Suppression of higher diffraction orders and intensity improvement of optically reconstructed holograms from a spatial light modulator

Abstract

Spatial light modulators (SLMs) can be used to optically reconstruct the complex amplitude of a wavefield. The reconstructed wavefield in the far-field is corrupted by effects arising from the non-ideal modulation properties and the discrete nature of SLMs. These effects are regarded as drawbacks and particularly disturb the visual impression and reduce the light efficiency of the reconstruction in the region of interest. In this paper we present a novel method to improve the quality of the reconstructed light field by eliminating the higher diffraction orders and by modifying hologram data based on the characteristic modulation properties of the SLM. We achieve the elimination of the higher orders optically using only one lens in a 4f configuration with an appropriate amplitude mask inserted in the Fourier plane. For compensating the non-ideal modulation properties of the SLM we characterize the device to alter the digital hologram data in an appropriate way. The basic principle of this technique and its experimental verification are described.