基于数字全息术的近场成像与应用

The near-field region is confined within a subwavelength range from the surface of an object. Evanescent waves exist in the near field, and by utilizing their interaction with matter, near-field high-resolution imaging as well as high sensitivity detection of physical changes of some specimen within the near field region can be realized. Near-field imaging and measurement methods based on total internal reflection (TIR) and surface plasmon resonance(SPR) have a wide range of applications in many fields. By combining digital holography with these near-field measurement methods, accurate, dynamic, and full-field measurements of the phase distribution of a light wave reflected from the near field region can be achieved. This article mainly reviews near-field imaging approaches and measurement applications based on TIR digital holography and SPR holographic microscopy.