Holographic recording media based on oligomers and co-oligomers with organic dye additives

Abstract

We have created holographic recording media based on films of carbazolyl-, fluorenyl-, naphthyl-, and anthracenyl-containing oligomers and co-oligomers in which an intraionic organic dye is used as the sensitizer. We have established that the photoconductivity of the films and the photosensitivity of the recording media are higher in the case of co-oligomers with different donor moieties. We conclude that in the films of co-oligomers with different donor moieties in the "end" groups of the polymer chain, there is reduced probability of formation of excimers, which are centers for capturing photogenerated charge carriers, and therefore the photoconductivity of the film increases.Introduction. The photothermoplastic (PTP) method for recording optical information is used for archiving information, preserving valuable documents, and artistic holography, and also is very suitable for holographic interferometry and nondestructive testing due to the high resolution and fast dry development of holograms without changing the position of the recording medium [1,2]. The recording medium is made in the form of a thin oligomeric film deposited on an electrically conducting undercoat. Generally such films are an oligomer-based composite (oligomer composite in the following) with hole type conductivity and containing organic sensitizer additives [3]. The sensitizers provide absorption of light and photogeneration of charge carriers at the emission wavelength of the laser used, and sometimes also electron transport [2]. Organic dyes are also used as sensitizers [4]. In this work, we have carried out a comparative study of the photoconductivity of oligomer composite films based on carbazolyl-, fluorenyl-, naphthyl-, and anthracenyl-containing oligomers and co-oligomers, in which an intraionic organic dye is used as light absorption centers and centers for photogeneration of charge carriers; we have also investigated the basic informationrelated characteristics of holographic recording media based on these oligomer composites for the photothermoplastic method of recording holograms.The Experiment. We studied films of the oligomers PEPC, OGF, OAGE and the co-oligomers coo-FGE-AGE, coo-AGE-β-NGE with the bipolar squarylium dye SQ:

Reversible holographic recording media based on polymeric composites and their use in energy-saving technologies

“…For example, in [27] and [28], N. Davidenko and A. Ishchenko found that for squarylium dye 1, the energy difference between HOMOs of the carbazolyl fragment of the polymer and the dye was negative. However, it had good photosensitizing properties in carbazole-containing polymers films [5,[27][28][29]. The enquiry is that the dye 1 already forms aggregates at a concentration of 0.1 wt.% in GCBE [8], and these aggregates can photogenerate and transport both holes and electrons.…”