Synthetic amplitude for improved reconstruction of non-iterative phase holograms

In this paper we show how a specially designed synthetic amplitude can be used to obtain greatly improved reconstruction of objects only using the phase data of their Fourier or Fresnel transforms. The reconstruction of objects from phase only information is of interest, since phase modulation has much higher efficiency than amplitude modulation and can be achieved with a high degree of precision with current liquid crystal on silicon spatial light modulators. However, direct reconstruction of an object from its phase information usually results in severely degraded outputs. Due this issue, to achieve optimal reconstruction, the object information must be codified in a phase hologram by means of time-consuming algorithms. To avoid these kinds of algorithms, we propose using a synthetic amplitude, designed in such a way that when multiplied with the phase information of the object leads to a high-quality reconstruction. This synthetic amplitude contains no information about the object, and can be used to reconstruct any amount of different inputs without need for further processing. We present experiments carried out in virtual and actual optical systems verifying the validity of our proposal for 2D, 3D and dynamic scenes.