bluuebunny/crossref_metadata_2025 huggingface dataset:
Root Surface Biomodification With EDTA for the Treatment of Gingival Recession With a Semilunar Coronally Repositioned Flap
Authors: Bittencourt Sandro , Ribeiro Érica Del Peloso , Sallum Enilson Antônio , Sallum Antônio Wilson , Nociti Francisco Humberto , Casati Márcio Zaffalon
Published: August 2007

Background: The purpose of this randomized clinical trial was to evaluate the outcome of gingival recession therapy using the semilunar coronally repositioned flap (SCRF) with or without EDTA application for root surface biomodification.

Methods: Fifteen patients with bilateral Miller Class I buccal gingival recessions (≤4.0 mm) were selected. Thirty teeth with recessions were assigned randomly to receive the semilunar coronally repositioned flap with (SCRF‐E group) or without (SCRF group) the application of an EDTA gel. Recession height (RH), recession width (RW), width (WKT) and thickness of keratinized tissue, probing depth, and clinical attachment level (CAL) were measured at baseline and 6 months post‐surgery. Patient perception of root sensitivity and postoperative pain also was evaluated.

Results: Both treatments yielded significant improvements in terms of RH and RW decrease and CAL gain compared to baseline values. For SCRF‐E and SCRF, the average root coverage was 70.2% and 90.1%, respectively (P = 0.01), and the complete root coverage was 40.0% and 66.7%, respectively. Only the SCRF group had a significant (P <0.05) increase in WKT. The SCRF group showed a greater reduction (P <0.05) in RW and RH compared to the SCRF‐E group. No patient in either group reported any pain during the postoperative course; however, 6 months later, patients in the SCRF‐E group complained more of residual or new root sensitivity compared to patients in the SCRF group.

Conclusion: The use of EDTA gel as a root surface biomodifier agent negatively affected the outcome of root coverage with the SCRF.
Implant Placement With or Without Simultaneous Tooth Extraction in Patients Taking Oral Bisphosphonates: Postoperative Healing, Early Follow‐Up, and the Incidence of Complications in Two Private Practices
Authors: Fugazzotto Paul A. , Lightfoot W. Scott , Jaffin Robert , Kumar Ashkay
Published: August 2007

Background: The development of bisphosphonate‐associated osteonecrosis in patients with a history of intravenous bisphosphonate therapy is a significant cause of concern in clinical periodontal practice. The role of oral bisphosphonates in the development of bisphosphonate‐associated osteonecrosis is less clear. This article documents the results of treatment of patients with a history of oral bisphosphonate therapy in two private periodontal practices. The study was a retrospective analysis of case records of patients treated as part of routine periodontal and implant treatment.

Methods: Patients with a history of oral bisphosphonate therapy of various durations were treated with implant placement and restoration or tooth extraction, immediate placement, and restoration. These patients were followed for 12 to 24 months after implant placement. The incidence of hard and soft tissue complications, including the development of osteonecrosis, was noted.

Results: No osteonecrosis was noted immediately postoperatively or during the follow‐up period in 61 patients. One patient demonstrated a small tissue dehiscence at the 1‐week postoperative examination following extraction of a mandibular first molar and simultaneous implant placement in the area of a prominent torus. No other postoperative complications were noted. All implants were functioning successfully by the Albrektsson criteria 12 to 24 months post‐insertion.

Conclusions: A history of oral bisphosphonate use for a mean period of 3.3 years (range, 1 to 5 years) was not found to be a contributing factor to the development of osteonecrosis following implant placement in intact ridges or tooth extraction with immediate implant placement. However, there is no doubt that larger controlled studies and retrospective reports are needed.
Hypoxia and Reoxygenation Augment Bone‐Resorbing Factor Production From Human Periodontal Ligament Cells
Authors: Motohira Hitoshi , Hayashi Joichiro , Tatsumi Junichi , Tajima Masamichi , Sakagami Hiroshi , Shin Kitetsu
Published: August 2007

Background: Oxygen deficiency caused by occlusal trauma and smoking may be associated with bone resorption in periodontitis. In the present study, the effects of hypoxia and reoxygenation on the production of bone‐resorbing factors by cultured human periodontal ligament (PDL) cells were examined.

Methods: Human PDL cells were cultured in 1% O2 (hypoxia), 20% O2 (normal oxygen tension [normoxia]), or an oxygen concentration that went from 1% to 20% (reoxygenation). The concentrations of bone‐resorbing factors, i.e., vascular endothelial growth factor (VEGF), interleukin (IL)‐6 and ‐1β, tumor necrosis factor‐alpha (TNF‐α), and prostaglandin E2 (PGE2), in the cell culture supernatants were determined by enzyme‐linked immunosorbent assay. Expression of the corresponding mRNAs was detected by reverse transcription‐polymerase chain reaction.

Results: Significantly higher extracellular concentrations of VEGF and IL‐6 were detected along with greater corresponding mRNA expression in the hypoxia group compared to the normoxia group. The protein production and mRNA expression of IL‐1β were observed only in the hypoxia group. Neither TNF‐α nor PGE2 was detectable in samples from either group, whereas cyclooxygenase‐2 mRNA was detected. However, PGE2 was detected after reoxygenation. Furthermore, VEGF and IL‐6 and ‐1β production also tended to increase in extracellular concentration and mRNA level after reoxygenation.

