基于数字全息术的近场成像与应用

Digital Holography Based Near-field Imaging and Its Application

近场是指局域在物体表面附近亚波长范围内的空间区域。倏逝波存在于近场区域,可利用其与物质的相互作用特性对位于近场区域的某些介质样品进行高分辨率成像,及对样品物性变化进行高灵敏度测量,其中,基于全内反射和表面等离子体共振的近场成像与测量方法已在许多领域获得广泛应用。将数字全息术与这类近场测量方法相结合,可进一步有效解决自近场区域反射光波的相位分布的高精度全场动态测量问题。重点介绍基于全内反射数字全息术和表面等离子体共振全息显微术的近场成像方法与测量应用研究进展。

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.