High-resolution digital holography applied to micro-structure measurement

Digital holography has been demonstrated to be a useful tool in metrology. In this paper, the theoretical-limited resolution of digital holographic imaging system without pre-magnification is presented. The recording condition of off-axis lensless Fourier transform digital hologram is analyzed briefly. By using an automatic aberration compensation procedure proposed by T. Colomb, the computer simulation and the experimental investigation of wavefront reconstruction of a minute object are conducted. The results show that the intensity and phase imaging with high-resolution can be achieved by off-axis lensless Fourier transform digital holography. For a small noisy digital hologram, the automatic compensation procedure is a very effective method to reconstruct the digital holographic phase image. Moreover, the method is more suitable for the lensless Fourier hologram reconstruction.