Influence of some parameters on grating structure and diffraction efficiency in red-sensitive dichromated gelatin (DCG)

摘要

Dichromated gelatin with methylene blue is red sensitive. Tetramethylguanidine intensifies this red sensitivity. Such an emulsion was used to produce holographic plates to inscribe a transmission grating with a Kr$+$PLU$/-laser and to investigate some procedure and development parameters on the structure and diffraction efficiency. Ratio and concentration of prehardener, fixer, sensitizing solution, and pH-dependence were investigated. For the development, a six-step development process gave the best results. Influence of room humidity and storage time are important. The optimized process needs 3 hours from the first step to the finished hologram grating. More than 70% diffraction efficiency is possible. The coating method allows for the making of layers of different thickness and therefore volume effects can be observed.