Photoinduced anisotropy in rigid dye solutions for transient polarization holography

The characteristics of rigid solutions of organic dyes suitable for holographic recording-fluorescein/orthoboric acid, methyl red/polymethylmetacrylate, and methyl orange/polyvinylalcohol-are investigated. All of the three systems allow real-time recording and do not exhibit fatigue up to more than 10⁴cycles of recording erasure. The system fluorescein/orthoboric acid possesses a faster response time than the other two systems-around 0.1 s. The phase character of the recording in the system methyl orange/polyvinylalcohol explains the high diffraction efficiency-up to 35 percent-in polarization holographic recording. New experimental results on the kinetics of the photoinduced anisotropy are presented and the mechanisms which could possibly speed up the processes, repeated periodically, are discussed.