High-efficiency and high-resolution apertureless plasmonic near-field probe under internal illumination

Near-Field Plasmonic Probe with Super Resolution and High Throughput and Signal-to-Noise Ratio

“…Then, the six annular slits couple and direct the excited SPP wave and ultimately boost the energy accumulation at the apex of the tip to achieve the superfocusing mode. 45 Figure 1b shows a scanning electron microscopy (SEM) image of a fabricated tip where a SiO 2 conical tip with a specifically aligned multiring structure was utilized as the body material. The inset shows an enlarged image of the tip apex, which is coated with a very smooth Au layer and sharp tip apex.…”

“…Because |Δφ sp − Δφ m | equals 2nπ, which satisfies the condition of Fabry−Peŕot resonance, the SPP wave propagates and constructively interferes at the tip apex, leading to the superfocusing mode with a spot size of 8 nm. 45,46 For example, we internally illuminated RP light on the backside of the p-tip to excite the SPP wave on the Au film. The spot size was approximately 6 μm, as shown in Figure 1c.…”

“…Here, the Au film supports the surface plasmon polariton (SPP) wave under the internal excitation of RP light from the backside. Then, the six annular slits couple and direct the excited SPP wave and ultimately boost the energy accumulation at the apex of the tip to achieve the superfocusing mode Figure b shows a scanning electron microscopy (SEM) image of a fabricated tip where a SiO 2 conical tip with a specifically aligned multiring structure was utilized as the body material.…”

“…Note that we optimized the performance of the p-tip by deliberately tailoring the locations of these annular slits to satisfy the phase matching condition between the phase delay of the SPP wave propagation, Δφ sp , and the phase delay of the excitation light propagation in media (i.e., SiO 2 in this case), Δφ m . Because |Δφ sp – Δφ m | equals 2 n π, which satisfies the condition of Fabry–Pérot resonance, the SPP wave propagates and constructively interferes at the tip apex, leading to the superfocusing mode with a spot size of 8 nm. , For example, we internally illuminated RP light on the backside of the p-tip to excite the SPP wave on the Au film. The spot size was approximately 6 μm, as shown in Figure c.…”