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Ultra-Low Viscosity Liquid Crystal Materials, Haiwei Chen, Minggang Hu, Fenglin Peng, Jian Li, Zhongwei An, Shin-Tson Wu
Ultra-Low Viscosity Liquid Crystal Materials, Haiwei Chen, Minggang Hu, Fenglin Peng, Jian Li, Zhongwei An, Shin-Tson Wu
Faculty Bibliography 2010s
We report five ultra-low viscosity nematic liquid crystal mixtures with birefringence around 0.1, dielectric anisotropy in the range of 3 to 6, and clearing temperature about 80 degrees C. A big advantage of these low viscosity mixtures is low activation energy, which significantly suppresses the rising rate of viscosity at low temperatures. Using our mixture M3 as an example, the response time of a 3-mu m cell at -20 degrees C is only 30 ms. Widespread application of these materials for display devices demanding a fast response time, especially at low temperatures, is foreseeable.
Fast-Response Liquid Crystals For High Image Quality Wearable Displays, Zhenyue Luo, Fenglin Peng, Haiwei Chen, Minggang Hu, Jian Li, Zhongwei An, Shin-Tson Wu
Fast-Response Liquid Crystals For High Image Quality Wearable Displays, Zhenyue Luo, Fenglin Peng, Haiwei Chen, Minggang Hu, Jian Li, Zhongwei An, Shin-Tson Wu
Faculty Bibliography 2010s
We demonstrate two ultra-low viscosity liquid crystal mixtures to enable field-sequential-color wearable displays for low temperature operation, while keeping a wide color gamut. Our mixtures offer similar to 4X faster response time than a commercial material at 20 degrees C and similar to 8X faster at -20 degrees C. Other major attractive features include: (1) submillisecond response time at room temperature and vivid color even at -20 degrees C without a heating device, (2) high brightness and excellent ambient contrast ratio, and (3) suppressed color breakup with 360Hz frame rate.
Fast-Response Infrared Phase Modulator Based On Polymer Network Liquid Crystal, Fenglin Peng, Haiwei Chen, Suvagata Tripathi, Robert J. Twieg, Shin-Tson Wu
Fast-Response Infrared Phase Modulator Based On Polymer Network Liquid Crystal, Fenglin Peng, Haiwei Chen, Suvagata Tripathi, Robert J. Twieg, Shin-Tson Wu
Faculty Bibliography 2010s
We report a high birefringence terphenyl liquid crystal mixture, designated as M3, for infrared phase modulation with special emphasis on mid-wave infrared (MWIR). In addition to high birefringence, M3 exhibits excellent UV stability, modest dielectric anisotropy, and a very broad nematic range. The high birefringence enables a thin cell gap to be used for achieving a 2 pi phase change while maintaining a high transmittance (T > 98%) in the MWIR region. To achieve fast response time, we employed a polymer network liquid crystal using M3 with 2 pi phase change at lambda= 4 mu m and 3.6-ms response time. This …
High Performance Liquid Crystal Displays With A Low Dielectric Constant Material, Haiwei Chen, Fenglin Peng, Zhenyue Luo, Daming Xu, Shin-Tson Wu, Ming-Chun Li, Seok-Lyul Lee, Weng-Ching Tsai
High Performance Liquid Crystal Displays With A Low Dielectric Constant Material, Haiwei Chen, Fenglin Peng, Zhenyue Luo, Daming Xu, Shin-Tson Wu, Ming-Chun Li, Seok-Lyul Lee, Weng-Ching Tsai
Faculty Bibliography 2010s
We report high performance liquid crystal displays (LCDs), including fringe field switching (p-FFS) and in-plane switching (p-IPS), with a small average dielectric constant (epsilon) but positive dielectric anisotropy material. Our low e based p-FFS and p-IPS LCDs offer several attractive properties, such as high transmittance, low operation voltage, fast response time (even at -20 degrees C), which is particularly desirable for outdoor applications of mobile or wearable display devices, and suppressed flexoelectric effect. Combining these advantages with the inherent outstanding features, such as wide viewing angle, no grayscale inversion, negligible color shift, and pressure resistance, the low e LC based …
Cr:Znse Laser Incorporating Anti-Reflection Microstructures Exhibiting Low-Loss, Damage-Resistant Lasing At Near Quantum Limit Efficiency, Sean Mcdaniel, Douglas Hobbs, Bruce Macleod, Ernest Sabatino, Patrick Berry, Kenneth Schepler, William Mitchell, Gary Cook
Cr:Znse Laser Incorporating Anti-Reflection Microstructures Exhibiting Low-Loss, Damage-Resistant Lasing At Near Quantum Limit Efficiency, Sean Mcdaniel, Douglas Hobbs, Bruce Macleod, Ernest Sabatino, Patrick Berry, Kenneth Schepler, William Mitchell, Gary Cook
Faculty Bibliography 2010s
We report demonstration of efficient continuous-wave lasing from chromium-doped zinc selenide using anti-reflection microstructures (ARMs) in place of thin-film AR coatings or Brewster angle cavity geometries. ARM textures are more resistant to laser-induced damage than coatings, exhibit low-loss, wide angular acceptance, broad wavelength effectiveness, and are not susceptible to water absorption. Slope-efficiencies of 68% were achieved, which compares favorably to the thin-film control samples at 58% for the same cavity. ARMs hold promise for near-term power scaling and wavelength agility of transition-metal-ion doped II-VI lasers.
