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Optical Materials Express

Optical Materials Express

  • Editor: David J. Hagan
  • Vol. 2, Iss. 8 — Aug. 1, 2012
  • pp: 1135–1140

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Polymer-stabilized blue phase liquid crystal with a negative Kerr constant

Yan Li, Yuan Chen, Jin Yan, Yifan Liu, Jianpeng Cui, Qionghua Wang, and Shin-Tson Wu  »View Author Affiliations


Optical Materials Express, Vol. 2, Issue 8, pp. 1135-1140 (2012)
http://dx.doi.org/10.1364/OME.2.001135


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Abstract

A polymer-stabilized blue-phase liquid crystal (BPLC) with a negative Kerr constant is reported. In a voltage-on state, the double-twist BPLC molecules within the lattice cylinders are reoriented perpendicular to the applied electric field because of their negative dielectric anisotropy. As a result, the induced birefringence has a negative value, which leads to a negative Kerr constant. The negative sign of Kerr constant is experimentally validated by using a quarter-wave plate and a vertical field switching cell. Such a BPLC shows a negligible (~1%) hysteresis and fast response time (~1ms) at the room temperature, although its Kerr constant is relatively small because the employed host has a small Δε.

© 2012 OSA

1. Introduction

Blue phase liquid crystal (BPLC) [1

P. P. Crooker, “Blue phases,” in Chirality in Liquid Crystals (Springer, 2001), Chap. 7, pp. 186–222.

,2

H. S. Kitzerow, “Blue phases come of age: a review,” Proc. SPIE 7232, 723205 (2009). [CrossRef]

] is a self-assembled nano-structured composite. It is typically comprised of 90-95wt% nematic LC host and 5-10wt% chiral dopant with a high helical twisting power (HTP>100) [3

J. Yan and S. T. Wu, “Polymer-stabilized blue phase liquid crystals: a tutorial,” Opt. Mater. Express 1(8), 1527–1535 (2011). [CrossRef]

]. Most of BPLCs studied so far employ a positive dielectric anisotropy (Δε) LC host. If the LC host has a positive Δε, then the electric-field-induced birefringence Δnind, which is defined as ne(E)-no(E), will also have a positive sign, and vice versa. BPLCs with negative Δε LC hosts have been investigated since 1980s [4

G. Heppke, H. S. Kitzerow, and M. Krumrey, “Electric field induced variation of the refractive index in cholesteric blue phases,” Mol. Cryst. Liq. Cryst. Lett. 2, 59–65 (1985).

,5

G. Heppke, H. S. Kitzerow, and M. Krumrey, “Electrooptical behaviour of cholesteric blue phases with negative dielectric anisotropy,” Mol. Cryst. Liq. Cryst. Lett. 1, 117–122 (1985).

]. However, the temperature range of such a BPLC is too narrow to be practically useful. Moreover, the measured induced birefringence is easily affected by the lattice distortion and phase transition because of the soft BPLC structure. This is evidenced by the relatively slow response time, a few milliseconds instead of submillisecond, as reported in [2

H. S. Kitzerow, “Blue phases come of age: a review,” Proc. SPIE 7232, 723205 (2009). [CrossRef]

].

Another approach for obtaining negative induced birefringence (or negative Kerr constant) is to utilize Debye relaxation of a positive Δε LC host [6

Y. Li, Y. Chen, J. Sun, S. T. Wu, S. H. Liu, P. J. Hsieh, K. L. Cheng, and J. W. Shiu, “Dielectric dispersion on the Kerr constant of blue phase liquid crystals,” Appl. Phys. Lett. 99(18), 181126 (2011). [CrossRef]

]. As frequency increases, the bulky LC molecules can no longer follow the electric field so that the initially positive Kerr constant gradually decreases and eventually turns to negative. Recently, an interesting approach to obtain a negative Kerr constant with a dual frequency liquid crystal (DFLC) is demonstrated [7

S. Yabu, H. Yoshida, G. Lim, K. Kaneko, Y. Okumura, N. Uehara, H. Kikuchi, and M. Ozaki, “Dual frequency operation of a blue phase liquid crystal,” Opt. Mater. Express 1(8), 1577–1584 (2011). [CrossRef]

