Resolution improvement in digital holography: Comparison between synthetic aperture method and spatial averaging method

摘要

In the last two decades digital holography emerged as one of the most promising techniques for obtaining the complex object-wave (amplitude and phase). However, due to the coherent nature of the light source used in digital holography, the reconstructed hologram is subjected to speckle noise. Moreover, the resolution and size of the sensor employed in digital holography are smaller compared to the formerly used holographic plates in optical holography. This results in a reduced resolution for the reconstructed hologram. This paper discusses two resolution improvement methods, which are both based on the same recording process. However, the recorded data is processed differently to obtain a resolution improved reconstruction. The two methods are compared in terms of corresponding optical resolution, phase accuracy and processing time.