Institute Of Physical And Chemical Technology Makes New Progress in The Research Of Holographic Photopolymers

In recent years, with the development of near-eye display technology, augmented reality (AR) technology, which can realize the function of "virtual-reality fusion", is becoming an important development direction of the new generation of display technology, whose core optical components are optical couplers. The holographic optical waveguide prepared by photopolymeric volume holographic grating (VHG) as the coupling element has the advantages of small size, light weight, clear imaging, and flexible design, and is receiving a lot of attention in the field of AR research and development. In order to achieve the preparation of high performance transparent body holographic gratings, the refractive index modulation (∆n) of the photopolymer must be at least higher than 0.02. However, only a very small amount of holographic photopolymer can achieve this requirement in the work reported in the literature so far. The material has become the biggest technical bottleneck limiting the development of this field.
Through material innovation and formulation optimization, a series of acrylate monomers containing carbazole groups with high refractive index were designed and synthesized by the New Functional Polymers Group of the Institute of Physical and Chemical Technology, Chinese Academy of Sciences and the Center for Applied Laser Research, and high-performance holographic photopolymers were developed and used to prepare transparent holographic gratings with △n as high as 0.046 (see Figure 1, resolution: 3250 line/mm; diffraction efficiency: 95.5 mm). mm; diffraction efficiency: 95.16%, 400-800 nm transmittance: 96.62%). In addition, the reflective holograms recorded with this material not only have high resolution, but also have excellent optical transparency. This research has laid a solid material foundation for the subsequent development of high-performance transparent holographic waveguides.
The research results were recently published as High refractive index monomers for improving the holographic recording performance of two-stage photopolymers in ACS The first author of the paper is Bin Guo, a PhD student in the Institute of Physics and Chemistry, and the corresponding authors are Yong Bi and Yuxia Zhao.