High contrast switching of distributed-feedback lasing in dye-doped H-PDLC transmission grating structures

Hsiao, Vincent K. S.; Lü, Changgui; He, Guang S.; Pan, Michael; Cartwright, Alexander N.; Prasad, Paras N.; Jakubiak, Rachel; Vaia, Richard A.; Bunning, Timothy J.

doi:10.1364/opex.13.003787

Cited by 68 publications

(46 citation statements)

References 17 publications

(21 reference statements)

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“…On the last place we have evaluated a photopolymer with dispersed liquid crystal molecules, H-PDLC [23][24][25][26][27] DOEs in the low spatial frequency range. Nowadays new components have been included in the standard formulation of classical photopolymer systems to arise unexpected properties, some examples of these components are nano-particles or dispersed liquid crystal molecules (LC), by combining polymers and dispersed liquid crystals a new spectrum of interesting applications was opened.…”

Section: Introductionmentioning

confidence: 99%

“…The opportunity to design new switchable or tunable holographic displays due to phase separation between photopolymer and LC has attracted great attention. For example, the ability to control the diffraction efficiency of holographic optical elements by applying an electric field leads to the possibility of using holographic optical elements in dynamic applications for agile beam steering, nonlinear optics and optical switching devices [23][24][25]. This family of polymers is known as H-PDLC.…”

Section: Introductionmentioning

confidence: 99%

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Characterization and comparison of different photopolymers for low spatial frequency recording

et al. 2015

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a b s t r a c tFree-radical photopolymer materials can be fabricated using a wide range of monomers, binders, dyes, etc. It was shown that in some photopolymers the surface and the internal diffusion for acrylamide materials are very different and also it was demonstrated the viability of acrylamide materials to achieve 2p phase depth for low spatial diffractive optical elements. Building on the work developed previously, in this paper, a characterization and a comparison is carried out for three different photopolymers: crosslinked acrylamide based photopolymers, a biophotopol and an H-PDLC material. We have measured the motion of the components inside the material and through the surface using a new index matching component and through the surface. We have studied the introduction of different crosslinkers in order to increase the refractive index modulation and to reduce the thickness required to achieve a phase depth higher than 2p in the diffraction optical elements.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization and comparison of different photopolymers for low spatial frequency recording

et al. 2015

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“…Subsequently, Bunning and coworkers combined the optical holographic technique and PDLC materials to produce holographic polymer dispersed liquid crystals (H-PDLCs) materials to fabricate transmission or reflection gratings in a single step process [4–6]. H-PDLCs have potential application in display systems, electro-optical filters, free space optical switches, and photonic crystal switchable lasers [7–14]. In the standard H-PDLC system used for electrically switchable gratings, the pre-polymer mixture contains a photoinitiator/coinitiator, monomer, and LC.…”

Section: Introductionmentioning

confidence: 99%

Influence of non-reactive solvent on optical performance, photopolymerization kinetics and morphology of nanoporous polymer gratings

Hsiao¹,

White²,

Cartwright³

et al. 2010

European Polymer Journal

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A study of nanoporous polymer gratings, with controllable nanostructured porosity, as a function of grating performance, photopolymerization kinetics and morphology is presented. Modifying the standard holographic polymer dispersed liquid crystal (H-PDLC) system, by including a non-reactive solvent, results in a layered, nanoporous morphology and produces reflective optical elements with excellent optical performance of broadband reflection. The addition of the non-reactive solvent in the pre-polymer mixture results in a morphology typified by void/polymer layer-by-layer structures if sufficient optical energy is used during the holographic writing process. The duration and intensity of optical exposure necessary to form well-aligned nanoporous structures can only be obtained in the modified system by (a) illumination under longer time of holographic interference patterning (30 min) or (b) illumination under very short time of holographic interference patterning (30 s) and followed by post-curing using homogeneous optical exposure for 60 min. Comparatively, a typical H-PDLC is formed in less than 1 min. To further understand the differences in the formation of these two analogous materials, the temporal dynamics of the photoinitiation and polymerization (propagation) kinetics were examined. It is shown herein that the writing exposure gives a cross-linked polymer network that is denser in the bright regions. With 60% (or even 45%) acrylate conversion, almost no free monomer would be left after the writing. Continued exposure serves primarily to add cross-links. This has the tendency to collapse the network, especially the less dense portions, which in effect get glued down to the more dense parts. To the extent that the solvent increases the mobility of the polymer network, this process will be aided. Equally important, the size of the periodic nanopores can be varied from 10 to 50 nm by controlling either the LC concentration in the pre-polymer mixture or by controlling the time of the homogeneous post-cure.

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“…13 We can control the parameters of the active layer (as the gain medium and the waveguide core layer) and the HPDLC grating layer (as the feedback layer) separately to adjust the properties of the lasing output for the device. These two values of index are very close and the typical difference 16 can be as low as 10 À5 . The alternating layers of the polymer and the phase separated LC are formed corresponding to the interference patterns.…”

Section: Introductionmentioning

confidence: 71%

Enhancement of pump efficiency for an organic distributed feedback laser based on a holographic polymer dispersed liquid crystal as an external light feedback layer

Liu

Zhang

et al. 2015

J. Mater. Chem. C

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We report a low threshold, high energy conversion organic distributed feedback (DFB) laser based on a holographic polymer dispersed liquid crystal (HPDLC) grating as an external light feedback layer, specifically, by adopting an acrylate-based monomer with low functionality and a rubbed polyimide (PI) alignment layer. In such configuration, the phase separated LCs were aligned along the preferred direction, which gave an increased refractive index difference between the LC and the polymer, so it can provide better light feedback in the HPDLC layer. The pump efficiency for the laser, such as lasing output threshold and conversion efficiency, can be enhanced. The light loss, diffraction efficiency and driving voltage were also investigated for the HPDLC structures to identify the effects of the rubbing layer and monomer functionality. Fig. 7 Lasing output intensity as a function of pump intensity for the DFB laser: (a) a1, (b) a2, (c) b1 and (d) b2. The insets show the corresponding lasing spectra, respectively.

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High contrast switching of distributed-feedback lasing in dye-doped H-PDLC transmission grating structures

Cited by 68 publications

References 17 publications

Characterization and comparison of different photopolymers for low spatial frequency recording

Characterization and comparison of different photopolymers for low spatial frequency recording

Influence of non-reactive solvent on optical performance, photopolymerization kinetics and morphology of nanoporous polymer gratings

Enhancement of pump efficiency for an organic distributed feedback laser based on a holographic polymer dispersed liquid crystal as an external light feedback layer

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