Simple method for generating special beams using polarization holography.

Vector vortex beams are a kind of special beam that simultaneously carry spin and orbital angular momentum. The generation of vector vortex beams usually requires a complex and expensive optical system, which becomes a bottleneck hindering its further application. Thus, a compact, low-cost and efficient special beam generation system is demanded. In this paper, a method that can produce vector vortex beams distributed anywhere in the equator of hybrid-order Poincaré Spheres based on polarization holography is proposed. Via changing some parameters of the device, this method can also produce the scalar vortex beams distributed at any position of the basic Poincaré Sphere and the vector beams distributed at the equator of the higher-order Poincaré Spheres. The work shows that polarization holography has the potential ability to regulate the spin and orbital angular momentum simultaneously, opening a new window for future research and applications of angular momentum space orientation.

Circular polarization detector based on polarization holography.

We propose and experimentally demonstrate the generation of a circular polarization detector based on planar polarization holography. The detector is designed by constructing the interference field according to the null reconstruction effect. We create multiplexed holograms, which feature the combination of two sets of hologram patterns and operate with opposite circular polarization beams. In a few seconds, the exposure operation allows the polarization multiplexed hologram element to be generated, with functionality equivalent to a chiral hologram. We have theoretically analyzed the feasibility of our scheme and experimentally demonstrated that the right- and left-handed circularly polarized beam can be distinguished directly depending on the different output signals. This work provides a time-saving and cost-effective alternative approach for generating a circular polarization detector and opens avenues for future applications in polarization detection.

Generation of circular polarization with an arbitrarily polarized reading wave.

Polarization holography has attracted considerable attention in recent years, due to its capability of recording the polarization information in polarization-sensitive material. Particularly, the faithful reconstruction (FR) can retrieve the polarization information of the recorded signal. To date, studies referring to these topics mainly concentrate on the interference between the same type of polarization such as linearly, circularly, and elliptically polarized light. In addition, most of the reading wave is strictly limited to some specified polarization state to achieve the FR. Here, we apply the linearly polarized light as the reference wave to record the circularly polarized light, and then the circular polarization state would be faithfully reconstructed by the arbitrarily polarized reading wave. We theoretically analyze its polarization characteristic based on the tensor theory and experimentally verified the analytical results. This result further extending the FR in polarization holography, and provides a practicable way to generate circular polarization which is easily fabricated. Moreover, the work would lay a favorable theoretical foundation for the future preparation of circular polarization generator and discloses a new insight in polarization manipulation for tailoring the optical field.