]. Such a BPLC exhibits an attractive feature: by switching the frequency of the applied electric field, both positive and negative Kerr constants can be realized, which results in a large refractive index change. However, to achieve a negative Δε the required operating frequency is usually over 100 kHz [7

S. Yabu, H. Yoshida, G. Lim, K. Kaneko, Y. Okumura, N. Uehara, H. Kikuchi, and M. Ozaki, “Dual frequency operation of a blue phase liquid crystal,” Opt. Mater. Express 1(8), 1577–1584 (2011). [CrossRef]

]. At such a high frequency, dielectric heating [8

C. H. Wen and S. T. Wu, “Dielectric heating effects of dual-frequency liquid crystals,” Appl. Phys. Lett. 86(23), 231104 (2005). [CrossRef]

] becomes severe, which in turn shifts the crossover frequency toward the high frequency side. Another technical issue of DFLC is its relatively small |Δε| value, because a DFLC mixture usually consists of positive Δε and negative Δε LC compounds [9

H. Xianyu, S. T. Wu, and C. L. Lin, “Dual frequency liquid crystals: a review,” Liq. Cryst. 36(6–7), 717–726 (2009). [CrossRef]

]. Small |Δε| leads to a small Kerr constant and high operation voltage [10

L. Rao, J. Yan, S. T. Wu, S. Yamamoto, and Y. Haseba, “A large Kerr constant polymer-stabilized blue phase liquid crystal,” Appl. Phys. Lett. 98(8), 081109 (2011). [CrossRef]

], which in turn causes a large hysteresis [11

L. Rao, J. Yan, S. T. Wu, Y. C. Lai, Y. H. Chiu, H. Y. Chen, C. C. Liang, C. M. Wu, P. J. Hsieh, S. H. Liu, and K. L. Cheng, “Critical Field for a Hysteresis-Free BPLC Device,” J. Display Technol. 7(12), 627–629 (2011). [CrossRef]

].

Polymer-stabilized blue phase (PSBP) [12

H. Kikuchi, M. Yokota, Y. Hisakado, H. Yang, and T. Kajiyama, “Polymer-stabilized liquid crystal blue phases,” Nat. Mater. 1(1), 64–68 (2002). [CrossRef] [PubMed]

–14

J. Yan, L. Rao, M. Jiao, Y. Li, H. C. Cheng, and S. T. Wu, “Polymer-stabilized optically isotropic liquid crystals for next-generation display and photonics applications,” J. Mater. Chem. 21(22), 7870–7877 (2011). [CrossRef]

], with the assist of polymer network, has greatly expanded the BP temperature range. It is emerging as a strong contender for next-generation display [15

Z. Ge, L. Rao, S. Gauza, and S. T. Wu, “Modeling of blue phase liquid crystal displays,” J. Display Technol. 5(7), 250–256 (2009). [CrossRef]

–18

Y. Li and S. T. Wu, “Transmissive and transflective blue-phase LCDs with enhanced protrusion electrodes,” J. Display Technol. 7(7), 359–361 (2011). [CrossRef]

] and photonic devices [19

Y. H. Lin, H. S. Chen, H. C. Lin, Y. S. Tsou, H. K. Hsu, and W. Y. Li, “Polarizer-free and fast response microlens arrays using polymer-stabilized blue phase liquid crystals,” Appl. Phys. Lett. 96(11), 113505 (2010). [CrossRef]

–23

H. Y. Liu, C. T. Wang, C. Y. Hsu, T. H. Lin, and J. H. Liu, “Optically tuneable blue phase photonic band gaps,” Appl. Phys. Lett. 96(12), 121103 (2010). [CrossRef]

]. So far, almost all the PSBPs reported in literatures employ a positive dielectric anisotropy (Δε>0) LC host, because it is easier to obtain a large, positive Δε LC compound than the corresponding negative one. As a matter of fact, BPLC hosts with Δε>190 have been reported [24

M. Wittig, N. Tanaka, D. Wilkes, M. Bremer, D. Pauluth, J. Canisius, A. Yeh, R. Yan, K. Skjonnemand, and M. Klasen-Memmer, “New materials for polymer-stabilized blue phase,” SID Int. Symp. Digest Tech. Papers 43, 25–28 (2012).

].

