Polarization evolution on higher and hybrid-order Poincaré spheres with coaxial polarization holograms.

Based on the tensor polarization holography theory, we propose a simple and convenient method in the recording material, phenanthrenequinone-doped polymethylmethacrylate, to generate beams on higher and hybrid-order Poincaré spheres, and realize their polarization evolution on the spheres by combining the recorded phase with the Pancharatnam-Berry phase. By simultaneously adjusting the polarization azimuth angle and relative phase of the recorded waves, independent phase-shifts can be imparted onto two orthogonal circular polarization states in reconstruction process of polarization holography. The beams on basic Poincaré sphere are transformed into that on arbitrary higher or hybrid-order Poincaré spheres. We get the Poincaré spheres' type and polarization distribution of the reconstructed wave by interferometry and polarizer, and the results match well with the theoretical predictions.

Method for fabricating circular polarization beam splitters based on polarization holography.

Based on polarization holography, circular polarization beam splitters with separation angles of up to 100° have been fabricated. The left- and right-handed circularly polarized waves can be reconstructed by the two holograms that were designed by the tensor theory of polarization holography, respectively. In the fabrication of circular polarization beam splitters, two holograms were recorded only by the interference method in the same area of the polarization-sensitive material. This method is simple, inexpensive, and easy to adjust the separation angles and element size. The diffraction efficiency and the polarization state of the reconstructed waves were tested under different incident waves, and the experimental results are in good agreement with the theory. This work not only deepens our understanding of polarization holography but also expands the applications of polarization holography.

Generation of vector beams based on diffraction characteristics of a linear polarization hologram in coaxial recording.

Polarization holography is an effective tool for realizing light field manipulation and can be utilized to generate vector beams. Based on the diffraction characteristics of a linear polarization hologram in coaxial recording, an approach for generating arbitrary vector beams is proposed. Unlike the previous methods for generating vector beams, in this work, it is independent of faithful reconstruction effect and the arbitrary linear polarization waves can be used as reading waves. The desired generalized vector beam polarization patterns can be adjusted by changing the polarized direction angle of the reading wave. Therefore, it is more flexible than the previously reported methods in generating vector beams. The experimental results are consistent with the theoretical prediction.

Scalar vortex beams produced by Pancharatnam-Berry phase optical elements that utilize polarization holography.

We discuss the appearance of the Pancharatnam-Berry phase in polarization holography, and confirm the possibility of generating scalar vortex beams by using the Pancharatnam-Berry phase. The polarization holograms used to generate scalar vortex beams are produced in phenanthrenequinone-doped polymethylmethacrylate (PQ/PMMA), where each radial direction consists of an equivalent half-wave plate hologram with gradually changing directions. The spin angular momentum carried by a circular polarization reading wave is converted into orbital angular momentum in a reconstruction process, resulting in the formation of scalar vortex beams with positive and negative topological charges controlled by the reading polarization.

Polarization splitters with designable separation angles based on polarization holography of tensor theory.

We propose a simple and inexpensive method for the fabrication of polarization splitters with designable separation angles and a controllable active area, based on polarization holography of tensor theory. First, we design two polarization holograms that reconstruct waves with only p- or s-polarization components, respectively. Then, after we recorded these two holograms on the same position of the recording material using the interference approach, as a result, a polarization splitter could readily be prepared. The separation angles of fabricated polarization splitters can be easily adjusted by changing the interference angle, and the active area can also be easily modified by changing the sizes of the interference beams and recording material during the recording process. The experimental results verify the reliability and accuracy of this method. We believe that this work may broaden the application field of polarization holography.

Simultaneously characterized Stokes parameters of a lightwave utilizing the tensor polarization holography theory.

Polarization is a natural property of a lightwave and makes a significant contribution to various scientific and technological applications, due to the different states of polarization (SoP) of a lightwave that may manifest distinct behaviors. Hence, it is important to determine the SoP of the lightwave. Generally, the SoP of a lightwave can be recognized by the Stokes parameters. In this paper, we proposed a novel method to simultaneously characterize the Stokes parameters of a lightwave, by employing the tensor polarization holography theory. This is done through merely a piece of polarization-sensitive material. Compared with the traditional method, this method requires only one measurement to obtain all the Stokes parameters, without using additional polarizing elements. The experimental result shows excellent agreement with the theoretical one, which confirmed the reliability and accuracy of the proposed method. We believe that this work may broaden the application field of polarization holography.

Reconstruction characters of conventional holography using polarization-sensitive material.

Polarization holography, recording the amplitude, phase, and polarization of signal wave, may be regarded as the superposition of conventional holography and orthogonal holography. The former implies the signal and reference waves have the identical polarization state in the recording stage, while the latter means that they have the orthogonal polarization state. It is a common sense that in conventional holography, the polarization state of a reconstructed wave is always identical to that of the reading wave. However, predicted by the tensor polarization holography theory, which has been confirmed by many experiments, the polarization state of a reconstructed wave may be different from that of a reading wave. Hence, a question that may arise is which one is correct and why. In this work, we derive the electrical field of a reconstructed wave generated from the hologram that was recorded by the identical elliptically polarized wave at a large angle. The theoretical result shows that there are three kinds of reconstruction characters, and they are confirmed by the designed experiments well. Through the analysis, we find the key to observing that the recording material should be polarization-sensitive; recorded by a nonpolarization sensitive material, the polarization state of the reconstructed wave is always identical to that of the reading wave. The work not only verifies the tensor polarization holography theory, it also enlarges our understanding about conventional holography.

Diffraction characteristics of a linear polarization hologram in coaxial recording.

Diffraction characteristics of polarization holograms have important research significance and application prospects. In this paper, the Tensor theory was used to investigate the diffraction characteristics of a linear polarization hologram in a coaxial recording. The results show that, when the signal and reference waves are coaxial aligned, the sum of the polarized direction angles of two waves in the reconstruction process is equal to the sum of these in the recording process under the condition that, the gratings of recorded intensity response and the polarization response are in balance. The study on the diffraction characteristics of linear polarization holograms based on the Tensor theory in the coaxial recording may help us with a deeper insight into the polarization holography theory. Again, our results helped in the use of a proper design for the polarizer to change the polarization direction of the incident linear polarization waves.

Faithful reconstruction of linear polarization wave without dielectric tensor constraint.

Faithful reconstruction is a key and crucial point of polarization holography research, and has significant research interests in the field of holographic storage and image display. In order to realize faithful reconstruction of the reconstructed wave, the interference angle and dielectric tensor should be controlled. In contrast, we used the polarization holography theory described by tensor, and obtained the faithful reconstruction condition of linear polarization wave under arbitrary interference angle without any dielectric tensor constraint, which is further verified by experimental analysis.

Exposure response coefficient of polarization-sensitive media using tensor theory of polarization holography.

We report a method for measuring the exposure response coefficient of polarization-sensitive media using the tensor theory of polarization holography. According to the theory of polarization holography based on the tensor method, the exposure response coefficient of polarization-sensitive media is not only determined by the materials but also affected by the exposure energy. The exposure response coefficient changing with the exposure energy is the key factor in polarization holography for controlling the polarization state of the reconstructed wave. We summarize the change of the polarization state of the reconstructed wave with the exposure energy under different recording conditions and obtain the initial value (about 8.4) of the exposure response coefficient of the polarization-sensitive media. Finally, the null reconstruction of linear polarization wave is realized by using this initial value.