Fig. 4: Simulation analysis of nanomembrane-wrapped microfiber structure for light–matter interaction.

a Left: schematic of a microfiber (MF) conformally wrapped by a nanomembrane (NM). Middle: electric field distribution of the LP₀₁ mode in a bare MF with a diameter of 5 μm (gray region). The blue region indicates the evanescent field outside the fiber, which is available for light–matter interaction. The pink curve denotes the NM boundary after conformal wrapping. Right: electric field distribution of the LP₀₁ mode after NM wrapping on the MF with D =  5 μm. b Variation of the electric field intensity and effective refractive index in MFs with different diameters when conformally wrapped with a VO₂ NM. c Distribution of electric field intensity among the MF core, cladding, and NM overlay layer as a function of MF diameter. As the MF diameter decreases, the field intensity in the cladding decreases, while the intensity in the NM overlay increases. d Electric field distribution and effective refractive index changes in a 10 μm-diameter MF induced by refractive index variation of the conformally wrapped VO₂ NM.