基于光学Tamm态的石墨烯光调制器

Graphene Optical Modulator Based on Optical Tamm States

利用光学Tamm态(OTS)在金属-分布式布拉格反射镜(DBR)界面处的局域场增强和石墨烯的电控特性,提出一种基于OTS的石墨烯光调制器。利用有限元法和时域有限差分法对提出的调制器进行仿真研究。研究结果表明:当入射波长为850.7 nm时,在金属-DBR界面处会产生OTS,入射光的反射率比较低;当外加驱动电压大于7.5 V时,OTS的本征波长会发生漂移,入射光的反射率增大,可以实现强度调制。调制器的最大调制深度可达0.96,消光比为14.45 dB,在不考虑电路RC时间常数影响的情况下,调制速率超过600 GHz。该结构石墨烯光调制器在一定波长范围内,可以实现调制深度不同的光调制,在未来的光通信系统和光信息处理系统中具有很好的应用前景。

By using the local field enhancement of the optical Tamm state （OTS） at the interface of metal- distributed Bragg reflector（DBR） and the electronic control characteristics of graphene, we propose a graphene based light modulator based on OTS. The proposed optical modulator is simulated by finite element method and finite difference time domain method. The results show that when the incident wavelength is 850.7 nm, OTS can be engendered at the metal-DBR interface and the reflectivity of incident light is relatively low. When the driving voltage is greater than 7.5 V, the intrinsic wavelength of OTS drifts and the reflectivity of incident light increases, so that intensity modulation can be achieved. The maximum modulation depth of the optical modulator can be up to 0.96 and the extinction ratio is 14.45 dB. Without considering the effect of RC time constant on the modulation rate, the modulation rate is above 600 GHz. The proposed graphene modulator can be modulated with different modulation depths in a certain wavelength range. It has a good application prospect in the optical communication system and the optical information processing system in the future.