We propose the optical implementation of diffractive optical elements onto electrically addressed liquidcrystal spatial light modulators. We compare the classic implementations onto amplitude-only or phaseonly domains with the implementations onto coupled phase and amplitude _spiral_ domains. We demonstrate that the coupling between amplitude and phase provides a trade-off between diffraction efficiency and the signal-to-noise ratio in the reconstruction. Furthermore, when investigating the influence of the maximum dephasing on phase domains and spiral domains through the use of optimal trade-off design, we show that phase-only domains with limited maximum dephasing can provide satisfactory performance. Finally, optical implementations are provided.