Conclusion: Hypoxia and reoxygenation may stimulate the PDL to produce VEGF, IL‐6 and ‐1β, and PGE2, which could result in the resorption of alveolar bone in periodontitis.
Clinical and Microbiologic Changes Associated With the Combined Use of a Powered Toothbrush and a Triclosan/Copolymer Dentifrice: A 3‐Year Prospective Study
Authors: Bogren Anna , Teles Ricardo P. , Torresyap Gay , Haffajee Anne D. , Socransky Sigmund S. , Wennström Jan L.
Published: August 2007

Background: Different means are available for self‐performed oral hygiene. The aim of this study was to evaluate the clinical and microbiologic effects of a preventive homecare program including the combined use of a powered toothbrush and a triclosan/copolymer‐containing dentifrice.

Methods: A total of 160 adult subjects without signs of destructive periodontal disease were recruited for this 3‐year randomized controlled trial. The subjects were assigned to a homecare program using an oscillating/rotating powered toothbrush and a triclosan/copolymer/fluoride‐containing dentifrice (test) or a manual toothbrush and a standard fluoride‐containing dentifrice (control). Supragingival polishing and reinforcement of homecare procedures were provided every 6 months. Plaque, bleeding on probing (BOP), and probing depth (PD) were scored at baseline and after 1, 2, and 3 years. Subgingival plaque samples were taken from the mesial aspect of each tooth at baseline and after 1, 2, and 3 years and were analyzed for their content of 40 bacterial species using checkerboard DNA‐DNA hybridization. All data analyses were based on “intention‐to‐treat” with the subject as the statistical unit.

Results: Compared to baseline, no significant changes in clinical parameters were observed during the 3 years, except for a reduction in the mean PD at the 2‐ and 3‐year follow‐up examinations (P <0.05). No significant differences were found between the two groups with regard to plaque, BOP, or PD or in the mean counts of the 40 species at any time point.

Conclusion: The study failed to prove additional benefits of the combined use of a powered toothbrush and a triclosan/copolymer‐containing dentifrice in adult subjects without signs of destructive periodontal disease.
Commentary: Two‐Piece Implants With Turned Versus Microtextured Collars
Authors: Cosyn Jan , Sabzevar Mehran Moradi , De Wilde Peter , De Rouck Tim
Published: August 2007

Implant companies have been promoting two‐piece implants with microtextured collars in the interest of hard tissue preservation and/or soft tissue integration. However, this rationale may not be justified. Based on comparative studies currently available, it is unclear whether microroughened implant necks reduce crestal bone loss. A possible effect may be overruled by the establishment of a biologic width or by other factors influencing crestal bone remodeling. In addition, the orientation and attachment of the collagen fibers in the peri‐implant mucosa are a little different because the surface roughness varies at the level of the implant neck. The clinician should be cautious when using these modified implants because the impact of microtextured collars on the initiation and progression of peri‐implant pathology is currently unknown.
Effects of EDTA Gel Preconditioning of Periodontally Affected Human Root Surfaces on Chlorhexidine Substantivity – An SEM Study
Authors: Gamal Ahmed Y. , Mailhot Jason M.
Published: August 2007

Background: Infection control is an important requirement during the early stages of periodontal healing. This study was performed to assess the preconditioning effect of EDTA gel on chlorhexidine (CHX) substantivity to periodontally involved root surfaces.

Methods: Eighty patients with severe chronic periodontitis were enrolled in this study. Following cause‐related therapy, patients were divided randomly into four groups. Each group consisted of 20 subjects with one tooth that was diagnosed as hopeless and designated for extraction. In group 1 (G1), selected periodontal pockets were filled with a placebo gel in a silica base for 2 minutes. Exposed roots in group 2 (G2) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the placebo gel. Pockets in group 3 (G3) were filled with 0.12% CHX digluconate gel in a silica base. Exposed roots in group 4 (G4) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the CHX gel. Four teeth from each group were extracted immediately and at 3, 12, 24, and 48 hours for SEM evaluation.

Results: G1 and G2 specimens showed no evidence of silica adherent to any of the examined root surfaces. At 3 hours following CHX gel application, G3 specimens showed marked reduction in CHX‐coated silica. At 24 and 48 hours following EDTA and CHX gel application, G4 specimens demonstrated adherent CHX‐coated silica particles despite the reclogging of the tubule orifices.