Multimaterial Disc-To-Fiber Approach To Efficiently Produce Robust Infrared Fibers, Guangming Tao, Soroush Shabahang, Shixun Dai, Ayman F. Abouraddy
Multimaterial Disc-To-Fiber Approach To Efficiently Produce Robust Infrared Fibers, Guangming Tao, Soroush Shabahang, Shixun Dai, Ayman F. Abouraddy
Faculty Bibliography 2010s
A critical challenge in the fabrication of chalcogenide-glass infrared optical fibers is the need for first producing large volumes of high-purity glass-a formidable task, particularly in the case of multicomponent glasses. We describe here a procedure based on multimaterial coextrusion of a hybrid glass-polymer preform from which extended lengths of robust infrared fibers are readily drawn. Only similar to 2 g of glass is required to produce 46 m of step-index fiber with core diameters in the range 10-18 mu m. This process enables rapid prototyping of a variety of glasses for applications in the delivery of quantum cascade laser …
Photosensitivity And Thermal Stability Of Uv-Induced Fiber Bragg Gratings In Phosphate Glass Fibers, Lingyun Xiong, Peter Hofmann, Axel Schülzgen, N. Peyghambarian, Jacques Albert
Photosensitivity And Thermal Stability Of Uv-Induced Fiber Bragg Gratings In Phosphate Glass Fibers, Lingyun Xiong, Peter Hofmann, Axel Schülzgen, N. Peyghambarian, Jacques Albert
Faculty Bibliography 2010s
The photosensitivity of highly Er/Yb doped and undoped phosphate glass fibers is characterized under irradiation with intense pulsed 193 nm light from an ArF excimer laser through a phase mask. The ultraviolet photosensitivity of the active fibers is shown to be roughly half that of the passive fibers. We also demonstrate that the strong growth of the fiber Bragg grating reflectivity observed upon heating at temperatures between 100 - 250 degrees C is directly related to the UV irradiation time, but not to the size of the index modulation of the seed grating or even to the fiber type (Er/Yb …
Dual-Arm Z-Scan Technique To Extract Dilute Solute Nonlinearities From Solution Measurements, Manual R. Ferdinandus, Matthew Reichert, Trenton R. Ensley, Honghua Hu, Dmitry A. Fishman, Scott Webster, David J. Hagan, Eric W. Van Stryland
Dual-Arm Z-Scan Technique To Extract Dilute Solute Nonlinearities From Solution Measurements, Manual R. Ferdinandus, Matthew Reichert, Trenton R. Ensley, Honghua Hu, Dmitry A. Fishman, Scott Webster, David J. Hagan, Eric W. Van Stryland
Faculty Bibliography 2010s
We present a technique in which small solute nonlinearities may be extracted from large solvent signals by performing simultaneous Z-scans on two samples (solvent and solution). By using a dual-arm Z-scan apparatus with identical arms, fitting error in determining the solute nonlinearity is reduced because the irradiance fluctuations are correlated for both the solvent and solution measurements. To verify the sensitivity of this technique, the dispersion of nonlinear refraction of a squaraine molecule is measured. Utilizing this technique allows for the effects of the solvent n(2) to be effectively eliminated, thus overcoming a longstanding problem in nonlinear optical characterization of …
Feature Issue Introduction: Mid-Ir Photonic Materials, Juejun Hu, Jerry Meyer, Kathleen Richardson, Lawrence Shah
Feature Issue Introduction: Mid-Ir Photonic Materials, Juejun Hu, Jerry Meyer, Kathleen Richardson, Lawrence Shah
Faculty Bibliography 2010s
The mid-infrared (mid-IR, 2.5 to 10 mu m wavelengths) is a strategically important spectral band for an array of applications such as thermal imaging, chem/bio sensing, spectroscopy, infrared countermeasures, and free space communications. Mid-IR photonics have emerged as an active area of investigation in recent years, largely spurred by the rapid progress of cascade laser sources, uncooled detectors, and specialty mid-IR optical fibers. The 26 papers of this feature issue focus on the leading enabling material technologies for mid-IR photonics, and encompass recent advances in both active (lasers and detectors) and passive (fibers and waveguides) components. Linear and nonlinear photon-matter …
