重铬酸盐明胶(DCG)是一种重要的全息记录材料,它有高的衍射率和低的噪声,其衍射率之高几乎可接近理论值。它的主要缺点是光敏性差,对波长大于540nm的尤基本上不感光,加入一些染料可使其感光区扩大到红光(633nm)。本文讨论了用亚甲基兰敏化重铬酸盐明胶扩大到红光区的方法,用He—Ne激光得到衍射率为80%的全息图。 Dichromated gelatin (DCG) is an important holographic recording material, which has high diffraction rate and low noise, and its diffraction rate is almost close to the theoretical value. Its main disadvantage is the poor photosensitivity, especially for wavelengths greater than 540nm is not sensible, adding some dye can make its photosensitive area expanded to red (633nm). This article discusses a method of expanding methylene blue to the red region with a dichromated gelatin and obtaining a hologram with a diffraction rate of 80% using a He-Ne laser.