Polarization-multiplexed diffractive optical elements fabricated by subwavelength structures

Abstract

Polarization-multiplexed phase-only diffractive optical elements with subwavelength structures are proposed and fabricated. The differences among the phase modulations result from the differences among the effective indices exhibited in the subwavelength structures with various filling factors and surface profiles, and the phase retardations are obtained by the relief depth of the structures. The polarization-selective property is achieved by the polarization dependence of the effective indices exhibited in the one-dimensional subwavelength structures and the polarization independence exhibited in the two-dimensional structures. Additionally, the polarization contrast of our polarization-multiplexed elements, defined as the cross talk between the two polarization incidences, is independent of the relief depth. The principle of the polarization multiplexing by use of the subwavelength structures is described, and the fabrication results for the polarization-multiplexed computer-generated holograms are demonstrated.

Synthesis of polarization-selective optical components with multilayer subwavelength structures

“…Rotating the device to make its TE axe have 45Û with respect to the polarizer axe and then measuring the intensities from the analyzer T TE and T TM , when its axe was parallel and perpendicular to that of the polarizer. The phase difference /3 resulted in the quarter-wave plate can be calculated from following equation TM TE TM TE I I T T )/ ( − = δϕ cos (5) The result from Eq. 5 was 86Û for the fabricated element.…”

“…Zeitner et al [4] demonstrated and fabricated a polarization-selective amplitude computer generated hologram based on the polarization-dependent transmission characteristics of metal-stripe SWSs. Yu et al [5] proposed a depth-independent phase-only polarization-sensitive computer generated hologram by introducing the polarizationdependent and independent form-birefringent SWSs to construct the corresponding pixels. The methods proposed in Ref.…”

Polarization Holographic Gratings Formed on Polymer Dispersed Liquid Crystals

“…Because of their optically active properties, polarization holographic gratings are promising in the production of high-function optical devices such as lights modulators, valves, polarization multiplexers and demultiplexers, polarized radiation splitters (Bunning et al, 2000;Cipparrone et al, 2000;Cipparrone et al, 2001a;Habraken et al, 1995;Ono et al, 2005;Wu et al, 2001;Yu et al, 2002). Such gratings are recorded on polarization-sensitive materials: photo-refractive crystals (Sturman et al, 1996), «guest-host» systems (Khoo, 1991;Slussarenko et al, 1997;Nikolova & Todorov, 1984), azopolymers (Naydenova et al, 1998;Labarthet & Rochon, 1999).…”

Polarization hologram with a low aspect ratio

“…The effective refractive index eff n depends on polarization and is given in following form by the second-order approximation [11][12][13]: …”