Gallego S, Ortuño M, Neipp C, Márquez A, Beléndez A, Pascual I, Kelly J, Sheridan J
Opt Express. 2005 Mar 21;13(6):1939-47. doi: 10.1364/opex.13.001939.
In recent years the interest in thick holographic recording materials for storage applications has increased. In particular, photopolymers are interesting materials for obtaining inexpensive thick dry layers with low noise and high diffraction efficiencies. Nonetheless, as will be demonstrated in this work, the attenuation in depth of light during the recording limits dramatically the effective optical thickness of the material. This effect must be taken into account whenever thick diffraction gratings are recorded in photopolymer materials. In this work the differences between optical and physical thickness are analyzed, applying a method based on the Rigorous Coupled Wave Theory and taking into account the attenuation in depth of the refractive index profile. By doing this the maximum optical thickness that can be achieved can be calculated. When the effective thickness is known, then the real storage capacity of the material can be obtained.
近年来，用于存储应用的厚全息记录材料的关注度有所增加。特别是，光聚合物是获得具有低噪声和高衍射效率的廉价厚干层的有趣材料。然而，正如本文将证明的那样，记录过程中光在深度上的衰减极大地限制了材料的有效光学厚度。每当在光聚合物材料中记录厚衍射光栅时，都必须考虑这种效应。在这项工作中，分析了光学厚度和物理厚度之间的差异，应用了一种基于严格耦合波理论的方法，并考虑了折射率分布在深度上的衰减。通过这样做，可以计算出可以实现的最大光学厚度。当有效厚度已知时，就可以获得材料的实际存储容量。
