Electro-optical switching of liquid crystal diffraction gratings by using surface relief effect in the photopolymer

Kotakonda, Pavani; Naydenova, Izabela; Martin, Suzanne; Jallapuram, Raghavendra; Howard, Robert Glenn; Toal, Vincent

doi:10.1016/j.optcom.2007.01.054

Cited by 16 publications

(12 citation statements)

References 20 publications

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“…It is important to note that this shrinkage value exceeds the 0.5% defined as the upper limit for commercial viablility of a holographic recording medium [15,16]. Nevertheless, these obtained photoinduced surface reliefs can be used to align liquid crystals [29,30].…”

Section: A Layers Without Crosslinkermentioning

confidence: 94%

Analysis of PVA/AA based photopolymers at the zero spatial frequency limit using interferometric methods

et al. 2008

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One of the problems associated with photopolymers as optical recording media is the thickness variation during the recording process. Different values of shrinkages or swelling are reported in the literature for photopolymers. Furthermore, these variations depend on the spatial frequencies of the gratings stored in the materials. Thickness variations can be measured using different methods: studying the deviation from the Bragg's angle for nonslanted gratings, using MicroXAM S/N 8038 interferometer, or by the thermomechanical analysis experiments. In a previous paper, we began the characterization of the properties of a polyvinyl alcohol/acrylamide based photopolymer at the lowest end of recorded spatial frequencies. In this work, we continue analyzing the thickness variations of these materials using a reflection interferometer. With this technique we are able to obtain the variations of the layers refractive index and, therefore, a direct estimation of the polymer refractive index.

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Section: A Layers Without Crosslinkermentioning

confidence: 94%

Analysis of PVA/AA based photopolymers at the zero spatial frequency limit using interferometric methods

et al. 2008

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“…Self-processing photopolymers are attractive materials for the production of easily fabricated holographic optical elements [1], for holographic data storage [2][3][4], the fabrication of switchable electro-optical devices [5] and the design of non-destructive optical test systems [6,7]. Besides the advantage of being self-developing, photopolymers can have high sensitivity, large dynamic range, good optical properties, low cost and are easy to prepare.…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopy for the characterization of the polymerization rate in an acrylamide-based photopolymer

Jallapuram¹,

Naydenova²,

Byrne³

et al. 2008

Appl. Opt.

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Recommended Citation Raghavendra, R. et al. (2008) Raman spectroscopy for the characterization of the polymerization rate in an acrylamide-based photopolymer. Applied Optics, Vol. 47, no. 2, pp. 206-212. doi:10.1364 corresponding to carbon-carbon double bond of methylenebisacrylamide using Raman spectroscopy. To study the dependence of the polymerization rate on intensity and to find the dependence parameter, the polymerization rate constant was measured at different intensities.A comparison with a commercially available photopolymer shows that the polymerization rate in this photopolymer is much faster.

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“…The DE after filling was measured to be 0.4% for E49 LCs and 0.15% for E7 LCs. The decrease in the DE could be explained by the fact the refractive index difference between polymer and LCs is smaller than the refractive index difference between polymer and air [13]. The DE values for E7 LC gratings were less than those for E49 LC gratings which could be explained by a higher difference between the average refractive index of E49 LCs and that of the photopolymer.…”

Section: Switchable Lc Diffraction Gratingsmentioning

confidence: 91%

“…Extensive investigation of the dependence of the photoinduced surface relief gratings on physical and recording parameters was reported earlier [11,12]. Switchable LC diffraction gratings were successfully fabricated by filling the surface relief gratings of spatial frequency 70 lines/mm with E49 LCs and the switching behaviour was demonstrated [13]. In this paper, we report a comparison between the behaviour of the switchable diffraction gratings using E7 (n e = 1.74, n o = 1.52) and E49 (n e = 1.79, n o = 1.53) LCs from Merck and the switching behaviour was demonstrated in each case.…”

Section: Introductionmentioning

confidence: 88%

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Fabrication of switchable liquid crystal devices using surface relief gratings in photopolymer

Kotakonda¹,

Naydenova²,

Howard³

et al. 2007

J Mater Sci: Mater Electron

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Holographically recorded surface relief gratings in dry, self-developing acrylamide based photopolymer were used to fabricate two types of switchable liquid crystal (LC) device. One is an electrically switchable LC diffraction grating and the other is an electrically switchable polarization rotator. The electrically switchable diffraction grating was characterized by measuring the dependence of the intensity in the first diffracted order on the applied electric field. The polarization rotator was characterized by studying the influence of the applied electric field on the twist angle and the variation of intensity in the zero and the first orders of diffraction.

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Electro-optical switching of liquid crystal diffraction gratings by using surface relief effect in the photopolymer

Cited by 16 publications

References 20 publications

Analysis of PVA/AA based photopolymers at the zero spatial frequency limit using interferometric methods

Analysis of PVA/AA based photopolymers at the zero spatial frequency limit using interferometric methods

Raman spectroscopy for the characterization of the polymerization rate in an acrylamide-based photopolymer

Fabrication of switchable liquid crystal devices using surface relief gratings in photopolymer

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