bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear Optics
Authors: Flytzanis Christos 
Published: August 2007

AbstractWe present an unified overview and classification of the main nonlinear optical effects and the underlying nonlinear optical interactions. The physical origin of these effects is analyzed and related to material features and their behavior, their characteristics and efficiency are discussed in terms of the nonlinear propagation equations. Some aspects related to nonlinear optical materials and devices are presented and connections with quantum optics, nonlinear spectroscopy and optoelectronics are stressed.
Optical Coatings
Authors: Macleod Angus 
Published: August 2007

Abstract
Optical coatings consist of thin uniform layers of material over a surface. Interference effects combine with the intrinsic properties of the materials to modify the specular properties of the surface without altering its power. Antireflection coatings reduce reflection losses, high‐reflectance coatings increase the reflectance, others divide or combine light beams perhaps according to their wavelength or direction, some are purely decorative, and there are many others of different types.
Optical Components and Systems
Authors: Litfin Gerd , Schuhmann Rainer 
Published: August 2007

Abstract
This article gives an overview of geometrical optics and includes the most important formulas as well as a few optical systems of general interest.
It describes the main optical components such as lenses, mirrors, plane plates, prisms, fibers, and thin films and their influence on light beams as light propagation and polarization. The principles of reflection and refraction are discussed as well as the optical imaging based on first‐order optics. The basic formulas are given.
The discussion on plano‐optics considers the spectral properties of filters and prisms, the change of image orientation by a single prism and prism systems, beam splitting, and polarization effects due to birefringence of crystal components. Total internal reflection can guide light in optical fibers. Different fiber types are described.
Besides single components as best‐form lenses and doublets, only multielement optical systems can meet the requirements of different imaging applications. Therefore, a selection of well‐known optical systems considering their main properties is described. This includes camera lenses, microscopes, and more sophisticated optical systems as well as a short side‐glance on the requirements of interferometers that cannot be described by the geometrical optics approach.
Furthermore, a section on optical bench systems summarizes the necessary support of optics by mechanical components. This includes bench profiles and structural systems using the micro bench.
Optical Instrumentation
Authors: Hoeschen Dietmar , Mirandé Werner 
Published: August 2007

AbstractOptical instrumentation is based on phenomena caused by optical radiation. In this article, optical radiation is limited to a wavelength range between 200 nm and 50 µm. After a short survey about the historical development of optical instrumentation, phenomena resulting from the various characteristics of optical radiation, as for instance, a wave or a particle, are considered. Based on the wavelength character, optical instrumentation used for interferometry, colorimetry, spectroscopy, diffraction, imaging, and optical frequency standards is treated. The interaction of optical radiation with matter is used in refractometry, in polarimetry, for studying matter with ultrashort pulses of radiation, and for processing matter with radiation of high‐energy density. Finally, the particle character is considered to be used for fields such as radiometry and energy conversion.
Optical Radiation Sources and Standards
Authors: Diedrich Jonathan , Dodds John 
Published: August 2007

AbstractArtificial visible and near‐visible electromagnetic radiation is produced and characterized in several different ways. From incandescent light bulbs and gas‐discharge lamps to LEDs and lasers, light sources have been evolving for years. This chapter describes the various ways that light is produced as well as standardized. The first section discusses some of the different types of sources of radiation. Illustrated along with the different sources are examples of their uses. With all these sources, standardization and calibration are very important. The second section will discuss how, along with improved technology, the methods and procedures used to realize standards have evolved. Discussed is the evolution of radiation standards leading to the current method of realizing them. In addition, we discuss the methods used to calibrate optical devices using these standards.
Photochemistry
Authors: Stevenson Kenneth L. , Horváth Ottó 
Published: August 2007

