含石墨烯四层平面波导TM振荡模的传输特性

Study on TM Oscillating Guided Modes in a Four layer Slab Waveguide Including Graphene

对含石墨烯四层平面波导TM振荡模进行相关研究.根据Maxwell方程组和切向边界条件,得到TM振荡模的色散方程和归一化芯层功率流方程,并根据得到的方程画出该模的相关特性曲线,进一步分析发现:随着频率的增加,有效折射率和归一化芯层功率流单调增加,且呈先慢后快再变慢的变化规律;波导厚度、模阶数对该模的有效折射率和芯层功率流具有明显影响,外加电压可对它们实现微调;当波导厚度为0.20 mm、频率在120 THz~250 THz之间时,基模在芯层中能传输最大功率流.这些新的特性,将有助于新型传感器和超薄型波导器件的开发.

The TM oscillating guided modes in a slab waveguide including graphene were investigated.According to Maxwell’s equations and tangential boundary conditions,the dispersive equation and another equation by normalized power flow in the core layer for TM oscillating guided modes were obtained.Besides,the correlation characteristic curves of the modes were plotted according to the obtained equation.Further analysis found that the effective refractive index and the normalized power flow in the core layer increase monotonically with the increase of frequency,and the change law is first slow,then fast and then slow.The thickness of the waveguide and the mode number have a significant effect on the effective refractive index and the power flows in the core layer,but he gate voltage can fine tune them.Furthermore,the TM fundamental mode can transmit the maximum power flow in the core layer when the waveguide thickness is 0.20 mm and the frequency is between 120 THz and 250 THz.These new features will benefit to the development of novel sensors and ultra thin waveguide in the future.