Conclusion: EDTA and CHX gel root conditioning is a valuable regimen that improves CHX substantivity to periodontally involved root surfaces.
Phthalic Acid and Derivatives
Authors: Lorz Peter M. , Towae Friedrich K. , Enke Walter , Jäckh Rudolf , Bhargava Naresh , Hillesheim Wolfgang
Published: August 2007

The article contains sections titled:1.Phthalic Acid2.Phthalic Anhydride2.1.Physical Properties2.2.Chemical Properties2.3.Resources and Raw Materials2.4.Production2.4.1.Gas‐Phase Oxidation2.4.1.1.Catalyst and Reaction Mechanism2.4.1.2.Apparatus and Important Process Steps in the Gas‐Phase Oxidation ofo‐Xylene2.4.2.Fluidized‐Bed Oxidation2.4.3.Liquid‐Phase Oxidation ofo‐Xylene2.5.Environmental Protection2.6.Quality Specifications and Analysis2.7.Economic Aspects2.8.Storage and Transportation2.9.Uses3.Phthalimide3.1.Properties3.2.Production3.2.1.Production from Phthalic Anhydride and Ammonia3.2.2.Production from Phthalic Anhydride and Urea3.2.3.Production fromo‐Xylene3.3.Uses4.Phthalonitrile4.1.Properties4.2.Production4.2.1.Production fromo‐Xylene4.2.2.Production from Phthalic Acid Derivatives4.3.Uses5.Phthalates5.1.Physical and Chemical Properties5.2.Raw Materials5.3.Production5.4.Environmental Protection5.5.Quality Specifications5.6.Storage and Transportation5.7.Uses5.8.Economic Aspects6.Toxicology6.1.Use of and Exposure to Phthalic Acid and Derivatives6.2.Toxicological Profiles6.2.1Phthalic Acid6.2.2Phthalic Anhydride6.2.3Phthalimide6.2.4.Phthalonitrile6.2.5.Phthalate Esters6.2.5.1.Metabolism and Toxicokinetics6.2.5.2.Acute Toxicity6.2.5.3.Irritation and Sensitizing Potential6.2.5.4.Repeated DEHP Dosing6.2.5.5.Genotoxicity and Mutagenicity6.2.5.6.Carcinogenicity6.2.5.7.Reproductive Toxicity6.2.5.8.Effects of Phthalate Esters by Groups6.3Risk Assessment6.3.1Biomonitoring and Human Exposure to Phthalate Esters6.3.2Carcinogenicity6.3.3Toxicity to Reproduction6.4Risk Management
Polystyrene and Styrene Copolymers
Authors: Maul Jürgen , Frushour Bruce G. , Kontoff Jeffrey R. , Eichenauer Herbert , Ott Karl‐Heinz , Schade Christian
Published: August 2007

The article contains sections titled:1.Polystyrene1.1.Introduction1.2.Production1.2.1.Bulk Polymerization1.2.2.Suspension Polymerization1.3.Properties1.3.1.Chemical Properties1.3.2.Physical and Processing Properties1.4.Processing and Uses1.5.Quality Specifications1.6.Storage and Transportation1.7.Recycling1.8.Environmental Aspects2.Styrene – Acrylonitrile (SAN) Copolymers2.1.Production2.2.Properties2.3.Processing2.4.Uses and Economic Aspects2.5.Blending of SAN3.Barrier Resins4.Other Copolymers4.1.α‐Methylstyrene – Acrylonitrile Copolymers4.2.Styrene – Methyl Methacrylate Copolymers4.3.Styrene – Maleic Anhydride Copolymers4.4.Styrene – Maleimide Copolymers4.5.Styrene – Acrylate Copolymers5.Acrylonitrile – Butadiene – Styrene (ABS) Polymers5.1.Definition and Structure5.1.1.Historical Aspects5.1.2.Structural Principles5.1.3.Synthesis of the Two‐Phase Structure5.1.4.Properties of the Resin Matrix5.2.Structure – Property Relationships5.3.Production of ABS Polymers5.3.1.ABS Production by Emulsion Polymerization5.3.2.Production of the Matrix Copolymer5.3.3.ABS Production by Bulk Polymerization5.3.4.Process Combinations5.3.5.Other Processes5.3.6.Additives5.4.Quality Assurance and Standardization5.5.Properties5.6.Special Product Modifications5.7.Legal Aspects5.8.Storage and Transportation5.9.Uses5.10.Economic Aspects5.11.Recycling5.12.ABS‐Analogous Systems5.12.1.ASA, AES, and ACS Polymers5.12.2.MBS and MABS Polymers5.13.ABS Blends
Optical and Laser Scanning Technology
Authors: Beiser Leo
Published: August 2007

This article consolidates optical and laser scanning technology and its utilization. The dominant scanning devices and techniques are appraised, including the polygon and holographic scanners, galvanometer and resonant scanners, fast steering mirrors, acousto‐optic and electro‐optic deflectors, and new agile beam steering methods. Also addressed are their application, classification, architecture, symmetry factors, image rotation, duty cycle, scanned resolution, optical power transfer, and cross‐scan error reduction.

