Organic Recording Materials Polymer based recording materials are a promising area of research for the ultimate holographic storage medium. Often the physical mechanism which leads to desirable holographic characteristics is directly related to some physical property. Typically shrinkage is a problem in polymer materials because the increased index of refraction, needed to create an index grating, is the result of an increase in local density. The increase in local density causes a decrease in volume, resulting in shrinkage. If swelling were to occur, it would cause similar problems to the quality of the recorded holograms.
High sensitivity is desirable so that a shorter recording time can be used.
There are two reasons why a short recording time is desirable. First, during recording the optical setup must be completely stable. Any vibrations or unequal phase shifts between beams will cause the interference pattern to shift, decreasing the hologram quality. With a shorter recording time these problems are minimized, and the hologram quality will be better. The second reason is related to the multiplexing of many holograms in a single material.