Rewritable hologram recording materials with reversible photo-polymerization

聚合物的折射率变化是由光照引起的，随着温度的变化，聚合物的晶体结构也发生了变化。利用椭偏光谱法测量了材料的平均折射率变化。采用干涉法测量了空间分辨指数的变化。另一种方法是利用香豆素分子两端附着的聚合物，在光照下通过二聚化及其逆过程改变折射率和吸收光谱。

Refractive index change is induced by the light illumination in the polymer that changes crystal structure with the temperature changing process. The average refractive change of the material is measured by the Spectroscopic Ellipsometry. Space resolved index change is measured by the interferometry. In other approach, using the polymer that coumarin molecules are attached to both end, we changed the refractive index and absorption spectrum by the dimerization and its inverse process with light illumination.