Two complementary fields are presented: (Active) Laser Scanning and (Passive) Remote Sensing. While scanning devices may appear interchangeable, significant distinctions relate to the filling of their optical apertures and the use of spectrally dispersive optics. Laser scanning, having a controlled intensity distribution, projects moving illumination on very small portions of an area with functionally coherent radiation, allowing the use of diffractive optics. In contrast, remote sensing transfers spectrally broad radiation scattered from a distant object field, imaged and collected through a scanning aperture that directs the sampled radiation to a fixed detector. The scanner, intimately associated with its objective lens, is developed as oriented within a conjugate optical imaging system. Active laser radiation is thereby transferred selectively to its image. In passive sensing, ray directions are reversed, representing the conjugate transfer of radiation from remote object points back to the detector.
Optical Alignment
Authors: Ruda Mitchell C.
Published: August 2007

The philosophical approach to the alignment of optical systems is discussed. Methods of diagnosing the alignment errors through the observation of the actual image errors in the optical system are summarized. Some of the tools used in the alignment of optical systems are described. Important techniques are reviewed.
Astronomical Telescopes and Instrumentation
Authors: Fried Josef W.
Published: August 2007

Optical and mechanical designs of ground‐based astronomical telescopes for the visible region are reviewed, including special‐purpose telescopes and planned new designs for very large telescopes. The efforts to increase the angular resolution by adaptive optics are described. An overview is given of the instrumentation that is attached to telescopes to analyze and register the light collected by the telescope.
Spectroscopy, Atomic
Authors: Bonin Keith , Happer William
Published: August 2007

Atomic spectroscopy is the study of the interaction of atoms with electromagnetic radiation of various wavelengths (or frequencies). Its fundamental use has been as an aid to understanding the structure of atoms, but atomic spectroscopy has expanded to include many diverse applications such as monitoring trace impurities in steel mills and determining the elemental composition of stars.

The structure and energy levels of an atom are determined by the interactions between the positively charged nucleus and the surrounding, negatively charged electrons (and the interactions between the electrons themselves). The Coulomb potential dominates all other terms in the Hamiltonian of an atom. The spin–orbit interaction is next in importance and it can be quite large for atoms of high atomic number Z. Smaller terms in the Hamiltonian include the hyperfine interaction and the isotopic shifts due to nuclear mass differences of atoms with the same atomic number Z.

The simplest atoms (ions) are those with one electron whose energy levels and wavefunctions can be calculated analytically. The most widespread and useful model for many‐electron atoms assumes that the electrons move independently of each other in a central, self‐consistent potential, which represents the mean Coulomb energy of an electron due to the attraction of the nucleus and the repulsion of the other electrons. Residual Coulomb interactions between the electrons and other interactions neglected in the single‐particle model are accounted for with perturbation theory to provide estimates for the energy levels of the atoms. Selection rules on the allowed changes of atomic quantum numbers predict which pairs of levels can give rise to strong emission or absorption of light.

A typical spectroscopic measurement requires a light source, some optics for transporting the light, an atom source in the case of absorption spectroscopy, a spectroscopic instrument, and a detector. Some common light sources in spectroscopy are lamps, discharges, flames, lasers, and natural sources such as the sun and the stars. Atoms for absorption spectroscopy can be provided by cells, flames, furnaces, and various types of atomic beams. The most common spectroscopic instruments are prism and grating spectrometers, Fabry–Perot interferometers, and light filters. In addition to the human eye, the most widely used detectors are thermal detectors, wherein thetotal incident energyof the absorbed light causes an increase in the thermal motion of electrons in the material; and photon detectors, wherein thenumber of incident photons(and not their total energy) determines the size of the detector's response. Thermal detectors discussed here include thermocouples, bolometers, and pyroelectric detectors. Common photon detectors are photomultiplier tubes, channeltrons, photodiodes, and charge‐coupled device (CCD) arrays.
Biomedical Imaging Techniques
Authors: Hendee William R.
Published: August 2007

Biomedical images are used extensively for noninvasive exploration of the internal anatomy, physiology, and metabolism of patients suffering from virtually every disease and injury known to humankind. These images are a prototypical example of “high‐tech” medicine and are produced in many different ways, from receipt of X rays transmitted through the patient to detection of radio‐frequency signals emitted from tissues subjected to intense magnetic fields. In the past three decades, major advances in medical imaging have occurred, including X‐ray and emission‐computed tomography, real‐time, gray‐scale and Doppler ultrasound imaging, computer and digital projection radiography, and magnetic resonance imaging. Several additional imaging techniques are under exploration, including laser optical imaging, electrical impedance tomography, infrared and microwave thermography, acoustothermometry, and electrical and magnetic source imaging. Whether these or a completely new imaging technique may emerge as a significant imaging modality remains to be seen. In the meantime, additional applications of existing medical imaging methods continue to be identified, such as the use of functional magnetic resonance and emission‐computed tomography for planning and monitoring radiation treatments for cancer.
Display Technology
Authors: Theis Dietmar
Published: August 2007

Displays are the visual interface between human and electronically generated signals. Since the advent of the cathode ray tube, many other technical solutions for displays have been investigated and optimized to specific user requirements. This article attempts to structure the complexity of display categories and is focused on technology, that is, the engineering and material science aspects of electronic display devices. The fundamental technical features of cathode ray tubes (CRTs) are outlined. The larger part of the article, however, deals with flat‐panel technologies that have been developed to overcome two of the major drawbacks of CRTs, bulkiness and high weight. Flat panel displays are distinguished as either light‐generating or (external) light‐modulating devices. In the first group, the underlying basic technologies are light generation from gas discharge, cathodoluminescence, and electroluminescence. The exploitation of gas discharge for display purposes has led to the flat, direct‐view large‐area plasma displays. Cathodoluminescence—light generation through electron impact on phosphors—is used in CRT and flat‐panel devices such as vacuum fluorescence displays and field‐emission displays. Electroluminescence is the light emission caused by the action of electronic fields in solid inorganic or organic material. In the group of light‐modulating devices, the dominating technology is based on the unique optical properties of liquid crystal material. In conjunction with additional enabling thin films (e.g., orientation layers and polarizers), these devices are used in reflective, transmissive, or transflective modes. For high performance, they rely on a matrix of active switches associated with each pixel. Other technologies in the light‐modulating group make use of a variety of microparticles, which could give way to the eventual realization of electronic paper. The article ends with a short survey on projection display technologies.
Electrodynamics
Authors: Jackson J. David
Published: August 2007

