Efficient surface plasmon propagation on flexible free-standing and PMMA sandwiched graphene at optimized near to far-IR frequencies

Graphene is an important material for the design of flexible and stretchable electronic and optoelectronic devices on account of its high Young’s modulus and generation of highly confined surface plasmons. In this work, we report the near to far-infrared (FIR) input frequencies required to generate the maximum electric field and magnetic field for the efficient propagation of surface plasmons for differently doped, micron-long, free-standing and poly(methyl methacrylate) (PMMA) sandwiched graphene sheets. The effect of the variation of doping of graphene, graphene sheet length and bent angle of the graphene sheet on the propagating electromagnetic field is analysed at the obtained input excitation frequencies using finite element method. Low attenuation of 0.034 and 0.234 dB along with relatively high confinement of ~6 and ~13 nm for the surface plasmons are achieved for micron-long, bent, highly doped, freely suspended and PMMA sandwiched graphene sheets at 193.5 and 190 THz, respectively. The knowledge of these optimized NIR–FIR input excitation frequencies producing maximum electric and magnetic field output at the end of graphene sheet is useful for designing compact and efficient graphene-based flexible and wearable devices for medical imaging applications.