可用于选择窄波长带和偏振转换器，以实现光通信中TM/TE偏振模式的高效切换、去极化后向散射激光雷达、偏振光谱学和精密测量。
