Image optimization of a computer-generated hologram by reusing zero-order beams and reflectors vibration.

In computer-generated holography, spatial light modulators are predominantly used for image reconstruction. However, the quality of the reconstructed images is often compromised by laser speckle and zero-order light diffraction. To address these problems, we propose the reuse of the zero-order beam, which not only eliminates the interference caused by zero-order diffraction in the reconstructed images but also considerably enhances image brightness.

A theoretical framework for general design of two-materials composed diffractive fresnel lens.

Near 100% of diffractive efficiency for diffractive optical elements (DOEs) is one of the most required optical performances in broadband imaging applications. Of all flat DOEs, none seems to interest researchers as much as Two-Materials Composed Diffractive Fresnel Lens (TM-DFL) among the most promising flat DOEs. An approach of the near 100% of diffractive efficiency for TM-DFL once developed to determine the design rules mainly takes the advantage of numerical computation by methods of mapping and fitting.