In this article, we report a PSBP composite with a large negative Δε (−11 at 1 kHz) LC host. The polymerization extends the BP temperature range from 8 °C to 98 °C, and therefore it enables us to study the electro-optical properties of the PSBP with a negative Kerr constant at room temperature without noticeable dielectric heating. Due to the relatively large negative Δε, the measured Kerr constant is −0.16 nm/V2. Although this value is about 10X smaller than that of a typical positive Δε BPLC, it is ~30X higher than that of BPLC employing a DFLC [7

S. Yabu, H. Yoshida, G. Lim, K. Kaneko, Y. Okumura, N. Uehara, H. Kikuchi, and M. Ozaki, “Dual frequency operation of a blue phase liquid crystal,” Opt. Mater. Express 1(8), 1577–1584 (2011). [CrossRef]

]. To validate the negative sign of Kerr constant, we develop a simple measurement method by incorporating a quarter-wave plate between the crossed polarizers. Such a polymer-stabilized BPLC with negative Kerr constant is not only of scientific interest, it can also work as a tunable negative C-plate for controlling the viewing angle of a LCD [25

L. Rao, Z. Ge, and S. T. Wu, “Viewing angle controllable displays with a blue-phase liquid crystal cell,” Opt. Express 18(3), 3143–3148 (2010). [CrossRef] [PubMed]

].

2. Theory

Macroscopically, the electric field-induced birefringence of a BPLC follows Kerr effect in the low field region [26

J. Kerr, “A new relation between electricity and light: Dielectrified media birefringent,” Philos. Mag. 50, 337–348 (1875).

,27

Z. Ge, S. Gauza, M. Jiao, H. Xianyu, and S. T. Wu, “Electro-optics of polymer-stabilized blue phase liquid crystal displays,” Appl. Phys. Lett. 94(10), 101104 (2009). [CrossRef]

]:
Δ n ind= ne(E)− no(E)=λK E2,
(1)
where λ is the wavelength, K the Kerr constant, and E the electric field amplitude. According to Gerber’s model [28

P. R. Gerber, “Electro-optical effects of a small-pitch blue-phase system,” Mol. Cryst. Liq. Cryst. 116(3–4), 197–206 (1985). [CrossRef]

], Kerr constant could be approximated by the following equation:
K≈ΔnΔε p2 λk (2π)2,
(2)
where ∆n is the birefringence, ∆ε the dielectric anisotropy, and k the elastic constant of the LC host, respectively, and p is the pitch length. For a positive Δn LC, Eq. (2) indicates that Kerr constant is not only proportional to Δε, but also has the same sign. For a polymer-stabilized BPLC with positive Δε, Kerr constant is positive and ne(E)>no(E), as Eq. (1) shows. But for a negative ∆ε LC, K should be negative and ne(E)<no(E).

3. Experiment

In experiment, we fabricated a BPLC composite using a large negative Δε nematic LC host SLC-10V513-200 (from SLICHEM, China). Its physical properties are listed as follows: Δε = −11 at f = 1 kHz, birefringence Δn = 0.147 at λ = 633 nm and ~22°C, and clearing temperature Tc = 93 °C. We mixed 84.3 wt % of the host LC, 5 wt % chiral dopant R5011 (HCCH, China) and 10.7 wt % monomers (4.7 wt % C12A and 6 wt % RM257) to form the precursor. Here, both chiral dopant and monomers are all nonpolar so that their dielectric anisotropy is negligible. The precursor was then filled into two cells. Cell 1 has IPS electrodes on the bottom substrate. The ITO (indium tin oxide) electrode width and gap are both 10 µm, and cell gap is 7.5 µm. Cell 2 is a VFS (vertical field switching) cell [29

H. C. Cheng, J. Yan, T. Ishinabe, and S. T. Wu, “Vertical field switching for blue-phase liquid crystal devices,” Appl. Phys. Lett. 98(26), 261102 (2011). [CrossRef]

] consisting of two ITO glass substrates (but without polyimide alignment layer) and has a cell gap of 10 µm.

Blue phase was observed from 61.9°C to 70°C during heating process and from 68.2°C to 57.8°C during cooling process. Both cells were cured at 61.2°C during cooling by a UV light with λ~365 nm and intensity ~2 mW/cm2 for 30 min. After UV exposure, the blue phase was stabilized with a clearing temperature Tc ~82.6°C. For benchmarking, we made another VFS cell (Cell 3) filled with JNC JC-BP01M whose host LC has a very large positive dielectric anisotropy (Δε~94) [10

L. Rao, J. Yan, S. T. Wu, S. Yamamoto, and Y. Haseba, “A large Kerr constant polymer-stabilized blue phase liquid crystal,” Appl. Phys. Lett. 98(8), 081109 (2011). [CrossRef]

].