The classical theory of electromagnetism is surveyed, with some emphasis on optics‐related topics. A brief historical introduction and summary is followed by a compilation of units and conventions in Sect. 2. Section 3 presents the Maxwell equations in differential and integral form. Section 4 treats the macroscopic Maxwell equations, constitutive relations, and the boundary conditions on these field variables at an interface between two different media. It also treats the simple dielectric and magnetic properties of matter. The causal nature of the response of matter to applied fields leads to the useful Kramers–Kronig dispersion relations, which can be generalized to nonlinear susceptibilities. Sections 5 and 6 are devoted to electromagnetic energy, its flow and conservation, and also to electromagnetic momentum. Section 7 concerns harmonic sources and their radiation fields. Section 8 is devoted to the properties of plane waves—transversality, phase and group velocities, linear and circular polarization, Stokes parameters, and the Fresnel formulas for reflection and refraction at an interface. Section 9 treats the theory of diffraction, first through the scalar theory of Kirchhoff and its improvements, and then with an example of a vector theory. Finally, Sect. 10 summarizes special relativity and shows how Maxwell's theory can be expressed as a covariant theory of electrodynamics.
Electron Diffraction
Authors: Cowley John M.
Published: August 2007

The diffraction of high‐voltage electrons (with energies of a few hundred keV) by small particles or thin films of solids shows many interesting analogies with diffraction phenomena for visible light and X rays. The electron wavelengths are about one hundred times smaller than the interatomic distances so that electrons show mostly forward scattering. The strong interaction with matter makes the scattering from single atoms detectable, and multiple scattering effects are common. In conjunction with electron microscopy, electron diffraction allows a detailed study of matter at the atomic level. Electron‐diffraction structure analysis, analogous to X‐ray crystallography, and studies of defects or local structural variations, may be applied to small particles or crystalline regions having dimensions in the nanometer range. High‐precision studies on electron distributions in bonds in small crystals are also possible. Many determinations have been made of the structures of the surface layers on crystals, and the diffraction by gases has added greatly to the knowledge of molecular structure.
Electro‐optic Devices
Authors: Maldonado Theresa A.
Published: August 2007

Electro‐optic devices can be designed to modulate various properties of a light wave, including phase, polarization, amplitude, frequency, and even its direction of propagation. Research over the years has focused on developing materials and complementary device geometries that together can yield desirable device performance for a large number of applications. This chapter provides an overview of the fundamental modes of operation for devices that alter the optical properties of materials in a controlled way for achieving light modulation. A mathematical treatment of light propagation in anisotropic and electro‐optically active media is presented to enable the device designer to quantify the modulation of light as well as the effects of slight misalignments of the structure on polarization and energy flow. Various classes of materials investigated for electro‐optic devices are presented; these include inorganic crystals, organic crystals, liquid crystals, semiconductors, and dye‐doped polymers. Possible device geometries include bulk, integrated optical waveguides, and optical fibers. In addition, performance criteria are defined, and a wide range of applications for these devices are summarized.
Electrophotographic Copying and Printing (Xerography)
Authors: Hays Dan A. , Ossman Kenneth R.
Published: August 2007

In the electrophotographic process for copying and printing documents, the image content controls the amount of light that selectively discharges a uniformly charged photoreceptor material. The electrostatic image is developed with a charged, pigmented powder that is transferred and bonded to paper with heat and pressure. Over the years, a variety of optical devices and systems have been used as electrophotographic technology has evolved to higher levels of performance and image quality. The earlier copiers utilized a light source and lens optical system to project the document image onto the charged photoreceptor. The imagers for copying use either optics with moving components or flash exposure systems. Electrophotographic printers do not use direct optical imaging but use a digital stream from an external source to generate a printed document. These printers were enabled by advances in digital electronics and light sources that exposed the photoreceptor with a scanning laser beam modulated by digital signals. Alternatively, many electrophotographic printers in recent years utilize a Light Emitting Diode (LED) array and optical lens array to imagewise expose the photoreceptor. An electrophotographic printer combined with an image input scanner becomes a digital copier that provides image editing, multiple copies from a single document scan, and digital image processing for high‐quality color documents. The advances in imaging devices over the last half century have played an important role in the current achievement of high‐quality color electrophotographic documents.
Fiber Optics
Authors: Nakahara Tsuneo , Tanaka Shigeru , Nishimura Masayuki
Published: August 2007