AbstractThis article presents a systematic introduction to theoretical and experimental aspects of photochemistry, along with typical examples and applications. It gives a survey of photochemical laws and fundamental principles of photophysics and photochemistry, including multiphoton processes that occur at high light intensity laser irradiation. Descriptions of experimental techniques are given for both continuous irradiation and flash photolysis, including laser spectroscopy and femtochemistry. Detailed discussions of the important theories and representative reactions in the photochemistry of organic, inorganic, and coordination compounds are also presented. Finally, some of the more significant roles photochemistry plays in nature and in modern life, such as photosynthesis, information storage, and phototherapy, are briefly introduced.
Photography, Digital
Authors: Kriss Michael A. 
Published: August 2007

AbstractDigital photography, with the advent of reasonably priced mega‐pixel digital cameras and high quality inkjet printers, is starting to challenge conventional, silver halide based imaging systems in the profitable consumer markets. This article is designed to provide a systematic review of all the technologies required to support digital photography. The digital imaging chain provides the flow and structure for reviewing the important imaging technologies including camera optics, imaging sensors and architectures, sensor speed, color reproduction, compression, image processing and digital hardcopy. In addition to the evaluation of individual imaging technologies, a systematic, system‐wide image quality assessment is provided that takes into account image quality (sharpness) and the most common image artifacts associated with digital photography.
Photonics
Authors: King Terence A. 
Published: August 2007

AbstractPhotonics concerns the generation, transmission, manipulation, and interactions of light and its applications in many varied areas in research, industry, and everyday life. This general overview of photonics draws special attention to the development of laser sources, semiconductor optics, fiber optics, and photonic techniques such as ultrafast pulse generation. The wide range of applications is reviewed with particular attention to information technology and optical communications, optical information storage, displays, sensors, and industrial applications. The rapidly growing field of applications in biophotonics and biomedical optics is also emphasized with new techniques of optical coherence tomography (OCT) and optical trapping.
Sensors, Optical
Authors: Haus Jörg , Schaefer Roland 
Published: August 2007

Abstract
In terms of dynamic range and noise, optical sensors have great advantages over their electronic or mechanical counterparts. In addition, the noncontact nature of all optical measurements avoids influences of the sensor on the measured value and, thus, measurement‐introduced systematic errors. This article gives an introduction to the components found in all kinds of optical sensors: light sources, detectors, and optical elements. On the basis of this optoelectronic toolbox, sensors for the measurement of various physical and chemical quantities are described.
Spectroscopy, Laser
Authors: Inguscio Massimo , Sasso Antonio 
Published: August 2007

Abstract
The high intensity, high spectral purity, and short‐pulse duration of laser sources have opened a new era in laser spectroscopy. Many sophisticated spectroscopic techniques have been developed during the last decades. They have allowed the investigation of the structure of atoms and molecules with great detail, making it possible to test fundamental quantum mechanics theories. Moreover, laser spectroscopy represents a very diffused tool in many other fields. A wide range of applications concern not only free atoms and molecules but also plasma physics and solid‐state physics and many other interdisciplinary fields such as chemistry, biology, and medicine. Laser spectroscopy is till now a very fascinating field of research continuously in evolution: the new techniques of laser cooling have allowed the production of condensates of atoms that represent a new state of the matter only recently explored.
Spectroscopy, Photoacoustic
Authors: Harren Frans J. M. , Laarhoven Lucas J. J. 
Published: August 2007

Abstract
After a short introduction and description of particular features of the equipment used, attention is centered on applications. Solids, surfaces, and solutions have been studied by photoacoustic spectroscopy; recent work is quoted. Gas‐phase investigations are discussed with emphasis on trace gas detection. Especially, applications in plant physiology and microbiology are considered.
Spectroscopy,Raman
Authors: Edwards Howell G. M. 
Published: August 2007

