太赫兹波斜入射均匀非磁化等离子中传输特性研究

目的 研究太赫兹波斜入射均匀非磁化等离子体中的传输特性。方法 根据分层介质中的电磁波传播理论，给出了等离子中太赫兹波的功率反射和透射系数，分析了太赫兹波频率、入射角、等离子体的碰撞频率和电子密度对太赫兹波传输特性的影响。结果 垂直入射时，模型结果与已有文献结果一致；斜入射时，入射角度增大，反射系数增大，透射系数变小。太赫兹波频率增大，反射系数减小，透射系数起初快速增大，而后变得平缓。等离子体的电子密度增大，透射系数减小，碰撞吸收增大，太赫兹波衰减增大。结论 入射角变大，反射率增大。太赫兹波频率较低时，入射角对透射率影响明显。

Characteristics of Oblique Incident Terahertz Wave Propagation in Uniform Unmagnetized Plasma

Objective To research transfer characteristics of terahertz (THz) electromagnetic wave propagation in the un-magnetized plasma. Methods According to the theory of electromagnetic wave propagation in layered medium, the TE reflection and transmission coefficients were given. The effects of the incident angle and frequency of terahertz wave as well as collision frequency and electron density of plasma on the reflection and transmission were discussed. Results It was found that there were in good agreement with values of TE reflection and transmission obtained by the existing formulas and proposed models on normal incidence. With the increase of incident angle, the reflection coefficient increased and the transmission coefficient decreased during oblique incidence. With the increase of wave frequency, the reflection coefficient decreased and the transmission coefficient initially increased quickly, and then flattened. With the increase of the electron density, the transmission coefficient decreased, the absorption increased and the THz wave attenuation increased. Conclusion The incident angle increases, the reflectance coefficient becomes bigger. When the terahertz wave frequency is low, the incident angle has obvious influence on the transmission.