Si-Cmos Compatible Materials And Devices For Mid-Ir Microphotonics, Pao Tai Lin, Vivek Singh, Jianfei Weng, Hongtao Lin, Juejun Hu, Kathleen Richardson, J. David Musgraves, Igor Luzinov, Joel Hensley, Lionel C. Kimberling, Anu Agarwal
Si-Cmos Compatible Materials And Devices For Mid-Ir Microphotonics, Pao Tai Lin, Vivek Singh, Jianfei Weng, Hongtao Lin, Juejun Hu, Kathleen Richardson, J. David Musgraves, Igor Luzinov, Joel Hensley, Lionel C. Kimberling, Anu Agarwal
Faculty Bibliography 2010s
CMOS compatible mid-Infrared (mid-IR) microphotonics including (1) broadband SOUP (Silicon on Oxide Undercladding Pedestal) waveguides; and (2) mid-IR transparent chalcogenide glass (ChGs) waveguides monolithically integrated with a PbTe thin film photodetector; are demonstrated. Using a pedestal undercladding geometry we obtain an optical loss for our Si waveguide which is 10 dB/cm lower compared to other waveguides using planar SiO2 cladding at lambda = 5 mu m, and a fundamental mode is seen over a broad mid-IR spectral range. To realize a fully integrated mid-IR on-chip system, in parallel, we develop PbTe thin film detectors that can be deposited on various …
Modeling Of The Induced Refractive Index Kinetics In Photo-Thermo-Refractive Glass, Julien Lumeau, Leonid B. Glebov
Modeling Of The Induced Refractive Index Kinetics In Photo-Thermo-Refractive Glass, Julien Lumeau, Leonid B. Glebov
Faculty Bibliography 2010s
Photo-thermo-refractive (PTR) glass is a photosensitive multi-component silicate glass that exhibits refractive index change after successive UV-exposure and thermal treatment. The refractive index change was demonstrated to be associated with the precipitation of NaF nano-crystals in the glass matrix. This paper presents a systematic study of the dependence of the refractive index change on dosage of UV-exposure and thermal treatment duration and temperature in already UV-exposed and nucleated samples. It is shown using Avrami plots that the refractive index change in PTR glass is determined by a diffusion-controlled growth of particles from pre-existing nuclei while all coefficients have exponential dependence …
Incorporation Of Luminescent Cdse/Zns Core-Shell Quantum Dots And Pbs Quantum Dots Into Solution-Derived Chalcogenide Glass Films, Spencer Novak, Luca Scarpantonio, Jacklyn Novak, Marta Dai Pré, Alessandro Martucci, Jonathan D. Musgraves, Nathan D. Mcclenaghan, Kathleen Richardson
Incorporation Of Luminescent Cdse/Zns Core-Shell Quantum Dots And Pbs Quantum Dots Into Solution-Derived Chalcogenide Glass Films, Spencer Novak, Luca Scarpantonio, Jacklyn Novak, Marta Dai Pré, Alessandro Martucci, Jonathan D. Musgraves, Nathan D. Mcclenaghan, Kathleen Richardson
Faculty Bibliography 2010s
CdSe/ZnS core-shell quantum dots (CSQDs) and PbS quantum dots (QDs) were synthesized using a colloidal method and incorporated into Ge23Sb7S70 glass films via a solution-derived approach to film formation. Photoluminescence (PL) from the QDs inside the glass matrix was observed in the visible (CdSe/ZnS) and near-IR (PbS) regions. Properties of the QDs were found to be environment dependent, with the amine solvent partially quenching the luminescence. The PL lifetime of the CdSe/ZnS CSQDs and PbS QDs in the glass film was decreased to varying degrees from that of the QDs in pure chloroform. Monitoring the steady-state PL intensity and luminescence …
Feature Issue Introduction: Optical Ceramics, Jas Sanghera, Takunori Taira, Romain Gaume
Feature Issue Introduction: Optical Ceramics, Jas Sanghera, Takunori Taira, Romain Gaume
Faculty Bibliography 2010s
This feature offers 11 papers in the field of optical ceramics, and encompasses advances in optics, materials science, condensed matter, as well as physics and chemistry relevant to the development of new optical materials. Topics covered include material technologies in the field of polycrystalline ceramics, single crystals, and glass ceramics in the form of bulk and microstructured materials along with methods to fabricate the materials and a description of their optical properties pertinent for many applications.