AbstractThis article describes the origins of Raman scattering and the important parameters upon which its application depends, in particular, its dependence upon molecular species concentration, molecular and crystal orientation, polarizability changes, and the wavelength and power densities of the laser excitation. The instrumentation used to record Raman spectra from the ultraviolet to the near‐infrared regions of the electromagnetic spectrum and the minimization of sample fluorescence is reviewed. Finally, some current applications of Raman spectroscopy to the characterization of materials are highlighted in the fields of biomedical diagnostics, archaeological science, art history, industrial process control, environmental science, and astrobiology. The interdisciplinarity of modern Raman‐spectroscopic technique applications is illustrated by the efforts now being made in the miniaturization of Raman spectrometers for planetary exploration as part of instrumentation suites on robotic landers—projects that bring together teams of chemists, applied spectroscopists, biologists, physicists, astronomers, space scientists, and astrobiologists.
Stereoscopy
Authors: Claus Michael , Knupfer Klaus 
Published: August 2007

Abstract
This article covers the principles of stereoscopic imaging and measurements. It explains stereoscopic image‐generation techniques and the available methods of stereoimage display. 3D measurements in stereoimages and the related mathematics are explained, together with required hardware equipment and software. The generation of products such as digital elevation models, orthophotos and semiautomatic produced maps, resulting from the 3D measurements, is explained.
Nanoparticle Coating for Advanced Optical, Mechanical and Rheological Properties
Authors: Hakim L. F. , King D. M. , Zhou Y. , Gump C. J. , George S. M. , Weimer A. W. 
Published: August 2007

AbstractPrimary titania nanoparticles were coated with ultrathin alumina films using Atomic Layer Deposition (ALD). The deposited films were highly uniform and conformal with an average growth rate of 0.2 nm per coating cycle. The alumina films eliminated the surface photocatalytic activity of titania nanoparticles, while maintained their original extinction efficiency of ultraviolet light. Deposited films provided a physical barrier that effectively prevented the titania surface from oxidizing organic material whereas conserving its bulk optical properties. Parts fabricated from coated powders by pressureless sintering had a 13 % increase in surface hardness over parts similarly fabricated from uncoated particles. Owing to its homogeneous distribution, the secondary alumina phase suppressed excessive grain growth. Alumina films completely reacted during sintering to form aluminum titanate composites, as verified by XRD. Coated particles showed a pseudoplastic behavior at low shear rates due to modified colloidal forces. This behavior became similar to the Newtonian flow of uncoated nanoparticle slurries as the shear rate increased. Suspensions of coated particles also showed a decreased viscosity relative to the viscosity of uncoated particle suspensions.
Organic Thin‐Film Photovoltaic Cells Based on Oligothiophenes with Reduced Bandgap
Authors: Uhrich C. , Schueppel R. , Petrich A. , Pfeiffer M. , Leo K. , Brier E. , Kilickiran P. , Baeuerle P. 
Published: August 2007

AbstractThe best polymeric solar cells reported so far are based on a so‐called bulk heterojunction of a polythiophene as donor and a soluble fullerene derivative as acceptor. However, these cells still suffer from an unsatisfying photovoltage, typically below 0.7 V. Here, we show that we can achieve higher photovoltages using a new terthiophene end‐capped with electron withdrawing dicyanovinyl groups (DCV3T) that increase both the ionization energy and even more strongly the electron affinity of the compound. The new material is tested in cells using a photoactive heterojunction to separate the excitons generated in the oligomer and a p‐doped wide‐gap transport layer. The solar cells show an open circuit voltage of up to 1.04 V and a broad spectral sensitivity band ranging from 420 nm to 650 nm. Solar cells based on such oligothiophenes are promising candidates for stacked organic solar cells tailored to the sun‐spectrum. Moreover, we present first examples of a new concept for organic solar cells: By blending DCV3T with fullerene C60, an enhanced generation of triplet excitons on the oligomer can be achieved via a back and forth transfer of excitons (ping‐pong‐effect).
Facile Synthesis of Nanostructured Carbon through Self‐Assembly between Block Copolymers and Carbohydrates
Authors: Rodriguez A. T. , Li X. , Wang J. , Steen W. A. , Fan H. 
Published: August 2007