4. Results and discussions

We observed Cell 1 (IPS) under a polarizing optical microscope with crossed polarizers. The electrode direction was oriented at 45° with respect to the transmission axes of polarizers. Figure 1 shows the microscopic textures. From Fig. 1(a), at voltage-off state (V = 0) the polymer-stabilized BPLC appears dark with some purple platelets, because the central wavelength of Bragg reflection occurs at around 390 nm. Figures 1(b) and 1(c) are with a root-mean-square voltage of 44Vrms and 60 Vrms, respectively. In the region between electrodes, the brightness is dramatically increased, while it remains dark on the electrodes. The increased transmittance between crossed polarizers indicates that some birefringence is induced in the horizontal direction. As the voltage increases, transmittance gradually increases. This phenomenon is similar to that of an IPS BPLC cell with a positive Δε LC host, but it is difficult to tell whether the induced birefringence is positive or negative. We also examined Cell 2 (VFS) under the same microscope stage and observed very similar textures at V = 0. However, as we applied a similar voltage no noticeable brightness change was observed. This is because the induced birefringence is along the longitudinal direction and the incident light experiences no phase retardation and is blocked by the crossed analyzer.

Fig. 1 (a) Microscopic image of Cell 1 under crossed polarizers at V = 0, (b) at V = 44Vrms, and (c) at V = 60Vrms; (d) Experimental setup for measuring the electro-optic properties of the VFS cells.

To further investigate the electro-optic properties of Cell 2 (VFS), we used a similar measurement method as reported in [29

H. C. Cheng, J. Yan, T. Ishinabe, and S. T. Wu, “Vertical field switching for blue-phase liquid crystal devices,” Appl. Phys. Lett. 98(26), 261102 (2011). [CrossRef]

]. The setup is shown in Fig. 1(d). A He-Ne laser beam (λ = 632.8 nm) was used as a probing light source. The VFS cell was immersed in a glass container with glycerol (n = 1.47) so that the laser beam could enter the cell at a large angle due to matched refractive index. Otherwise, the incident angle would be limited by Snell’s law. The cell was sitting on a rotary stage so that the incident angle (θ) could be controlled easily. The transmission axes of polarizer and analyzer were set at 45° and −45° with respect to the rotational axis of the cell, so that the ordinary (o) wave and extraordinary (e) wave would have the same amplitude, and the phase retardation could be extracted by the measured transmittance. A quarter-wave (QW) plate was placed after the polarizer but before the VFS cell, with its optical axis oriented at 90° to the VFS cell’s rotational axis. Therefore, the total phase retardation after passing the QW plate and VFS cell would be δ = π/2 + δVFS, where δVFS = [neff(E)-no(E)]d/sinθ, and neff(E) = [(1 + tg2θ)/(1/no(E)2 + tg2θ/ne(E)2)]1/2. For a BPLC with a positive induced birefringence (i.e., positive Kerr constant), ne(E)>neff(E)>no(E) and δVFS increases with voltage, so the total phase δ = π/2 + δVFS increases with a starting point of π/2. As a result, the transmittance sin2δ/2 under crossed polarizers should first increase with applied voltage in the low field region (0<δVFS<π/2 and π/2<δ<π). On the other hand, for a BPLC with a negative induced birefringence (i.e., negative Kerr constant), ne(E)<neff(E)<no(E) and δVFS is a negative value, which decreases with voltage. Therefore, δ = π/2 + δVFS should decrease as voltage increases and we should observe a decreased transmittance in the low field region (-π/2 <δVFS<0 and 0<δ< π/2).

