Prism-hologram-prism sandwiched recording method for polarization-selective substrate-mode volume holograms with a large diffraction angle

Abstract

We propose a prism-hologram-prism sandwiched recording method for the fabrication of polarization-selective substrate-mode volume holograms with a large diffraction angle. In fabrication, the C-RT20 photopolymer is sandwiched between two 45°-90°-45° prisms and the interference fringes can be easily recorded in the recording material. The experimental results are in good agreement with the theoretical predictions. The proposed method features of a reflection-type recording setup for a transmission element and belongs to a technique of longer-wavelength construction for shorter-wavelength reconstruction. In addition, the method is much easier than the traditional recording method of two incident beam interference and has application potential in holographic photonics.

Design and Fabrication of a Holographic Radial Polarization Converter

“…Firstly, the polarization-selective volume hologram gratings (PVHGs) were recorded with photopolymer film (C-RT20, Litiholo) (n pp = 1.501, d = 16 µm) with a 632.8 nm He-Ne laser. As shown in Figure 4, a prism-hologram-prism sandwiched recording setup was adopted for the recording [18]. In fabrication, the photopolymer film was sandwiched between two right-angle prisms with a base angle θ p1 of 45 • for recording.…”

“…Meanwhile, the PVHG has a white appearance when p-polarized light is incident. According to the geometry of prism-hologram-prism sandwiched recording setup, the reconstruction wavelength λ2 (operating wavelength) can be tuned by changing the recording wavelength λ1 or the base angle θp1 of applied right-angle prisms [18]. In Figure 8a, the relationship of reconstruction wavelength λ2 versus recording wavelength λ1 is depicted with relevant thickness and refractive index parameters.…”

“…As shown in Figure 8b, considering a specific recording wavelength of 632.8 nm, the reconstruction wavelength λ2 (operating wavelength) can be continuously tuned form 300.05 nm to 617.73 nm when the base angle θd of prism changes from 61.56° to 5°. In comparison, changing the According to the geometry of prism-hologram-prism sandwiched recording setup, the reconstruction wavelength λ2 (operating wavelength) can be tuned by changing the recording wavelength λ 1 or the base angle θ p1 of applied right-angle prisms [18]. In Figure 8a, the relationship of reconstruction wavelength λ 2 versus recording wavelength λ 1 is depicted with relevant thickness and refractive index parameters.…”

“…By contrast, volume hologram gratings can be an alternative feasible solution for the radial polarization converter, which provide superior characteristics of high diffraction efficiency, thin and compact plane configuration, easy coupling of light, low cost, and are suitable for mass production. In recent decades, although volume hologram gratings have been successfully applied, the challenge of new applications still lies in the design and practical recording method [17,18]. According to the author's knowledge, no holographic radial polarization converters have been proposed.…”

“…According to the author's knowledge, no holographic radial polarization converters have been proposed. In 2018, our research group had proposed a new prism-hologram-prism sandwiched recording method for the recording of polarization-selective substrate-mode volume holograms with a large diffraction angle which can be applied [18].…”