The optical fiber is one of the most important key technologies that support the current information technology (IT) era. Optical fibers are now widely used not only as an excellent transmission medium for optical communication but also as optical functional devices, such as optical amplifiers. Both optical fibers and their manufacturing technologies have evolved dramatically toward higher performance and improved productivity. Their applications have also been expanded from optical communication to a variety of fields, such as optical sensors. This article reviews various aspects of optical fibers: structures & materials, fabrication techniques, optical characteristics & reliability, and applications.
Fourier and Other Transform Methods
Authors: Bracewell Ronald N.
Published: August 2007

The Fourier transform is a basic tool for optical diffraction, interferometry, sky mapping, laser resonance, tomography, and other fields. Chemical analysis using Fourier transform spectroscopy and optical signal processing are traditional one‐dimensional applications, while in fiber‐optic transmission and optical analogue computing, the fractional Fourier transform is a new tool. Applications of other transforms (Abel, Hankel, Hartley, Radon) are also described. Mathematical definitions and properties are tabulated for reference.
Geometric Optics
Authors: Shack Roland
Published: August 2007

This article reviews the most elementary theory of optics, namely geometric optics, and describes its connection to quantum optics and other high‐level theories. The basics of light propagation in the form of rays and wave‐fronts are described. The main emphasis is on optical image‐forming systems and system aberrations. This article provides basic knowledge for any optical engineer.
Imaging Detectors
Authors: Blouke Morley M.
Published: August 2007

Charge‐coupled devices (CCDs) were first introduced in 1970 with the demonstration of an eight‐bit linear shift register. The concept of charge coupling was novel in the integrated circuit arena in that information was represented by discrete charge packets, which were manipulated in the device and, only at the output, converted to a voltage that could be measured. By operating in the charge domain, the charge‐coupled device is a true integrated circuit; it is impossible to make such a device from a collection of discrete components.

The serious development of Active Pixel Sensors began in the early 1990s, though their heritage hails from work done in the 1960s. Active pixel sensors get their name from the nature of the structure that makes up the pixel: a charge collection site and readout circuitry are provided within each pixel.

This article provides an overview of charge‐coupled devices and active pixel sensors, their design, structure, operation, and performance.
Interferometry
Authors: Hariharan Parameswaran , Creath Katherine
Published: August 2007

This article reviews the field of interferometry. It begins by outlining the fundamentals of two‐beam and multiple‐beam interference. The rest of the article discusses the applications of interferometry for measurement of length, optical testing, fringe analysis, interference microscopy, interferometric sensors, interference spectroscopy, nonlinear interferometers, interferometric imaging, space‐time and gravitation, holographic interferometry, Moiré techniques, and speckle interferometry. Each section provides a referenced (and cross‐referenced) overview of the application area.
Lasers, ExtremeUVand SoftX‐ray
Authors: Nilsen Joseph
Published: August 2007

Two decades ago, very large sources such as the building size ICF lasers were used as the energy sources to drive the first X‐ray lasers. Tremendous progress has been made over the last two decades to produce tabletop, high‐repetition rate X‐ray lasers that can be used as tools for applications. With the use of high‐reflectivity multilayer mirrors, many of the standard optical techniques such as interferometry can be extended to the soft X‐ray regime between wavelengths of 10 and 50 nm. The dominant X‐ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA) laser systems or capillary discharge. The CPA systems drive lasing in neon‐like or nickel‐like ions, typically in the 10‐ to 30‐nm range, while the capillary system is currently limited to driving neon‐like ions at a longer wavelength near 50 nm. Most researchers use nickel‐like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors, which have peak reflectivity near 13 nm, and are an essential component of applications such as X‐ray laser interferometry.
Linear Optics
Authors: Dorsel Andreas
Published: August 2007

This article gives a condensed overview of the key areas of linear optics, addressing fundamental aspects of light propagation and their application. After first principles like the speed of light and the laws of reflection and refraction, as well as the Fresnel formulas for transmission and reflection, total internal reflection, and linear absorption, geometric optics is briefly covered with the basic descriptions of imaging using simple mirrors and lenses. As examples of simple optical instruments, the single‐lens eye, the magnifier and microscope, as well as astronomical and terrestrial telescopes are included. Subsequently, phase‐dependent phenomena like interference and diffraction are described, including examples of a few basic cases that can be used to address more complex cases. Anisotropic media and polarization effects are covered next, including brief notes on electro‐optic, magneto‐optic, and acousto‐optic effects. Finally, examples of recent developments are described as an outlook to contemporary optics work.
Magneto‐optical Devices
Authors: Castera Jean Paul , Suzuki Takao
Published: August 2007

The history of magneto‐optical effects is first introduced. Then the types of magneto‐optical effects are described, which include the varieties of the interactions of electromagnetic waves with magnetization or spins in solids. The physical origin of the magneto‐optical effects is phenomenologically discussed. Both magnetic circular/linear birefringence and dichroism, and Void and Cotton–Mouton effects are discussed. Then, some representatives of magneto‐optical materials of transmission (Faraday effect) and reflection (Kerr) types are described. Finally, the applications of magneto‐optical effects are presented, which include the isolators, circulators, modulators, deflectors, magneto‐optical imaging, field sensors, magneto‐optical sensors, and magneto‐optical recording and microwave waveguides. In particular, a recent development of magneto‐optical recording is summarized, which highlights the various novel methods of increasing recording density.
Optical Communications
Authors: Kogelnik Herwig
Published: August 2007