Thermal Poling Behavior And Shg Stability In Arsenic-Germanium Sulfide Glasses, William T. Shoulders, Jacklyn Novak, Marc Dussauze, J. David Musgraves, Kathleen Richardson
Thermal Poling Behavior And Shg Stability In Arsenic-Germanium Sulfide Glasses, William T. Shoulders, Jacklyn Novak, Marc Dussauze, J. David Musgraves, Kathleen Richardson
Faculty Bibliography 2010s
Second-order optical properties of thermally poled arsenic-germanium sulfide glasses have been investigated. Parallel studies of glass structure changes upon poling and/or visible cw-laser irradiation and complete SHG quantitative analysis have been performed. Key parameters and poling mechanisms influencing largely SHG stability and efficiency have been pointed out.
Feature Issue Introduction: Specialty Optical Fibers, J. Ballato, A. F. Abouraddy
Feature Issue Introduction: Specialty Optical Fibers, J. Ballato, A. F. Abouraddy
Faculty Bibliography 2010s
"For groundbreaking achievements concerning the transmission of light in fibers for optical communication." With this citation, the Nobel Committee bestowed the 2009 Nobel Prize in Physics to Dr. Charles Kao and validated the global importance of optical fibers. That said, technological demands march on and the applications in which optical fibers are employed continue to expand. Further, both existing and emerging applications are requiring greater performance and functionality, beyond those associated with telecommunications, from the enabling optical fibers; and so it is timely to offer this special issue that compiles recent advances in specialty optical fibers.
Polymer-Stabilized Blue Phase Liquid Crystal With A Negative Kerr Constant, Yan Li, Yuan Chen, Jin Yan, Yifan Liu, Jianpeng Cui, Qionghua Wang, Shin-Tson Wu
Polymer-Stabilized Blue Phase Liquid Crystal With A Negative Kerr Constant, Yan Li, Yuan Chen, Jin Yan, Yifan Liu, Jianpeng Cui, Qionghua Wang, Shin-Tson Wu
Faculty Bibliography 2010s
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 (similar to 1%) hysteresis and fast response time (similar to 1ms) at the room temperature, although its Kerr …
Spectral Engineering Of Optical Fiber Preforms Through Active Nanoparticle Doping, T. Lindstrom, E. Garber, D. Edmonson, T. Hawkins, Y. Chen, G. Turri, M. Bass, J. Ballato
Spectral Engineering Of Optical Fiber Preforms Through Active Nanoparticle Doping, T. Lindstrom, E. Garber, D. Edmonson, T. Hawkins, Y. Chen, G. Turri, M. Bass, J. Ballato
Faculty Bibliography 2010s
Europium doped alkaline earth fluoride [Eu:AEF(2) (AE = Ca, Sr, Ba)] nanoparticles were synthesized and systematically incorporated into the core of modified chemical vapor deposition (MCVD)-derived silica-based preforms by solution doping. The resulting preforms were examined to determine the impact of the nanoparticles chemistry on the spectroscopic behavior of the glass. The dominant existence of Eu3+ was demonstrated in all preforms, which is in contrast to conventional solution doped preforms employing dissolved europium salts where Eu2+ is primarily observed. Raman spectroscopy and fluorescence lifetime measurements indicated that the nanoparticles composition is effective in controlling, at a local chemical and structural …
Femtosecond Laser Induced Photochemistry In Materials Tailored With Photosensitive Agents Invited, Arnaud Royon, Yannick Petit, Gautier Papon, Martin Richardson, Lionel Canioni
Femtosecond Laser Induced Photochemistry In Materials Tailored With Photosensitive Agents Invited, Arnaud Royon, Yannick Petit, Gautier Papon, Martin Richardson, Lionel Canioni
Faculty Bibliography 2010s
This article deals with the recent advances in photochemistry in optical materials induced by femtosecond laser pulses. The field of investigation of this paper is limited to bulk solid isotropic transparent materials (glasses and polymers), specifically tailored with photoactive agents. The formation mechanisms of laser-induced color centers, nanoclusters, nanoparticles and nanocrystallites are reviewed and argued, in particular the influence of the temperature during or after the laser irradiation. The relation between the photo-induced structures and the optical property modifications are discussed, as well as some applications.