To validate the above analyses, we measured the voltage-dependent transmittance (VT) curves of Cell 2 and Cell 3, and the results are plotted in Fig. 2 . Here the transmittance is normalized to that of two parallel polarizers. Since the BPLC has a relatively small negative Kerr constant, we chose a large incident angle θ = 80° in a VFS cell in order to accumulate sufficient phase retardation. The electric field frequency is 1 kHz. As expected, Cell 2 and Cell 3 exhibit an opposite transmittance change in low field region, indicating their Kerr constants are indeed with an opposite sign. The transmittance of Cell 3 (positive Δε) increases with voltage until 8Vrms and then decreases as voltage further increases. This is because the positive Δε BPLC in Cell 3 has a large Kerr constant, and the phase retardation δVFS reaches π/2 (δ = π/2 + δVFS = π) at V = 8Vrms, where peak transmittance occurs. On the contrary, the transmittance of Cell 2 (negative Δε) decreases as voltage increases and does not reach a minimum due to its relatively small Kerr constant. Ideally, at V = 0 both cells should be at 50% transmittance. But as Fig. 2 shows, there is a small displacement. This phenomenon can be explained as follows: 1) The transmittance sin2δ/2 has the largest slope near δ = π/2, therefore, even a small phase retardation deviation will be magnified. 2) In our VFS cell, the incident angle is quite large (80°). A small residual birefringence from the BPLC sample or depolarization from any optical component could lead to small phase retardation.

Fig. 2 Measured VT curves of Cell 2 and Cell 3 using the experimental setup in Fig. 1(d) with a QW plate sitting in front of the VFS cells.

Next we removed the QW plate and measured the VT curve of Cell 2 again. As shown in Fig. 3 , the transmittance peak occurs at 80Vrms and the hysteresis [30

K. M. Chen, S. Gauza, H. Xianyu, and S. T. Wu, “Hysteresis effects in blue-phase liquid crystals,” J. Display Technol. 6(8), 318–322 (2010). [CrossRef]

] (defined as ΔV/Vp, where ΔV is the voltage difference at half-maximum transmittance between forward and backward, and Vp is the peak-transmittance voltage) is quite small (~1%). The dark state of the VFS cell is not very good because of the large incident angle (80°). We used extended Kerr model [31

J. Yan, H. C. Cheng, S. Gauza, Y. Li, M. Jiao, L. Rao, and S. T. Wu, “Extended Kerr effect of polymer-stabilized blue-phase liquid crystals,” Appl. Phys. Lett. 96(7), 071105 (2010). [CrossRef]

] to fit the VT curve, and obtained Kerr constant K = −0.16 nm/V2. The small Kerr constant is mainly due to the relatively small dielectric anisotropy (Δε = −11) of the host LC.

Fig. 3 Measured VT curve of Cell 2 using the experimental setup in Fig. 1(d) without a QW plate in front of the VFS cell.

We also measured the response time (between dark state and peak-transmittance state) of Cell 2 (VFS) at the room temperature. The rise time and decay time are all about 1 ms. As the temperature increases, the response time decreases sharply, which is similar to that of positive Δε BPLC materials [10

L. Rao, J. Yan, S. T. Wu, S. Yamamoto, and Y. Haseba, “A large Kerr constant polymer-stabilized blue phase liquid crystal,” Appl. Phys. Lett. 98(8), 081109 (2011). [CrossRef]

].

5. Conclusion

We report the results of a polymer-stabilized BPLC with a negative Kerr constant, which originates from the negative Δε of the employed LC host. To experimentally prove that indeed the BPLC has a negative induced birefringence (ne<no), we incorporated a quarter-wave plate in our measurement system. Our material shows a negligible (~1%) hysteresis and fast response time (~1ms) at the room temperature, although its Kerr constant is ~10X smaller than that of a typical PSBP with a positive LC host, but this value is ~30X higher than that using a DFLC [7

S. Yabu, H. Yoshida, G. Lim, K. Kaneko, Y. Okumura, N. Uehara, H. Kikuchi, and M. Ozaki, “Dual frequency operation of a blue phase liquid crystal,” Opt. Mater. Express 1(8), 1577–1584 (2011). [CrossRef]

]. The flattened refractive index ellipsoid can be used as a tunable C-plate for controlling the viewing angle of a LCD.

Acknowledgments

The authors are indebted to ITRI (Taiwan) for financial support.

References and links

1.

P. P. Crooker, “Blue phases,” in Chirality in Liquid Crystals (Springer, 2001), Chap. 7, pp. 186–222.

2.

H. S. Kitzerow, “Blue phases come of age: a review,” Proc. SPIE 7232, 723205 (2009). [CrossRef]

3.

