We study the influence of few-layer graphene on omnidirectional photonic band gap (OPBG) in one-dimensional photonic crystal (1DPC) at terahertz frequencies. By periodically introducing few-layer graphene into 1DPC, the width of OPBG can be greatly broadened. As the layer number of introduced graphene increases, the broaden effect of the OPBG becomes stronger. The physical reason behind the broaden effect is that the few-layer graphene acts like an ultrathin metal layer within the frequency range of the OPBG. Besides, the width of the OPBG can be dynamically tuned by the gate voltage of graphene. Compared to 1DPCs containing metal layers, 1DPCs containing few-layer graphene possess lower absorptive loss and more flexible tunability. Our works provides a route and practical way to promote various applications based on tunable terahertz OPBGs.

我们研究了太赫兹频率下几层石墨烯对一维光子晶体（1DPC）中全向光子带隙（OPBG）的影响。通过周期性地将几层石墨​​烯引入1DPC，可以大大拓宽OPBG的宽度。随着引入的石墨烯的层数增加，OPBG的加宽效应变得更强。扩大效应背后的物理原因是，在OPBG的频率范围内，几层石墨烯的作用类似于超薄金属层。此外，OPBG的宽度可以通过石墨烯的栅极电压动态调整。与包含金属层的1DPC相比，包含很少层石墨烯的1DPC具有更低的吸收损耗和更灵活的可调性。我们的工作为基于可调谐太赫兹OPBG的各种应用提供了一种途径和实用的方法。