High resolution and high signal-to-noise ratio imaging with near-field high-order optical signals

The properties of near-field optics have always been the focus of nano-measurement technology. The 11th order effective near-field optical signal with an incident laser wavelength of 1,550 nm is obtained using a platinum-coated optical probe (Pt-Si probe). The experimental results show that the local electric field intensity of the Pt-Si probe is nearly 30 times higher than that of silicon probe (Si probe). Therefore, the highest 7th order near-field optical imaging results are obtained with the Pt-Si probe. Further, near-field optical imaging is performed on samples such as gold grids and carbon nanotubes using the Pt-Si probe. The measurement results show that the high-order signal has the characteristics of less background, higher signal-to-noise ratio, and resolution up to 5.7 nm.