J. Yan and S. T. Wu, “Polymer-stabilized blue phase liquid crystals: a tutorial,” Opt. Mater. Express 1(8), 1527–1535 (2011). [CrossRef]

4.

G. Heppke, H. S. Kitzerow, and M. Krumrey, “Electric field induced variation of the refractive index in cholesteric blue phases,” Mol. Cryst. Liq. Cryst. Lett. 2, 59–65 (1985).

5.

G. Heppke, H. S. Kitzerow, and M. Krumrey, “Electrooptical behaviour of cholesteric blue phases with negative dielectric anisotropy,” Mol. Cryst. Liq. Cryst. Lett. 1, 117–122 (1985).

6.

Y. Li, Y. Chen, J. Sun, S. T. Wu, S. H. Liu, P. J. Hsieh, K. L. Cheng, and J. W. Shiu, “Dielectric dispersion on the Kerr constant of blue phase liquid crystals,” Appl. Phys. Lett. 99(18), 181126 (2011). [CrossRef]

7.

S. Yabu, H. Yoshida, G. Lim, K. Kaneko, Y. Okumura, N. Uehara, H. Kikuchi, and M. Ozaki, “Dual frequency operation of a blue phase liquid crystal,” Opt. Mater. Express 1(8), 1577–1584 (2011). [CrossRef]

8.

C. H. Wen and S. T. Wu, “Dielectric heating effects of dual-frequency liquid crystals,” Appl. Phys. Lett. 86(23), 231104 (2005). [CrossRef]

9.

H. Xianyu, S. T. Wu, and C. L. Lin, “Dual frequency liquid crystals: a review,” Liq. Cryst. 36(6–7), 717–726 (2009). [CrossRef]

10.

L. Rao, J. Yan, S. T. Wu, S. Yamamoto, and Y. Haseba, “A large Kerr constant polymer-stabilized blue phase liquid crystal,” Appl. Phys. Lett. 98(8), 081109 (2011). [CrossRef]

11.

L. Rao, J. Yan, S. T. Wu, Y. C. Lai, Y. H. Chiu, H. Y. Chen, C. C. Liang, C. M. Wu, P. J. Hsieh, S. H. Liu, and K. L. Cheng, “Critical Field for a Hysteresis-Free BPLC Device,” J. Display Technol. 7(12), 627–629 (2011). [CrossRef]

12.

H. Kikuchi, M. Yokota, Y. Hisakado, H. Yang, and T. Kajiyama, “Polymer-stabilized liquid crystal blue phases,” Nat. Mater. 1(1), 64–68 (2002). [CrossRef] [PubMed]

13.

Y. Haseba, H. Kikuchi, T. Nagamura, and T. Kajiyama, “Large electro-optic Kerr effect in nanostructured chiral liquid-crystal composites over a wide temperature range,” Adv. Mater. 17(19), 2311–2315 (2005). [CrossRef]

14.

J. Yan, L. Rao, M. Jiao, Y. Li, H. C. Cheng, and S. T. Wu, “Polymer-stabilized optically isotropic liquid crystals for next-generation display and photonics applications,” J. Mater. Chem. 21(22), 7870–7877 (2011). [CrossRef]

15.

Z. Ge, L. Rao, S. Gauza, and S. T. Wu, “Modeling of blue phase liquid crystal displays,” J. Display Technol. 5(7), 250–256 (2009). [CrossRef]

16.

M. Jiao, Y. Li, and S. T. Wu, “Low voltage and high transmittance blue-phase liquid crystal displays with corrugated electrodes,” Appl. Phys. Lett. 96(1), 011102 (2010). [CrossRef]

17.

Y. Li, M. Jiao, and S. T. Wu, “Transflective display using a polymer-stabilized blue-phase liquid crystal,” Opt. Express 18(16), 16486–16491 (2010). [CrossRef] [PubMed]

18.

Y. Li and S. T. Wu, “Transmissive and transflective blue-phase LCDs with enhanced protrusion electrodes,” J. Display Technol. 7(7), 359–361 (2011). [CrossRef]

19.

Y. H. Lin, H. S. Chen, H. C. Lin, Y. S. Tsou, H. K. Hsu, and W. Y. Li, “Polarizer-free and fast response microlens arrays using polymer-stabilized blue phase liquid crystals,” Appl. Phys. Lett. 96(11), 113505 (2010). [CrossRef]

20.

