In this article, a novel graphene based resonant free space modulator for modulating optical signals in the wavelength range of 1-2 μm is designed and numerically investigated. The presented modulator is highly versatile. It can function in both transmission and reflection regimes and is polarization insensitive and can be easily tuned to any particular wavelength. In this device, an ingenious Fabry-Perot (FP) cavity composed of concentric Au disks and rings and a single layer graphene is proposed. Incoming light is totally transmitted provided that the wavelength coincides the resonant wavelengths of the cavity, otherwise it is reflected. Hence, unlike common graphene modulators based on electro-absorption, here, the main role of graphene is to shift the resonant wavelengths of the FP cavity and its absorption is indeed negligible. Several highly efficient modulators are designed which can be summarized as follows: A transmission (reflection) type modulator with central wavelength of 1.55 μm, modulation depth of 95% (92%) at this wavelength, modulation depth of 48% (46%) in the wavelength range of 1.42- 1.63 μm (1.46-1.6 μm) covering entire C+S bands, insertion loss of 1.5 dB (1.3 dB) and gate voltage of 4.5 V (4.2 V). Other narrow band low voltage modulators requiring voltages of less than 1.5 V are designed either.

中文翻译：

---

石墨烯集成在环形法布里-珀罗腔中：近红外电信频段的偏振不敏感、低电压和可调谐光调制


在本文中，设计并数值研究了一种新型基于石墨烯的谐振自由空间调制器，用于调制 1-2 μm 波长范围内的光信号。所提出的调制器具有高度通用性。它可以在透射和反射状态下工作，并且对偏振不敏感，并且可以轻松调谐到任何特定波长。在该装置中，提出了一种由同心金盘和环以及单层石墨烯组成的巧妙的法布里-珀罗（FP）腔。如果波长与腔体的谐振波长一致，则入射光将被完全透射，否则将被反射。因此，与基于电吸收的常见石墨烯调制器不同，石墨烯的主要作用是改变 FP 腔的谐振波长，其吸收确实可以忽略不计。设计了几种高效调制器，可概括如下： 透射（反射）型调制器，中心波长为1.55 μm，该波长调制深度为95%（92%），调制深度为48%（46%）。波长范围为 1.42-1.63 μm (1.46-1.6 μm)，覆盖整个 C+S 波段，插入损耗为 1.5 dB (1.3 dB)，栅极电压为 4.5 V (4.2 V)。还设计了其他需要低于 1.5 V 电压的窄带低压调制器。