The diffraction characteristics of phase-type soft aperture with super-Gaussian transmittance were studied. It was proved that the phase-type soft aperture with super-Gaussian transmittance can improve the near-field intensity distribution of the beam and suppress the diffraction of the beam. Genetic algorithm was used to design the phase-type soft aperture, and was compared with the error diffusion algorithm. The design results demonstrates that the phase-type soft aperture designed by the genetic algorithm has a smaller RMS error and can suppress the diffraction modulation of the intensity in a large spatial range.
In this paper, a method based on point source and view-window is proposed that covers the features as full parallax, depth and accurate occlusion cue, shading and lighting, and ensures the computational efficiency in the meantime, to calculate the on-the-fly computer-generated holograms. With the acceleration of graphics processing unit (GPU), a bunch of point data of reconstructed image go through the pipeline of OpenGL and finish with coordinates transformation, fragment interpolation, lighting calculation, occlusion test, calculation and superposition of complex amplitude, and finally hologram are generated and loaded into the spatial light modulator (SLM). The experimental result shows that the lifelike complex full-parallax objects can be reconstructed at a high speed with varying gloss and accurate occlusion when viewed from different perspectives in the view-window.