Light conductivity

In this type of Microscopy a fine beam of electrons is scanned across the surface of an opaque specimen to which a light conducting film has been applied by evaporation. Secondary electrons, backscattered elections, or (in the electron microprobe)... 

A study was made of the effects of processing conditions and of blowing and nucleating agents and external lubricants on the apparent density, mechanical properties, linear thermal expansion coefficient and surface roughness of extruded cellular MDPE. Based on the results, recommendations were formulated for the properties of cellular MDPE pipes for the protection of light conducting cables. 16 refs. (Translation of Polimery, Tworzywa Wielkoczasteczkowe, No. 10, 1996, p.580). 

Figure 12.7. Schematic of the n-around-1 unhltered fiber-optic probe. The excitation and collection fibers need not be the same diameter, but usually are. The inset shows a photo of an 18-around-l probe illuminated with white light conducted from the spectrometer end of the fiber cable. (Adapted from Reference 5).

Selenium has excellent light-conducting and light-converting properties. Until the 1970s, selenium semiconductors were more el3 cient than the previously used copper oxide rectifiers but could not stand the competition when cheaper silicon diodes came on the market. Now nearly all rectifiers are made with silicon components. Selenium is, however, currently enjoying a resurgence of interest as a possibly important component in electronics for solar cells. 

LISA Polycarbonate-based light conducting polymers Bayer AG/Miles... 

Preparation of samples is in most cases unnecessary. What is needed are flexible fiber optic cables for light conduction, adapters and optical measuring heads. 

Figure 4-56. Light conduction by total reflection in a monofiber.

Figure 8.2. Light conduction by multiple total reflection in a single optical flbre. Incident light is accepted only inside a cone with the maximum incident angle 6max...

Preferred materials for light guides are fused silica, glasses or specific polymers. The latter are cheap and can be manufactured easily. If sensor use is restricted to visible light, polymer fibres are sufficient commonly. Fused silica is characterized by maximum spectral transparency and thus useful for light conduction over long distances. 

A light conducting polymeric material with A d = 11% may be obtained by impregnation of the polymer with microcavities by a resin (the refractive index of which is much higher than that of the matrix polymer) [44], and with further thermal curing. The initial polymer with microcavities is obtained by UV-radiation of a mixture of the polymer and the monomer (for example, PMMA-MMA, i.e. components identical in chemical structure) through a hollow gage. 

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