AbstractA simple and direct wet chemistry method is reported to simultaneously synthesize nanostructured carbon films and particles through self‐assembly of poly(styrene)‐poly(4‐vinylpyridine) (PS‐P4VP) and carbohydrate precursors (turanose, raffinose, glucose, etc.) in two fabrication processes—spin‐coating and aerosol processing. Starting with a homogeneous solution containing PS‐P4VP and carbohydrates, evaporation of solvent during either spin‐coating or an aerosol process leads to the formation of ordered mesostructured films and particles. High temperature treatment in argon atmosphere removes PS fragments, carbonizes carbohydrates and partial PVP fragments, and results in ordered nanoporous carbon films and particles. SEM, TEM, and GISAXS characterization indicates that these nanostructured carbon materials exhibit large nanopores (> 20 nm), controlled 1–3 dimensional structures, and controlled surface chemistry. Nitrogen sorption isotherms and electrochemistry characterization indicates the accessibility of the carbon nanopores to both gas phase and aqueous phase. Results suggest that the nanostructured carbon films and particles can be tuned through solvent annealing, precursor concentration, and choice of block copolymers used. These carbon materials present varied practical applications for sorption and separation, sensors, electrode materials, etc.
Towards an Understanding of Nanoparticle–Chiral Nematic Liquid Crystal Co‐Assembly
Authors: Payne J. C. , Thomas E. L. 
Published: August 2007

AbstractThe fabrication of a one‐dimensional photonic crystal without time‐reversal and space‐inversion symmetries was pursued. Theoretical studies predict that such a system would exhibit unusual optical properties, including indirect photonic bandgaps and backward wave propagating eigenmodes. Such a system can be created experimentally by combing magnetooptical nanoparticles with a chiral nematic liquid crystal. The manner in which nanoparticles co‐assemble with a chiral nematic liquid crystal was investigated. It was determined that the addition of nanoparticles to a 5CB‐COC system disrupts the system's helical structure. This disruption lowers the system's phase transition temperatures and inhibits the system's ability to form reflectivity peaks.
Solvent Dependent Shape and Magnetic Properties of Doped ZnO Nanostructures
Authors: Clavel G. , Willinger M.‐G. , Zitoun D. , Pinna N. 
Published: August 2007

AbstractThis study reports on a new solution phase synthesis leading to cobalt and manganese doped ZnO which have been theoretically predicted ferromagnetic at room temperature. The solvothermal synthesis involving the reaction of zinc and cobalt acetate or manganese oleate with benzyl alcohol leads to pure inorganic nanoparticles that are diluted magnetic semiconductors. The addition of an inert solvent, that is used in order to control the amount of benzyl alcohol, drastically influences the particles morphology and strongly affects the magnetic behaviors. Cobalt doped particles are paramagnetic or ferromagnetic depending on the synthesis conditions. In order to exclude the formation of secondary phases and/or metal clusters and to understand the role of the solvent on the magnetic properties, the local structure of Co2+ and Mn2+ in the wurtzite ZnO matrix were characterized by XRD, UV‐visible diffuse reflectance and electron paramagnetic resonance.
Printable All‐Organic Electrochromic Active‐Matrix Displays
Authors: Andersson P. , Forchheimer R. , Tehrani P. , Berggren M. 
Published: August 2007

