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Articles 1 - 6 of 6
Full-Text Articles in Physics
Digital Integral Cloaking, Joseph S. Choi, John C. Howell
Digital Integral Cloaking, Joseph S. Choi, John C. Howell
Mathematics, Physics, and Computer Science Faculty Articles and Research
Toward the goal of achieving broadband and omnidirectional invisibility, we propose a method for practical invisibility cloaking. We call this “digital cloaking,” where space, angle, spectrum, and phase are discretized. Experimentally, we demonstrate a two-dimensional (2D) planar, ray optics, digital cloak by using lenticular lenses, similar to “integral imaging” for three-dimensional (3D) displays. Theoretically, this can be extended to a good approximation of an “ideal” 3D cloak. With continuing improvements in commercial digital technology, the resolution limitations of a digital cloak can be minimized.
Azimuthal Dependence Of Switching Field Strength For Nematic Liquid Crystal Bistability On Patterned Alignment Layers, Jun-Ichi Niitsuma, Makoto Yoneya, Hiroshi Yokoyama
Azimuthal Dependence Of Switching Field Strength For Nematic Liquid Crystal Bistability On Patterned Alignment Layers, Jun-Ichi Niitsuma, Makoto Yoneya, Hiroshi Yokoyama
Hiroshi Yokoyama
We investigate the azimuthal dependence of the switching field strength for nematic liquid crystal bistability on patterned alignment layers to determine the validity of a switching theory proposed by Kim et al. [Appl. Phys. Lett. 78, 3055 (2001)] and to evaluate higher-order azimuthal anchoring coefficients. Director behavior during switching is described in detail for general azimuthal directions of an applied electric field and the experimental results are explained on the basis of the theory. We obtain azimuthal anchoring coefficients up to the second higher-order term in an expansion of the anchoring energy function. Detailed analysis of the director behavior reveals …
Universal Off-Axis Light Transmission Properties Of The Bright State In Perfectly Compensated Liquid Crystal Devices, Yong-Kyu Jang, Philip J. Bos
Universal Off-Axis Light Transmission Properties Of The Bright State In Perfectly Compensated Liquid Crystal Devices, Yong-Kyu Jang, Philip J. Bos
Philip J. Bos
We studied the off-axis light transmission characteristics of the bright state of common liquid crystal device modes. The dark state of these device modes is optically compensated to have minimum light transmittance at all angles. Our research shows there is an unexpected universal shape of the off-axis light transmission value in its bright state, regardless of what liquid crystal mode is used. To understand this surprising fact, we consider simple dark and bright state models in terms of phase retardation and transmittance.
Thermally, Photochemically And Electrically Switchable Reflection Colors From Self-Organized Chiral Bent-Core Liquid Crystals, Quan Li, Manoj Mathews, Rafael S. Zola, Deng-Ke Yang
Thermally, Photochemically And Electrically Switchable Reflection Colors From Self-Organized Chiral Bent-Core Liquid Crystals, Quan Li, Manoj Mathews, Rafael S. Zola, Deng-Ke Yang
Quan Li
We report the synthesis and characterization of two new chiral 1,3-phenylene based five ring bent-core mesogens that combine the unique electro-optic characteristics of banana-shaped molecules with chiroptic properties. Azobenzene moiety incorporated as a linking unit in one of the rigid arms renders trans cis isomerization property to the molecules while chirality is introduced by tethering chiral aliphatic terminal chains. Both compounds can self-organize into helical superstructure, i.e. cholesteric mesophase, which can selectively reflect light. The novelty of the helical self-organized superstructure reported here lies in its low molecular weight single component molecular system that is truly multifunctional so that the …
Up-Conversion In Rare-Earth Doped Micro-Particles Applied To New Emissive 2d Dislays, Anne Milliez
Up-Conversion In Rare-Earth Doped Micro-Particles Applied To New Emissive 2d Dislays, Anne Milliez
Electronic Theses and Dissertations
Up-conversion (UC) in rare-earth co-doped fluorides to convert diode laser light in the near infrared to red, green and blue visible light is applied to make possible high performance emissive displays. The infrared-to-visible UC in the materials we study is a sequential form of non-linear two photon absorption in which a strong absorbing constituent absorbs two low energy photons and transfers this energy to another constituent which emits visible light. Some of the UC emitters' most appealing characteristics for displays are: a wide color gamut with very saturated colors, very high brightness operation without damage to the emitters, long lifetimes …
Light Propagation In Variable-Refractive-Index Materials With Liquid-Crystal-Infiltrated Microcavities, Bin Wang, Philip Bos, Charles D. Hoke
Light Propagation In Variable-Refractive-Index Materials With Liquid-Crystal-Infiltrated Microcavities, Bin Wang, Philip Bos, Charles D. Hoke
Philip J. Bos
A liquid-crystal-infiltrated microcavity structure is proposed as a variable-refractive-index material. It has the advantages over previously considered nanostructured materials of having a larger phase-angle change and lower driving voltage. Two-dimensional liquid-crystal director and finite-difference time-domain optical simulations are used to select liquid crystal material parameters and optimize the dimension of the microcavity structured material.