Near-field optical virtual probe: a potential method for near-field storage

The virtual probe based on evanescent wave interference has a transmission efficiency of 10²-10⁴ times larger than an ordinary nano-aperture probe used in a near-field scanning optical microscope (NSOM). The FWHM of central peak of virtual probe keeps constant whatever distance in the certain range. It is possible that the interaction volume is beyond the diffraction limit and the interaction distance is 10 times the ordinary near-field distance owing to its characteristics. The distribution of the virtual probe could be influenced by the shape and size of the aperture, polarization of incident light etc. In the aspect of sidelobe suppression, the square aperture has a better effect than the round aperture and the parameters optimization of the aperture will be an important issue to be studied further. The characteristics of the virtual probe will make it possible to be used in application to near-field optical storage systems, nanolithography, near-field imaging and spectrum detection, and the near-field optical manipulation of nano-specimens.