Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples Part I: Experiment

Abstract

Experimental research into changes of the optical thickness of phenanthrenequinone-doped polymethyl methacrylate samples in the process of irradiation by a 473 nm laser is presented. It was demonstrated that heating-induced reversible changes lead to a decrease in the optical thickness. The temperature coefficient of the relative changes of the optical thickness was measured to be -1.40×10 К, which matches the data published by other authors. It is also established that the irreversible changes induced by the photochemical transformation lead to an increase in the optical thickness outside of the absorption band of the samples (λ>530 nm), where the relative change of which at λ=532 nm is +3.7×10. It was demonstrated that the reversible and irreversible changes do not compensate for each other in the process of sample exposure.

Угловая Селективность Амплитудно-Фазовых Голограммных Решеток В Полимерном Материале С Фенантренхиноном

“…Такие спектральные изменения вносят вклад в формирование голограмм (сформированные за их счет решетки рассматриваются как своего рода скрытое изображение), но основной интерес полимерные мате-риалы с ФХ представляют благодаря следующему за записью скрытого изображения проявлению (или усиле- нию), обусловленному диффузией непрореагировавших молекул ФХ, а происходящая при записи фотохимиче-ская реакция ценна не столько обесцвечиванием, сколь-ко связыванием ее продукта с полимерными цепями. Интересно, что сдвиг поглощения в коротковолновую область сопровождается не снижением, а увеличением показателя преломления [11], что было недавно подтвер-ждено с использованием метода цифровой интерферо-метрии [17].…”

Significant Enhancement of the Polarization Holographic Performance of Photopolymeric Materials by Introducing Graphene Oxide

“…Low polarization sensitivity is mainly induced by low saturation solubility of the photosensitizer phenanthraquinone (PQ) dissolved in methyl methacrylate (MMA) monomers and low intermolecular diffusing ability. 39 To enhance the saturation solubility of PQ and the holographic properties of composite materials, various approaches have been proposed, such as introducing comonomer or nanoscale components into MMA monomers. Introducing a suitable comonomer to increase the saturation concentration of the photosensitizer PQ 40 or introducing nanoparticles 41,42 (such as Al and SiO 2 ) has been a common strategy to enhance the polarization recording diffraction efficiency and refractive index modulation of PQ/PMMA photopolymer materials.…”

“…Large-scale application of PQ/PMMA functional materials in data storage, however, is hindered by their low polarization recording diffraction efficiency and low polarization sensitivity. Low polarization sensitivity is mainly induced by low saturation solubility of the photosensitizer phenanthraquinone (PQ) dissolved in methyl methacrylate (MMA) monomers and low intermolecular diffusing ability . To enhance the saturation solubility of PQ and the holographic properties of composite materials, various approaches have been proposed, such as introducing comonomer or nanoscale components into MMA monomers.…”

SiO2 NPs-PQ/PMMA Photopolymer Material Doped with a High-Concentration Photosensitizer for Holographic Storage

“…PQ (phenanthrenequinone) is sensitive to light and often used as a holographic storage material photosensitizer. PQ/PMMA (phenanthrenequinone-doped poly(methyl methacrylate)) photopolymer has polarization sensitivity, controllable thickness, good optical quality, and low shrinkage (contraction coefficient < 10 −5 ), all of which make it suitable as a holographic storage material for multidimensional storage [2][3][4]. However, due to the low PQ saturation concentration dissolved in MMA and to the poor photosensitivity associated with a limited quantum of PQ molecular reactions [5], PQ/PMMA is unsatisfactory regarding diffraction efficiency and polarization sensitivity.…”