Confinement of Bloch surface waves in a graphene-based one-dimensional photonic crystal and sensing applications

摘要

Bloch surface waves (BSWs) are excited in one-dimensional photonic crystals (PhCs) terminated by a graphene monolayer under the Kretschmann configuration.The field distribution and reflectance spectra are numerically calculated by the transverse magnetic method under transfer-matrix polarization,while the sensitivity is analyzed and compared with those of the surface plasmon resonance sensing method.It is found that the intensity of magnetic field is considerably enhanced in the region of the terminated layer of the multilayer stacks,and that BSW resonance appears only in the interface of the graphene and solution.Influences of the graphene layers and the thickness of a unit cell in PhCs on the reflectance are studied as well.In particular,by analyzing the performance of BSW sensors with the graphene monolayer,the wavelength sensitivity of the proposed sensor is 1040 nm/RIU whereas the angular sensitivity is 25.1 °/RIU.In addition,the maximum of figure of merit can reach as high as 3000 RIU-1.Thus,by integrating graphene in a simple Kretschmann structure,one can obtain an enhancement of the light-graphene interaction,which is prospective for creating label-free,low-cost and high-sensitivity optical biosensors.