Quickly Updatable Hologram Images Using Poly(N-vinyl Carbazole) (PVCz) Photorefractive Polymer Composite

Abstract

Quickly updatable hologram images using photorefractive (PR) polymer composite based on poly(N-vinyl carbazole) (PVCz) is presented. PVCz is one of the pioneer materials of photoconductive polymers. PR polymer composite consists of 44 wt % of PVCz, 35 wt % of 4-azacycloheptylbenzylidene-malonitrile (7-DCST) as a nonlinear optical dye, 20 wt % of carbazolylethylpropionate (CzEPA) as a photoconductive plasticizer and 1 wt % of 2,4,7-trinitro-9-fluorenone (TNF) as a sensitizer. PR composite gives high diffraction efficiency of 68% at E = 45 V μm−1. Response speed of optical diffraction is the key parameter for real-time 3D holographic display. The key parameter for obtaining quickly updatable holographic images is to control the glass transition temperature lower enough to enhance chromophore orientation. Object image of the reflected coin surface recorded with reference beam at 532 nm (green beam) in the PR polymer composite is simultaneously reconstructed using a red probe beam at 642 nm. Instead of using a coin object, an object image produced by a computer was displayed on a spatial light modulator (SLM) and used for the hologram. The reflected object beam from an SLM was interfered with a reference beam on PR polymer composite to record a hologram and simultaneously reconstructed by a red probe beam.

Современное Состояние Разработки Светочувствительных Сред Для Голографии (Обзор)

“…Раз-работаны слои с чувствительностью в ИК спектраль-ном диапазоне, в том числе к импульсному лазерному излучению с частотой 100 Гц. Хорошими свойствами обладает поливинилкарбазол (ПВК) и его производ-ные [176]. Однако среды на их основе характеризуются низкой подвижностью дырок и высокой температурой стеклования (T g > 200…”

Recent Progress in Updatable Holographic 3D Display Systems Using Monolithic Organic Compounds

“…Last two years, we have developed updatable holographic display systems using photorefractive polymer devices [4][5][6][7] and monolithic organic compound of 3-[(4-nitrophenyl)azo]-9H-carbazole-9-ethanol (NACzE) dispersed film device [8,9]. For photorefractive polymer devices, millisecond order holographic response can be achieved [10], which exceeds the video rate of 30 frames/s.…”

Molecular design of photorefractive polymers

“…127 The authors also reconstructed an updatable hologram of a coin and a 2D hologram of an object image from a special light modulator using a PVK-based PR polymer composite of PVK/7-DCST/CzEPA/TNF (44/35/20/1 by wt.). 91 Using the same PR polymer device, they reconstructed a dynamic 2D hologram with an object image that was supplied from a spatial light modulator at a refresh time of 1 s using the same PVK PR device, 129 and a 50 ms response time using a PDAS-based PR composite of PDAS/FDSCT/ECZ/PCBM (44/35/20/1 by wt.). 62,63 Video-rate updatable hologram imaging was successfully demonstrated on a PDASbased PR composite because of the higher hole mobility of PDAS, which was in the order of 10 −4 -10 −3 cm 2 V −1 s −1 .…”

“…Figure 8 summarizes the commonly used plasticizers. In PR polymers, photoconductive plasticizers such as ECZ, 15,39,44,62,63 carbazoylethylpropionate (CzEPA), 44,52,91 TPA, 62,63 2,4,6-trimethylphenyl-diphenylamine (TAA) 41,42 and (4-(diphenylamino)phenyl)methanol (TPAOH) 64 have been commonly used. Photoconductive plasticizers with long alkyl chains, such as 9-(2-ethylhexyl)carbazole (EHCz), 92 have also been used.…”