Hologrm Recording with Highly Sensitive Photopolymer Material

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03650713
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 高分子物性・高分子材料（含機械材料）
• Research Institution: Chiba University
• Principal Investigator: KOSEKI Kenichi Chiba University, Faculty of Engineering, Research Associate, 工学部, 助手 (70092054)
• Co-Investigator(Kenkyū-buntansha): YAMAOKA Tsuguo Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (60009256)
• Project Period (FY): 1991 – 1992
• Keywords: Volume Hologram / Relief Hologram / He-Ne Laser Recording / Photopolymer / Photopolymerization / Chemically Amplified Photoresist / Squarilium Dye

Research Abstract

The photographic and holographic characteristics of photopolymer spectrally sensitized with squarilium dye(SQD) were investigated under He-Ne laser exposure. The photopolymer layr consists of four components : matrix polymer, multifunctional monomer (pentaerythritol triacrylate) or acid-activatable crosslinker (hexamethoxymethyl melamine), 2,4,6-tris(trichloromethyl)-s-stiazine(TCT) and SQD.TCT acts as a radical generator and an acid generator at the same time. When TCT was used as the photoinitiator by itself without sensitizer, the sensitivity appeared only ultraviolet wavelength shorter than 300nm. Therefore it is difficult to use it as a photo-radical or photo-acid generator of visible light imaging material. The dye has a wavelength of absorption maximum at 633nm. By combining TCT with SQD, the range of spectral sensitivity was remarkably extended toward red-light spectral region. TCT gave a radical and an acid simultaneously by electron transfer mechanism from photoexcited SQD to TCT.Lippmann hologram with a high diffraction efficiency(98%) was recorded by the photopolymerization system. Relief hologram with high diffraction efficiency(>30%) was recorded by the chemically amplified resist system. The sensitivity of hologram recording of the order of 1 mJ/cm^2 was obtained for He-Ne laser light.