Optical filters/materials

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

Optics Electrochromic displays, optical filters (windows with adjustable transparency), materials with non-linear optical properties... 

Among all semiconductor NPs, metal selenides have been the focus of great attention due to their importance in various applications such as thermoelectric cooling materials, optical filters and sensors, optical recording materials, solar cells, superionic materials, laser materials and biological labels. Many synthetic methods have been developed for the preparation of relatively monodispersed selenide nanopartides (Murray et al., 1993 Korgel... 

By the sol-gel-process, inorganic glassy and hybrid polymeric materials are accessible at comparatively low temperatures [1], Therefore, organic molecules or dyes can easily be incorporated into the oxide matrix. This combination is especially attractive for the development of the following devices optical filters, solid-state lasers, optical switches, nonlinear optical laser hosts, optical data storage media, and photoconductive devices and films [2]. 

Visible- or solar-blind UV sensors can be made from a Si photodiode by additionally using an optical filter that transmits UV radiation only, see below. A more detailed explanation of the physics of UV photodiodes (made from Si as well as from other semiconductor materials) can be found in Ref. [1]. 

I tjzoIo[ 1,5-/] [1,2,4] triazole azomethines were investigated and used for manufacturing of inks, optical filters, thermal transfer printing materials, and toners. Some of them were prepared and formulated into a water-thinned jet printing ink <2002JAP256164, 2000EUP1035172>. 

Figure 11.15. Schematics of the optical arrangement and temperature probes for the Cr+ fluorescence lifetime-based fiber optic thermometers. F = short-pass optical filter Fa = bandpass or long-pass optical filter LD = laser diode LED = light emitting diode S = the fluorescence material used as sensing element vm = signal to modulate the output intensity of the excitation light source v/= the detected fluorescence response from the sensing element.

An optical material has an absorption coefficient of 10 cm at 400 nm. (a) What thicknes s of material must you cut to fabricate an optical filter with optical density of 3 at 400 nm (b) If you have a laser of 1 W power at this wavelength but you... 

J. C. Travis and G. W. Kramer, NIST-traceable-reference-material optical filters program for chemical spectrophotometry, Spectroscopy, 14(2), 1999. 

The fundamental elements of an ultraviolet-absorption analyzer include (a) a radiation source (b) suitable optical filters (c) a sample cell and (d) an output meter. A transmittance measurement is made by calculating the ratio of the reading of the output with die sample in the cell to die reading widi the cell empty (of ultraviolet-absorbing materials). The concentration can be calculated from the known absorptivity of the substances as previously demonstrated by the equations or it may be determined by comparison with known samples. 

Transmittance > 6 mm Higher than Other Material Microwave Windows, Optical Filters, Optical Waveguides... 

In general, metal oxides are very common inorganic commodities, widely applied, and display an assortment of unique chemical and physical properties. They are accessible by different techniques including chemical vapor deposition and sol-gel methods. Their technological application extends from super- and semiconducting materials to electrochromic devices, optical filters, protective coatings and solar absorbers ... 

This procedure is very time-consuming and may be speeded up materially if a small amount of one of the pure components (a seed ), preferably the less soluble one, is available. If a slightly supersaturated solution that is reasonably free from dust and other particles is prepared, nucleation usually occurs slowly. If a seed is now added, the rate at which the component which is seeded will crystallize wDl be markedly greater than that of the other component and if the solution is filtered soon after most of the initial crystallization has occurred, it will often be found that the solid contains mainly the component which was seeded. A good example of this is found in the separation of the isomers of methvlethylisobutylcarbinyl acid phthalate as the brucine salt. In the first separation, 20 recrystallizations of the head fraction were required in order to obtain optically pure material. By using a small amount of this material as a seed, optically pure material was later obtained after about seven cr stallizations. 

By far the most important application fields for inorganic fibers are the insulation and reinforcing sectors. Fibers are also used as fillers and as filter materials. As with other materials, functional properties such as electrical, optical or magnetic properties are becoming increasingly important for fibers, in addition to mechanical and electrical properties. 

Side-chain LCPs can be prepared by attaching a mesogen pendant to a flexible polymer backbone (18). These materials often have optical properties similar to low molar mass LCs and have generated interest for such applications as non-linear optics, filters and optical storage devices. 

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