This article discusses the fundamentals of optical fiber transmission technology and its basic building blocks. It aims to explain the principal characteristics of optical fibers, such as chromatic dispersion, of optical‐fiber amplifiers, including the noise they generate, and of semiconductor lasers. Also included is a discussion of optical receivers and their sensitivities, of nonlinear phenomena in optical‐fibers, of solitons, and of various transmission network architectures such as passive optical networks (PONs).
Optical Fabrication
Authors: Yi Allen Y.
Published: August 2007

Traditional optical fabrication processes utilize abrasive grinding, lapping to shape the glass optics and polishing to achieve an optical surface finish. The introduction of numerical control technology has resulted in higher productivity and better quality for glass optical fabrication. For medium‐ to high‐volume production, injection molding of aspherical plastic lenses is more economically feasible. Very recently, compression molding process has also emerged as a possible solution to high‐volume glass aspherical lens manufacturing. For low‐volume applications that include optical molds and high‐precision optics, special polishing techniques have been developed.
Optical Illusions
Authors: Hurlbert Anya
Published: August 2007

Visual illusions are tools with which vision scientists probe the visual system. Illusions are misperceptions of reality; some arise from limitations of the eye in image formation, and are rightly calledopticalillusions; some from neural adaptation, others from fundamental mechanisms of image reconstruction and interpretation that must operate even in the presence of inadequate, misleading, conflicting, or no sensory information. This chapter samples illusions of these different types in the perception of different visual attributes: lightness, color, size, shape, motion, and depth.
Optical Metrology
Authors: deGroot Peter
Published: August 2007

The article reviews the optical measurement of shape, texture, geometric dimensions, and position of objects, with applications ranging from stage metrology to optical comparators. An emphasis is placed on mechanical and geometric metrology, as opposed to remote sensing. The underlying technologies rely therefore on interferometry, triangulation, and time of flight to determine distances and lengths, as well as those object features accessible to length measurement, including, for example, form and roughness.
Optical Techniques for the Analysis and Characterization of Chemicals and Materials
Authors: Andrews David L.
Published: August 2007

Optical methods are widely used by industry, academia, medicine, and the military for the analysis and characterization of chemicals and materials. Prominent amongst these techniques are measurements based on infrared spectroscopy, ultraviolet and visible spectroscopy, molecular fluorescence, and Raman scattering. Microscopy and imaging procedures are also leading features in the analysis of heterogeneous samples, and a variety of laser‐based diagnostic methods are applied for specialized applications. In this account, the fundamental and technical issues for optical characterization are first examined, and then each of the major techniques is discussed in detail. Examples range from flame analysis to the determination of protein structures, surface optical nonlinearity, and chiral characterization.
Optical Techniques for Mechanical Measurement
Authors: Wykes Catherine
Published: August 2007

It is possible to measure a range of mechanical properties using light. These include presence, position, displacement, velocity, acceleration, surface form, and surface finish. This article summarizes the various methods and outlines the factors that limit their measurement performance. Representative values for commercially available systems are quoted where they are available and examples of applications are cited. The techniques discussed are presence detection, surface finish, optical triangulation, laser radar, interferometry, laser Doppler vibrometry and laser Doppler anemometry, electronic speckle pattern interferometry, holographic interferometry, moiré methods, and vision systems.
Optoelectronics
Authors: Kasap Safa O.
Published: August 2007

It is useful to view today's optoelectronics in terms of various functional categories, most important of which are the generation of light, modulation of light, transmission of light and its connection between devices, amplification of light, switching of light, isolation of light, filtering of light, wavelength multiplexing and demultiplexing of light, and detection of light. The corresponding devices that implement these functions are light emitters (or light sources), modulators, waveguides and connectors, optical amplifiers, optical switches, optical isolators, optical filters, multiplexers and demultiplexers, and detectors. This introductory article reviews the principles of operation and characteristics of a number of selected devices to provide a general introduction to the field of optoelectronics with an emphasis on optical communications—a major area of application.
Photography, Physics and Technology
Authors: Schuster Norbert
Published: August 2007

After 150 years of development in photography, everybody can take good snapshots to remember by. The physical relationships involved in obtaining a sharp and well‐illuminated picture are presented here. Fine mechanical, optical, and electronic elements all work together in a modern photographic camera. The three mostly commonly used types of cameras, the viewfinder type, the Single Lens Reflex type, and the professional bellows camera, are explained in detail. All three types are used with classical film as well as in digital still cameras.
Polarization Optics, Polarimeters and Polarization Spectrometers
Authors: Hermann Gerd
Published: August 2007

Polarimeters, employing polarization optics, are well known as highly precise and accurate instruments for determining optically active substances. Even simple manual polarimeters offer high accuracies compared to other analytical methods. Also, more sophisticated devices with half‐shadow adjustment and with quartz‐wedge compensation were already constructed in early times of polarimetry.

High improvement of polarimeters has been obtained with modern automated and semiautomated instruments. Until now, polarimetry has been the main analytical standard method for determining sucrose in the sugar and beverage industries and is an important tool for controlling production processes of optically active substances. For obtaining high precision and accuracy, the brightness and monochromaticity of the light source is important.