Broadband Circularly-Polarized Infrared Emission From Multilayer Metamaterials, Samuel L. Wadsworth, Paul G. Clem, Eric D. Branson, Glenn D. Boreman
Broadband Circularly-Polarized Infrared Emission From Multilayer Metamaterials, Samuel L. Wadsworth, Paul G. Clem, Eric D. Branson, Glenn D. Boreman
Faculty Bibliography 2010s
Development of a 2D metamaterial that preferentially emits broadband circularly-polarized (CP) infrared radiation is hindered by the fact that orthogonal electric-field components are uncorrelated at the surface of the thermal emitter, a consequence of the fluctuation-dissipation theorem. We achieve broadband CP thermal emission by fabricating a meanderline quarter-wave retarder on a transparent thermal-isolation layer. Behind this isolation layer, in thermal contact with the emitter, is a wire-grid polarizer. Along with an unavoidable linear polarized radiation characteristic from the meanderline, we measured a degree of circular polarization (DOCP) of 28%, averaged over the 8- to 12 mu m band.
Polymer-Stabilized Blue Phase Liquid Crystals: A Tutorial Invited, Jin Yan, Shin-Tson Wu
Polymer-Stabilized Blue Phase Liquid Crystals: A Tutorial Invited, Jin Yan, Shin-Tson Wu
Faculty Bibliography 2010s
Blue phase liquid crystals exhibit several attractive features, such as self-assembled three-dimensional cubic structures, optically-isotropic in the voltage-off state, no need for alignment layers, and submillisecond response time. This tutorial gives step-by-step introduction on basic blue-phase materials and properties, monomers and polymerization processes, and key device performance criteria for display and photonics applications.
Focus Issue Introduction: Liquid Crystal Materials For Photonic Applications, Wei Lee, Shin-Tson Wu
Focus Issue Introduction: Liquid Crystal Materials For Photonic Applications, Wei Lee, Shin-Tson Wu
Faculty Bibliography 2010s
This special issue, "Liquid Crystal Materials for Photonic Applications," within the December 2011 publication of Optical Materials Express, highlights recent advances in liquid crystal material research. It features a collection of articles on materials and device properties of blue-phase liquid crystals, dye-doped cholesteric liquid crystals, dispersions in nematic and chiral nematic liquid crystals, and of mesophase-polymer composites.
Characterization Study Of Bonded And Unbonded Polydimethylsiloxane Aimed For Bio-Micro-Electromechanical Systems-Related Applications, Miao Liu, Quanfang Chen
Characterization Study Of Bonded And Unbonded Polydimethylsiloxane Aimed For Bio-Micro-Electromechanical Systems-Related Applications, Miao Liu, Quanfang Chen
Faculty Bibliography 2000s
Authors have demonstrated that by controlling the mixing ratio of polydimethylsiloxane's (PDMS's) two components-base polymer (part A) and a curing agent (part B)-different mechanical properties of PDMS can be achieved. Test results show that the Young's modulus decreases as the increasing of mixing ratios (A: B). However, there is a transitional mixing ratio (part A:part B=10) after which the Young's modulus is almost independent of the mixing ratio. The PDMS's thickness plays an important role in determining the mechanical properties. The results show that the thinner the PDMS, the stiffer it behaves. The bonding strength between two cured PDMS parts …