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.