J. Yan, Y. Li, and S. T. Wu, “High-efficiency and fast-response tunable phase grating using a blue phase liquid crystal,” Opt. Lett. 36(8), 1404–1406 (2011). [CrossRef] [PubMed]

21.

Y. Li and S. T. Wu, “Polarization independent adaptive microlens with a blue-phase liquid crystal,” Opt. Express 19(9), 8045–8050 (2011). [CrossRef] [PubMed]

22.

Y. Li, Y. Liu, Q. Li, and S. T. Wu, “Polarization independent blue-phase liquid crystal cylindrical lens with a resistive film,” Appl. Opt. 51(14), 2568–2572 (2012). [CrossRef] [PubMed]

23.

H. Y. Liu, C. T. Wang, C. Y. Hsu, T. H. Lin, and J. H. Liu, “Optically tuneable blue phase photonic band gaps,” Appl. Phys. Lett. 96(12), 121103 (2010). [CrossRef]

24.

M. Wittig, N. Tanaka, D. Wilkes, M. Bremer, D. Pauluth, J. Canisius, A. Yeh, R. Yan, K. Skjonnemand, and M. Klasen-Memmer, “New materials for polymer-stabilized blue phase,” SID Int. Symp. Digest Tech. Papers 43, 25–28 (2012).

25.

L. Rao, Z. Ge, and S. T. Wu, “Viewing angle controllable displays with a blue-phase liquid crystal cell,” Opt. Express 18(3), 3143–3148 (2010). [CrossRef] [PubMed]

26.

J. Kerr, “A new relation between electricity and light: Dielectrified media birefringent,” Philos. Mag. 50, 337–348 (1875).

27.

Z. Ge, S. Gauza, M. Jiao, H. Xianyu, and S. T. Wu, “Electro-optics of polymer-stabilized blue phase liquid crystal displays,” Appl. Phys. Lett. 94(10), 101104 (2009). [CrossRef]

28.

P. R. Gerber, “Electro-optical effects of a small-pitch blue-phase system,” Mol. Cryst. Liq. Cryst. 116(3–4), 197–206 (1985). [CrossRef]

29.

H. C. Cheng, J. Yan, T. Ishinabe, and S. T. Wu, “Vertical field switching for blue-phase liquid crystal devices,” Appl. Phys. Lett. 98(26), 261102 (2011). [CrossRef]

30.

K. M. Chen, S. Gauza, H. Xianyu, and S. T. Wu, “Hysteresis effects in blue-phase liquid crystals,” J. Display Technol. 6(8), 318–322 (2010). [CrossRef]

31.

J. Yan, H. C. Cheng, S. Gauza, Y. Li, M. Jiao, L. Rao, and S. T. Wu, “Extended Kerr effect of polymer-stabilized blue-phase liquid crystals,” Appl. Phys. Lett. 96(7), 071105 (2010). [CrossRef]

OCIS Codes
(160.3710) Materials : Liquid crystals
(160.5470) Materials : Polymers

ToC Category:
Liquid Crystals

History
Original Manuscript: July 18, 2012
Manuscript Accepted: July 24, 2012
Published: July 26, 2012

Citation
Yan Li, Yuan Chen, Jin Yan, Yifan Liu, Jianpeng Cui, Qionghua Wang, and Shin-Tson Wu, "Polymer-stabilized blue phase liquid crystal with a negative Kerr constant," Opt. Mater. Express 2, 1135-1140 (2012)
http://www.opticsinfobase.org/ome/abstract.cfm?URI=ome-2-8-1135


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References

  1. P. P. Crooker, “Blue phases,” in Chirality in Liquid Crystals (Springer, 2001), Chap. 7, pp. 186–222.
  2. H. S. Kitzerow, “Blue phases come of age: a review,” Proc. SPIE7232, 723205 (2009). [CrossRef]
  3. J. Yan and S. T. Wu, “Polymer-stabilized blue phase liquid crystals: a tutorial,” Opt. Mater. Express1(8), 1527–1535 (2011). [CrossRef]
  4. G. Heppke, H. S. Kitzerow, and M. Krumrey, “Electric field induced variation of the refractive index in cholesteric blue phases,” Mol. Cryst. Liq. Cryst. Lett.2, 59–65 (1985).
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