Near-field optical microscope is an important tool for the near-field optical test of micro-nano structure optical device.The scanning near-field optical probe is applied to test the near-field optical properties of nanohole.The near field intensity distribution of the nanohole is obtained and the near-field spot diameter is measured as about 120 nm.Test results show that the annular structure plays a positive role in focusing energy and enhancing transmission.This research may be the foundation for the pra...