Optical materials synthetic quartz

Oscillators -NLO for lasers [NONLINEAR OPTICAL MATERIALS] (Vol 17) -parametric [LASERS] (Vol 15) -synthetic quartz crystals for [SILICA - SYNTHETIC QUARTZ CRYSTALS] (Vol 21)... 

As a result, cuvettes for Raman spectroscopy should be carefully selected. They may, due to their impurities, add a background to the spectrum of the sample. In addition, all cuvette materials produce their own Raman spectra, which have to be considered, when the Raman spectra of the sample are evaluated. Fig. 3.5-17 a shows a Raman spectrum of a typical optical glass BK7, Fig. 3.5-17 b that of quartz glass suprasil, and Fig. 3.5-17 c of sapphire. Suprasil is a synthetic quartz which does not normally contain impurities. Therefore, Suprasil of ESR quality is highly recommended as Raman cuvette material. Also, sapphire is a good cuvette material, as it is very hard, inert, has a good thermal conductance, and shows only weak but sharp Raman lines (Porto and Krishnan, 1967). It is used for the production of the universal Raman cell (Schrader, 1987). The sharp Raman lines of sapphire observed in the spectra of the sample may be subtracted from the spectrum or used as internal standard for quantitative analyses (Mattioli et al, 1991). 

Measuring cuvettes, in which sample solutions are placed, are made of various materials depending on the range of radiation used in the measurement. Measurements in the UV are performed with the use of quartz cuvettes. Synthetic quartz, which is less contaminated with traces of metals, has better optical properties. Measurements in the VIS range are made using quartz, glass, or plastic cuvettes. 

An example of the way in which AFM has been applied to inorganic material surfaces is provided by the study of Gratz et al. [250] on the dissolution of quartz in potassium hydroxide solution. Such a study forms part of a general attempt to understand the phenomena of the dissolution and growth of crystal surfaces, either of natural origin or grown synthetically. The authors etched optical-quality natural quartz for 4 h at 148°C in KOH solution and then examined the surface with AFM, in this case in ethanol, which was found to keep the surface clean. Quartz is an insulator and could not therefore be studied by STM. 

Optical fibers are often used for NIR spectroscopy, as mentioned later. Synthetic quartz is mainly used as the material for these fibers. Since the NIR light for measurements is often required to travel a long distance through a fiber, special attention has to be paid to make... 

Several gemstone species occur in various colors, depending on the presence of impurities or irradiation-induced color centers. Examples are the beryl, corundum, and quartz families. Quartz has poor optical properties (RI = 1.55, DISP = 0.013), but becomes of gemological interest when it exhibits attractive colors. Any material can have its color modified by the addition of various impurities synthetic mby, sapphires, and spind are produced commercially in over 100 colors (2). Synthetic cubic zirconia has been made in essentially all colors of the spectrum (11), but only the colorless diamond imitation is produced commercially in any quantity. 

Synthetic, pure, quartz, SiO glass (also known as fused quartz) does not absorb UV radiation above approximately 150 nm. Because of its high transparency, melting temperature and resistance to corrosion, it is the material of choice for UV optical components and as an envelope material. 

Silica, the main component of silicates, is widely used as mentioned earlier. In its crystalline and noncrystalline polymorphs, silica is used industrially as a raw material for glasses, ceramics, foundry molds, in the production of silicon, and more recently in technical applications such as quartz oscillators and optical waveguides for longdistance telecommunications. Of the crystalline forms, only a-quartz is commonly used as sand or as natural and synthetic single crystals. Cristobalite is often utilized as the synthetic phase in glass-ceramics. 

It is important to understand that plane-polarized light can be produced both naturally (calcite and quartz crystals) and synthetically (with aligned polymers [Chapter 6]), and when such polarized light passes through chiral ( handed ) materials (or solutions of chiral materials), the plane of polarization is rotated. Historically, this property has been called optical rotation, and the chiral material was said to be optically active. Indeed, experimentally, the rotation of the plane of plane-polarized light demonstrates optical activity and thus, that the material is chiral. 

While glasses, natural and synthetic crystals, and semiconductors provide at least several choices for the design of optical components in the near and middle infrared, suitable bulk materials are more limited at longer wavelength. Quartz,... 

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