Refractive index modification

Taguchi A, Hayazawa N, Saito Y, Ishitobi H, Tarun A, Kawata S (2009) Controlling the plasmon resonance wavelength in metal-coated probe using refractive index modification. Opt Exp 17 6509... 

Recently systematic studies of the surface properties of glass and other insulators have been made after bombardment with ions in the 40 to 100 keV range. Refractive index modifications were observed which are caused by phase changes, micropo-... 

Refractive index modifications. An ideal material for many holographic applications must be capable of recording the information as variations of the index of refraction throughout its volume in order to achieve diffraction efficiencies up to 100%. 

Townsend et al. (1989) bas studied directional couplers made from poly-4BCMU spun film deposited on a patterned with two channels substrate. At 1.064 Mm operation wavelength they observed nonlinear transmission and switching from one channel to another one both due to a fast (ps) electronic and slow thermal nonlinearities. However the fast switching was due to the refractive index modification via the two photon absorption. 

The schlieren microscope is able to detect refractive index variations to six decimal places. Any small difference in optical path (index difference, film thickness, etc) is very precisely detected by the schlieren microscope, especially in the Dodd modification. It is, in effect, a darkfield method. The specimen is illuminated with light in a portion of the illuminating cone and that direct light is masked in the conjugate back focal plane of the objective (Fig. 3). The only light to pass through this plane is refracted, reflected, or diffracted by the specimen. 

Chemical modification of the wax can improve smear resistance (5). Sihcones, which do not harm furniture finishes (6), are incorporated as film-forming ingredients in furniture pohshes. The lubricant properties of sihcones improve ease of apphcation of the pohsh and removal of insoluble soil particles. In addition, sihcones make dry films easier to buff and more water-repeUent, and provide depth of gloss, ie, abihty to reflect a coherent image as a result of a high refractive index (7). Wax-free pohshes, which have sihcones as the only film former, can be formulated to dehver smear resistance (8). Another type of film former commonly used in oil-base furniture pohshes is a mineral or vegetable oil, eg, linseed oil. 

Henderson and Sutherland have prepared a hydrocarbon synthetically which is possibly a modification of terpinene. They reduced thymo-hydroquinone, thus obtaining menthane-2-5-diol, which was heated for half an hour with twice its weight of sulphate of potash under a reflux condenser, and so yielded a terpene boiling at 179°, of specific gravity about 0 840 and refractive index 1-4779. 

Both recycled and non-recycled essential oils met the standards for specific gravity, angular rotation and refractive index of the Food Chemicals Codex [22] and United States Pharmacopeia [23] for cold-pressed lemon peel oil. Results of gas chromatography analysis show the same compounds and levels in both systems, specially for the oxygenated compounds as citral (neral and geranial). Therefore, recycling the aqueous discharges to the extractor does not cause undesirable modifications. 

Ishaq, I. M. Quintela, A. S. James, W. Ashwell, G. J. Lopez Higuera, J. M. Tatam, R. P., Modification of the refractive index response of long period gratings using thin film overlays,... 

Occurs as colorless orthorhombic modifications, valentinite, or colorless cubic form, senarmontite density 5.67 g/cm (valentinite), 5.20g/cm3 (senar-montite) cubic modification is dimeric consisting of Sb20e discrete molecules refractive index 2.087 melts in the absence of oxygen at 656°C boils at 1,550°C (sublimes) sublimes in vacuum at 400°C very slightly soluble in water, insoluble in organic solvents soluble in HCl, caustic alkalies and tartaric acid. 

Only the TiOz anatase crystal modification is formed on the mica surface. Small amounts of Sn02 are, therefore, used to catalyze conversion to the rutile structure with its higher refractive index, brilliance, color intensity, and superior weather and light resistance [5.192]-[5.194]. 

The light-scattering apparatus and procedure have been formerly described (15). The only modification and precaution with polybutadienes were to use the appropriate refractive index differential for each polymer as this was observed to decrease with vinyl content values used were 0.118, 0.112, and 0.106 dl/gram for 2, 10, and 20% vinyl polybutadienes in cyclohexane at 25 °C and 546 m//,. 

Another plasmon resonance approach for detection of mercury vapour is based on localized plasmon resonance in gold nanoparticles deposited on transparent support (Fig. 12.4, right). Changes of the refractive index of gold nanoparticles due to adsorption of mercury should lead to modification of the gold plasmon band of optical adsorption spectra. This approach has been applied successfully for investigation of interaction of biomolecules however, to our knowledge there is still no report on its applications for detection of mercury vapour. 

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