Hybrid phonon-polaritons at atomically-thin van der Waals heterointerfaces for infrared optical modulation

作者：Zhang, Qing; Zhen, Zhou; Yang, Yongfei; Gan, Gongwen; Jariwala, Deep^*; Cui, Xudong^*

来源：Optics Express, 2019, 27(13): 18585-18600.

DOI：10.1364/OE.27.018585

• BORON-NITRIDE
• GRAPHENE PLASMONICS
• MOLECULAR-TRANSPORT
• NEGATIVE REFRACTION
• CRYSTALS

Surface phonon polaritons (SPhPs) in polar dielectrics are potential candidates for infrared nanophotonics due to their low optical loss and long phonon life-time. However, the small confinement factors of bulk SPhPs, limits their applications that require small footprint and strong light-matter interaction. Here, we report that ultrathin van der Waals dielectrics (e.g., MoS2 and h-BN) on Silicon Carbide enable ultra-confined dielectric tailored surface phonon polaritons (d-SPhPs) where the confinement factor can exceed 100. By creating a heterostructure of these vdW dielectrics with graphene, the d-SPhPs can hybridize with graphene plasmons which can be electrically tuned. By subwavelength patterning of the vdW dielectrics, these hybrid polaritons can be localized into ultra-small antenna volumes (lambda(3)(0)/v(antenna)(3)similar to 100(3)) with high-quality factor resonances (Q similar to 85). Further, electric gating of graphene enables active tunability of these localized resonances which results in an electro-optic modulator with modulation depth exceeding 95%. Our report of manipulating and controlling ultra-confined SPhPs in van der Waals heterostructures, serves as a possible route for non-plasmonic platforms for infrared photodetectors, modulators and sensors.

• 单位
  电子科技大学; 中国工程物理研究院