He Xiaoyong, Liu Feng, Lin Fangting, Shi Wangzhou
Opt Lett. 2021 Feb 1;46(3):472-475. doi: 10.1364/OL.415187.
Based on 3D Dirac-semimetal (DSM) modified hybrid waveguides, tunable propagation properties have been investigated, including the effects of Fermi levels, structural parameters, and operation frequency. The results show that if the operation frequency is smaller (larger) than the transition frequency (≈2||), the proposed hybrid waveguides indicate strong (weak) confinement because the DSM layer manifests a high plasmonic (dielectric low) loss property. The dielectric fiber shape affects the propagation property obviously, as the elliptical parameter decreases, the confinement and figure of merit increase, and the loss reduces. With the increase in Fermi level, the propagation constant increases, and the frequency (amplitude) modulation depth is 32.31% (12.93%) if the Fermi level changes in the range of 0.01-0.15 eV. The results are very helpful in understanding the tunable mechanisms of hybrid waveguides and designing novel plasmonic devices in the future, e.g., modulators, filters, lasers, and resonators.
基于三维狄拉克半金属（DSM）修饰的混合波导，研究了其可调传播特性，包括费米能级、结构参数和工作频率的影响。结果表明，如果工作频率小于（大于）跃迁频率（≈2||），则所提出的混合波导表现出强（弱）限制，因为DSM层表现出高等离子体（低介电）损耗特性。介电纤维形状对传播特性有明显影响，随着椭圆参数减小，限制和品质因数增加，损耗降低。随着费米能级的增加，传播常数增大，如果费米能级在0.01 - 0.15 eV范围内变化，频率（幅度）调制深度为32.31%（12.93%）。这些结果对于理解混合波导的可调机制以及未来设计新型等离子体器件，如调制器、滤波器、激光器和谐振器非常有帮助。
