Electro-optics

The principle of optical triangulation has been known since the time of the early Greeks, and indeed optical triangulation has been used for hundreds of years in applications such as surveying, camera auto-focus and even smart-bombs. With the advent of low-cost, compact electro-optic components such as lateral-effect photodetectors, diode lasers and micro-optics, laser-based triangulation sensors can now be employed for applications that were, heretofore, considered uninspectable. 

Figure Cl.4.9. Usual cooling (carrier) and repumping (sideband) transitions when optically cooling Na atoms. The repumper frequency is nonnally derived from the cooling transition frequency with electro-optic modulation.

Sharpness. This describes the steepness of the electro-optical switching as a function of voltage. This is defined in tenns of the ratio of voltages required to achieve 90% compared to 10% transmission of light. This ratio should be as close to unity as possible. 

Blinov L M 1983 Electro-optical and Magneto-optical Properties of Liquid Crystals (Chichester Wiley)... 

Clark N A and Lagerwall S T 1980 Submicrosecond bistable electro-optic switching in liquid crystals App/. Phys. Lett. 36 899-901... 

Clark N A, Handschy M A and Lagerwall S T 1983 Ferroelectric liquid crystal electro-optics using the surface stabilized structure Molec. Cryst. Liq. Cryst. 94 213-34... 

Porschke D and Obst A 1991 An electric field jump apparatus with ns time resolution for electro-optical measurements at physiological salt concentrations Rev. Sc/. Instnim. 62 818-20... 

PT, PZT, PLZT nonvolatile memory, ir, pyroelectric detectors, electro—optic waveguide, and spatial light modulators sol—gel, sputtering... 

Certain glass-ceramic materials also exhibit potentially useful electro-optic effects. These include glasses with microcrystaUites of Cd-sulfoselenides, which show a strong nonlinear response to an electric field (9), as well as glass-ceramics based on ferroelectric perovskite crystals such as niobates, titanates, or zkconates (10—12). Such crystals permit electric control of scattering and other optical properties. 

D. C. Nguyen and co-workers. Paper CThNl, 1993 Conference on Lasers and Electro-Optics, Baltimore, Md., May 2—7,1993. 

W. D. Rogatto, "Electro-Optics Components," inj. S. Accetta andD. L. Shumaker, eds.. The Infrared Electro-Optical Systems Handbook, Vol. 3, SPIE Optical Engineering Press, Bellingham, Wash., 1993. 

Circular dichroism employs standard dispersive or interferometric instmmentation, but uses a thermal source that is rapidly modulated between circular polari2ation states using a photoelastic or electro-optic modulator. Using phase-sensitive detection, a difference signal proportional to the absorption difference between left- and right-polari2ed light, AA is recorded as a function of wavenumber. Relative differential absorptions... 

Barium sodium niobium oxide [12323-03-4] Ba2NaNb 02, finds appHcation for its dielectric, pie2oelectric, nonlinear crystal and electro-optic properties (35,36). It has been used in conjunction with lasers for second harmonic generation and frequency doubling. The crystalline material can be grown at high temperature, mp ca 1450°C (37). 

The cyanine class of dyes is also useful in biological, medical, laser, and electro-optic appHcations. Dyes marketed as Povan [3546-41-6] (5) and Dithiazanine [7187-55-5] (6) are useful anthelmintics, and Indocyanine Green [3599-32-4] (7) is an infrared-absorbing tracer for blood-dilution medical diagnoses. "Stains-AU." is a weU-studied biological stain (8) and Merocyanine 540 s photochemotherapeutic activity is known in some detail (9). Many commercially available red and infrared laser dyes are cyanines (10). 

M. Okawata, T. Kitao, T. Hirashima, and M. Matsuoka, Organic Colorants A Handbook of Selected Dyesfor Electro-Optical Applications, Elsevier, Amsterdam and New York, 1988. 

Liquid crystal display systems have been increasingly used in electro-optical devices such as digital watches, calculators, televisions, instmment panels, and displays of various kinds of electronic equipment, ie, lap-top computers and word processors. The dominant reason for thek success is thek extremely low power consumption. Furthermore, the Hquid crystal display systems have been remarkably improved in recent years, and today they have high resolution (more than 300,000 pixels) and full color capabiUty almost equivalent to those of a cathode ray tube. 

In lead zh conate, PbZrOs, the larger lead ions are displaced alternately from the cube corner sites to produce an antifeiToelectric. This can readily be converted to a feiToelectric by dre substitution of Ti" + ions for some of the Zr + ions, the maximum value of permittivity occumirg at about the 50 50 mixture of PbZrOs and PbTiOs. The resulting PZT ceramics are used in a number of capacitance and electro-optic applicahons. The major problem in dre preparation of these solid soluhons is the volatility of PbO. This is overcome by... 

The main categories of electrical/optical ceramics are as follows phosphors for TV, radar and oscilloscope screens voltage-dependent and thermally sensitive resistors dielectrics, including ferroelectrics piezoelectric materials, again including ferroelectrics pyroelectric ceramics electro-optic ceramics and magnetic ceramics. 

Model Curriculum for Training Asbestos Abatement Contractors and Supervisors. Safety Health and Ergonomics Branch Electro-Optics, Environment, and Materials Laboratory, U.S. Environmental Protection Agency Cooperative Agreement No. CX 820760-010-0, pp. X-6, X-7, X-8. 

Elektroofen, m. electric furnace, elektrooptisch, a. electro-optic. 

On the other hand, fluorine s high electronegativity and its ability to form mostly ionic chemical bonds, provide materials with several useful properties. First, compared to oxides, fluoride compounds have a wide forbidden zone and as a result, have low electroconductivity. In addition, fluorides are characterized by a high transparency in a wide optical range that allows for their application in the manufacturing of electro-optical devices that operate in the UV region [42,43]. 

Crystals with one of the ten polar point-group symmetries (Ci, C2, Cs, C2V, C4, C4V, C3, C3v, C(, Cgv) are called polar crystals. They display spontaneous polarization and form a family of ferroelectric materials. The main properties of ferroelectric materials include relatively high dielectric permittivity, ferroelectric-paraelectric phase transition that occurs at a certain temperature called the Curie temperature, piezoelectric effect, pyroelectric effect, nonlinear optic property - the ability to multiply frequencies, ferroelectric hysteresis loop, and electrostrictive, electro-optic and other properties [16, 388],... 

Experiments on transport, injection, electroluminescence, and fluorescence probe the spatial correlation within the film, therefore we expect that their response will be sensitive to the self-affinity of the film. This approach, which we proved useful in the analysis of AFM data of conjugated molecular thin films grown in high vacuum, has never been applied to optical and electrical techniques on these systems and might be an interesting route to explore. We have started to assess the influence of different spatial correlations in thin films on the optical and the electro-optical properties, as it will be described in the next section. 

Jenngins, B. R. Electro-Optic Methods for Characterizing Macromolecules in Dilute Solution. Vol. 22, pp. 61—81. 

Electro-optic The liquid crystal plastics exhibit some of the properties of crystalline solids and still flow easily as liquids (Chapter 6). One group of these materials is based on low polymers with strong field interacting side chains. Using these materials, there has developed a field of electro-optic devices whose characteristics can be changed sharply by the application of an electric field. 

This photoelastic stress analysis is a technique for the nondestructive determination of stress and strain components at any point in a stressed product by viewing a transparent plastic product. If not transparent, a plastic coating is used such as certain epoxy, polycarbonate, or acrylic plastics. This test method measures residual strains using an automated electro-optical system. 

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