AbstractAll‐organic active matrix addressed displays based on electrochemical smart pixels made on flexible substrates are reported. Each individual smart pixel device combines an electrochemical transistor with an electrochromic display cell, thus resulting in a low‐voltage operating and robust display technology. Poly(3,4‐ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) served as the active material in the electrochemical smart pixels, as well as the conducting lines, of the monolithically integrated active‐matrix display. Different active‐matrix display addressing schemes have been investigated and a matrix display fill factor of 65 % was reached. This is achieved by combining a three‐terminal electrochemical transistor with an electrochromic display cell architecture, in which an additional layer of PEDOT:PSS was placed on top of the display cell counter electrode. In addition, we have evaluated different kinds of electrochromic polymer materials aiming at reaching a high color switch contrast. This work has been carried out in the light of achieving a robust display technology that is easily manufactured using a standard label printing press, which forced us to use the fewest different materials as well as avoiding exotic and complex device architectures. Together, this yields a manufacturing process of only five discrete patterning steps, which in turn promise for that the active matrix addressed displays can be manufactured on paper or plastic substrates in a roll‐to‐roll production procedure.
Efficient Deep‐Blue Organic Light‐Emitting Diodes: Arylamine‐Substituted Oligofluorenes
Authors: Gao Z. Q. , Li Z. H. , Xia P. F. , Wong M. S. , Cheah K. W. , Chen C. H. 
Published: August 2007

AbstractNovel deep‐blue‐light‐emitting diphenylamino and triphenylamino end‐capped oligofluorenes were synthesized by double palladium‐catalyzed Suzuki cross‐coupling of dibromo‐oligofluorene with the corresponding boronic acid as a key step. These oligofluorenes exhibit deep‐blue emission (λemmax = 429–432 nm), low and reversible electrochemical oxidation (highest occupied molecular orbital = 5.15–5.20 eV), high fluorescence quantum yield (ΦFL = 0.61–0.93), and good thermal properties (glass‐transition temperature, Tg = 99–195 °C and decomposition temperature, Tdec > 450 °C). Remarkably, saturated deep‐blue organic light‐emitting diodes, made from these oligofluorenes as dopant emitters, have been achieved with excellent performance and maximum efficiencies up to 2.9 cd A–1 at 2 mA cm–2 (external quantum efficiency of 4.1 %) and with Commission Internationale de l'Éclairage (x,y) coordinates of (0.152,0.08), which is very close to the National Television System Committee standard blue.
A Blue‐Light‐Emitting Polymer with a Rigid Backbone for Enhanced Color Stability
Authors: Park S. H. , Jin Y. , Kim J. Y. , Kim S. H. , Kim J. , Suh H. , Lee K. 
Published: August 2007

AbstractDespite the promising expectations of poly(fluorene) (PF)‐type materials as efficient blue‐light‐emitting polymers, the devices based on these materials are not yet fully utilized. Under prolonged operation of the devices, the PF‐type materials undergo degradation with the appearance of a long‐range emission around 2.2–2.3 eV. As a consequence, the emissive color changes from blue to green with a decrease in the device efficiency. Here, an innovative approach that leads to a new blue‐emitting polymer with remarkable color stability is reported. By modifying the chemical structure of PF to inhibit the formation of keto defects, it is demonstrated that the devices exhibit excellent color stability. This new blue‐emitting polymer, poly(2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta‐[def]phenanthrene)) (PCPP), emits a stabilized, efficient blue electroluminescence without exhibiting any peak in the long‐wavelength region even after prolonged operation of the devices in air.
High Electroactivity of Polyaniline in Supercapacitors by Using a Hierarchically Porous Carbon Monolith as a Support
Authors: Fan L.‐Z. , Hu Y.‐S. , Maier J. , Adelhelm P. , Smarsly B. , Antonietti M. 
Published: August 2007

AbstractA high‐performance polyaniline electrode was prepared by potentiostatic deposition of aniline on a hierarchically porous carbon monolith (HPCM), which was carbonized from the mesophase pitch. A capacitance value as high as 2200 F g–1 (per weight of polyaniline) is obtained at a power density of 0.47 kW kg–1 and an energy density of 300 W h kg–1. This active material deposited on HPCM also has the advantageous of high stability. These properties can be essentially attributed to the backbone role of HPCM. The method also has the advantage of a topology that is favorable for kinetics at high power densities, thus, contributing to the increase of ionic conductivity and power density. There is also no need for a binder, which not only lowers the preparation costs but also offers advantages in terms of stability and performance.