While polarimetry is based on intrinsic optical activity, polarization spectroscopy also measures anisotropies that may be induced into isotropic atomic or molecular species by DC electric or magnetic fields or also by interaction with radiation. Doppler‐free methods of nonlinear polarization spectroscopy yield high spectral resolution and result in the suppression of interferences by extremely close‐lying lines. Polarization spectroscopy based on an applied DC magnetic field, which is also denoted as coherent forward scattering spectroscopy (CFS), allows simultaneous multielement determination in combination with continuum light sources and the measurement over an extremely wide dynamic range.
Polarized Light, Basic Concepts of
Authors: Huard Serge J.
Published: August 2007

Polarization of light is a consequence of the vectorial nature of electromagnetic waves. This concept must be taken into account in a large number of optical phenomena such as birefringence, modulation of light, and propagation in optical devices. A representation of the states of polarization will first be analyzed. The propagation of light in linear or circular anisotropic media is carried out in the context of the phase velocity of the eigenstates of propagation. The evolution of a state of polarization traveling through a complex optical device will be finally presented.
Radiation Interaction with Molecules
Authors: Lombardi John R.
Published: August 2007

Various aspects of the interaction of electromagnetic radiation with matter are explored. The fundamental interaction involves the response of matter to electric and magnetic fields generated by the radiation. Any collection of charged particles will respond through its polarization
P
, which may be expanded in increasing powers of electric field
E
as
P
 = χ
(1)
E
 + χ
(2)
E
2
 + χ
(3)
E
3
. The term χ
(1)
is called the
linear susceptibility
(or more commonly the
polarizability
α), and is the term responsible for the linear refractive index as well as for linear absorption. The first order susceptibility is shown to be responsible for normal one‐photon spectroscopy, and we examine microwave, infrared, and optical spectroscopy as tools to obtain information as to the rotational, vibrational, and molecular orbital nature of molecules. Rydberg states, vibronic interactions, and magnetic resonance spectroscopy are also considered. χ
(2)
is the second‐order polarizability, sometimes called the
hyperpolarizability
β. This is responsible for hyper‐Rayleigh scattering and second‐harmonic generation, as well as the hyper‐Raman effect. These are often termed
two‐photon effects
owing to the quadratic dependence on the electric field. Three‐photon effects are obtained from the third‐order polarizability χ
(3)
or γ. Stimulated Raman spectroscopy and four‐wave mixing are some of the most important consequences of this term. These involve coherent anti‐Stokes Raman scattering (CARS) as well as Raman‐induced Kerr‐effect spectroscopy (RIKES).
Remote Sensing
Authors: Zalewski Edward F.
Published: August 2007

Remote Sensing is defined for space‐borne and airborne imaging instruments that use electromagnetic radiation. The historical background for this field of study is presented. The methods of remote sensing are described along with the portions of the electromagnetic spectrum that are utilized. The role of the atmospheric transmission limits and the corrections necessary for optimum accuracy is described. The different types electromagnetic detectors are described along with the image collection systems in which they are used. Modern remote sensing is possible because of the improvement in the accuracy of the radiometric calibration and characterization of the sensors and these methods are briefly described. The objective of remote sensing is the quantitative interpretation of the images, specifically obtaining the data products. Several examples of the basis for some of the data products are presented. Some of the remote sensing systems presently in use are briefly described. The future of remote sensing is described in terms of some of the planned sensors systems and the challenges that must be met in order to understand the Earth and mankind's effect on its climate.
Spectrometers, Infrared
Authors: Kauppinen Jyrki K. , Hollberg Matti R. , Keens Axel
Published: August 2007

This paper is a review‐type article dealing with infrared (IR) spectrometers and their applications. The paper represents general aspects of IR spectrometry and general principles of IR spectrometers. Performance properties of IR spectrometers and especially detectors are defined and described. More detailed descriptions are given for prism, grating, Fourier transform (FT), and laser spectrometers. Because nowadays most of the IR spectra are recorded by FT‐IR spectrometers, the main attention of the paper is aimed at FT‐IR instruments. The advantages of FT spectrometers as compared with grating spectrometers are also demonstrated. The paper gives a large number of typical examples of applications of FT‐IR spectrometers in science and practical analysis.
Spectroscopy, Ultrafast
Authors: Dantus Marcos , Gross Peter
Published: August 2007

Spectroscopy studies the interaction between light and matter. Ultrafast spectroscopy involves the study of this interaction using temporally short light pulses capable of probing directly the dynamics of the system rather than its energy levels. Rapid advances in laser technology over the past decades have resulted in the generation of pulses with femtosecond time duration (1fs = 10−15 s). These lasers are being used to interrogate solids, liquids, and gases to learn about the dynamics of matter (electrons, atoms, molecules) following laser excitation. The description given here explains how an ultrashort laser pulse excites a coherent superposition of energy levels, and how this excitation can be followed in time. To date, ultrafast spectroscopy has been used to measure processes in diverse fields, for example, to measure the time it takes to break or form a chemical bond; to measure the temporal response of molecules involved in photosynthesis, or vision; and to measure the flow of charge in semiconductors. Examples of these kinds of studies illustrate this presentation.