Measurement of refractive indices of 20 optical materials at low temperatures

2006 ◽  
Vol 45 (8) ◽  
pp. 083401 ◽  
Author(s):  
Shuji Sato
2018 ◽  
Vol 879 ◽  
pp. 227-233
Author(s):  
Weeratouch Pongruengkiat ◽  
Thitika Jungpanich ◽  
Kodchakorn Ittipornnuson ◽  
Suejit Pechprasarn ◽  
Naphat Albutt

Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.


1965 ◽  
Vol 18 (7) ◽  
pp. 959 ◽  
Author(s):  
WJ Asker ◽  
AW Wylie

Pure anhydrous cerium tetrafluoride is best prepared by fluorinating cerium dioxide at 350-500�. A monohydrate can be obtained from aqueous solution in a variety of ways, but it cannot be dehydrated without decomposition. It loses water "zeolitically" in vacuum, showing relatively small changes in lattice parameters for loss of 70% of its water content. Thereafter the lattice collapses, forming well-crystallized cerium trifluoride and poorly crystallized "anhydrous" cerium tetrafluoride. The refractive indices of anhydrous monoclinic cerium tetrafluoride have been measured and its fluorine dissociation pressure at 500� shown to be less than 0.5 mm. At higher temperatures the tetrafluoride sublimes incongruently, and at 835-841� it melts with extensive decomposition into a fluorine-poor liquid and a fluorine-rich vapour. Cerium tetrafluoride is easily reduced to the trifluoride by ammonia and by water vapour at low temperatures. At higher temperatures it is quantitatively converted by water vapour to cerium dioxide and hydrogen fluoride. When heated with cerium dioxide it is reduced to the trifluoride with liberation of oxygen.


2017 ◽  
Vol 31 (29) ◽  
pp. 1750263 ◽  
Author(s):  
Tao Zhang

The theoretical calculation of the refractive indices is of great significance for the developments of new optical materials. The calculation method of refractive index, which was deduced from the electron-cloud-conductor model, contains the shape and direction factor [Formula: see text]. [Formula: see text] affects the electromagnetic-induction energy absorbed by the electron clouds, thereby influencing the refractive indices. It is not yet known how to calculate [Formula: see text] value of non-spherical electron clouds. In this paper, [Formula: see text] value is derived by imaginatively dividing the electron cloud into numerous little volume elements and then regrouping them. This paper proves that [Formula: see text] when molecules’ spatial orientations distribute randomly. The calculations of the refractive indices of several substances validate this equation. This result will help to promote the application of the calculation method of refractive index.


2005 ◽  
Vol 44 (10) ◽  
pp. 3589-3593 ◽  
Author(s):  
Xavier Rocquefelte ◽  
Fabrice Goubin ◽  
Yvan Montardi ◽  
Nicolas Viadere ◽  
Alain Demourgues ◽  
...  

ChemInform ◽  
2005 ◽  
Vol 36 (28) ◽  
Author(s):  
Xavier Rocquefelte ◽  
Fabrice Goubin ◽  
Yvan Montardi ◽  
Nicolas Viadere ◽  
Alain Demourgues ◽  
...  

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