Optical properties including absorption, dispersion, group index, Kerr nonlinearity, and optical bistability of a three-level V-type atomic medium have modified by varying an external magnetic field. By changing the magnitude or the sign of the external magnetic field, the transparency window with normal dispersion transfers to the enhanced absorption with anomalous dispersion at the line center, and hence the light propagation switches between subluminal and superluminal modes. The magnitude and the sign of the Kerr nonlinearity are controlled with the strength and the sign of the magnetic field. As a consequence, the behaviors of optical bistability are also made to appear or disappear when switching on/off the magnetic field. Moreover, the threshold intensity and width of optical bistability are also changed by the magnetic field and the coupling field. The results can be used to control the working characteristics of applied devices and study the related effects.

中文翻译：

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通过改变外部磁场改变三能V型原子介质的光学性质

通过改变外部磁场来改变三能级V型原子介质的光学特性，包括吸收，色散，基团指数，Kerr非线性和双稳态。通过更改外部磁场的大小或符号，具有正常色散的透明窗口将转换为线中心处具有异常色散的增强吸收，因此光传播在子腔模式和超腔模式之间切换。Kerr非线性的大小和符号由磁场的强度和符号控制。结果，当打开/关闭磁场时，也使光学双稳性的行为出现或消失。此外，阈值强度和光学双稳态的宽度也被磁场和耦合场改变。结果可用于控制所应用设备的工作特性并研究相关影响。