Novel rectangular waveguides with graphene inserts biased by light are proposed herein. The graphene films short the conductor plates of waveguides and support the localized transverse-electric modes. Their electric fields are parallel to the wide walls of these waveguides, and the eigenmodes have decreased conductor loss. The designs do not involve the conductor and graphene strips with their sharp edges, and the loss associated with the current crowding effect is excluded. The waveguides are treated in the quasi-linear regime using a rigorous field matching method, and the complex dispersion eigenmodal equation is solved using a validated iteration algorithm. At the terahertz frequencies of amplification, where the real part of graphene conductivity is negative, a gain increase is found with the eigenmodal number. This gain can be tuned by the waveguide geometry, dielectric filling, and the level of quasi-Fermi energy. The ideal waveguide theory is corrected using a perturbation approach and the Drude model of surface resistance of waveguide plates.

本文提出了具有被光偏置的石墨烯插入物的新型矩形波导。石墨烯薄膜使波导的导体板短路并支持局部横向电模式。它们的电场平行于这些波导的宽壁，并且本征模降低了导体损耗。设计不包括导体和石墨烯带的尖锐边缘，并且排除了与电流拥挤效应相关的损耗。使用严格的场匹配方法在准线性状态下处理波导，并使用经过验证的迭代算法求解复杂的色散本征模态方程。在放大的太赫兹频率下，石墨烯电导率的实数部分为负，发现本征模数使增益增加。该增益可以通过波导的几何形状，介电填充和准费米能级来调节。使用微扰方法和波导板表面电阻的Drude模型校正了理想的波导理论。