scholarly journals Interferometric measurement of the temperature coefficient of the refractive index dn/dT and the coefficient of thermal expansion of Pr:YLF laser crystals

2014 ◽  
Vol 22 (25) ◽  
pp. 30683 ◽  
Author(s):  
Orestis S. Kazasidis ◽  
Ulrich Wittrock
Keyword(s):  
Refractive Index ◽  
Thermal Expansion ◽  
Temperature Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Interferometric Measurement ◽  
Laser Crystals

scholarly journals A Proposal for a Composite with Temperature-Independent Thermophysical Properties: HfV2–HfV2O7

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5021
Author(s):  
Philipp Keuter ◽  
Anna L. Ravensburg ◽  
Marcus Hans ◽  
Soheil Karimi Aghda ◽  
Damian M. Holzapfel ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Temperature Coefficient ◽  
Thermophysical Properties ◽  
Coefficient Of Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Phase Fraction ◽  
Formation Temperature ◽  
Oxygen Mobility ◽  
Zero Temperature ◽  
Coefficient Of Elasticity

The HfV2–HfV2O7 composite is proposed as a material with potentially temperature-independent thermophysical properties due to the combination of anomalously increasing thermoelastic constants of HfV2 with the negative thermal expansion of HfV2O7. Based on literature data, the coexistence of both a near-zero temperature coefficient of elasticity and a coefficient of thermal expansion is suggested for a composite with a phase fraction of approximately 30 vol.% HfV2 and 70 vol.% HfV2O7. To produce HfV2–HfV2O7 composites, two synthesis pathways were investigated: (1) annealing of sputtered HfV2 films in air to form HfV2O7 oxide on the surface and (2) sputtering of HfV2O7/HfV2 bilayers. The high oxygen mobility in HfV2 is suggested to inhibit the formation of crystalline HfV2–HfV2O7 composites by annealing HfV2 in air due to oxygen-incorporation-induced amorphization of HfV2. Reducing the formation temperature of crystalline HfV2O7 from 550 °C, as obtained upon annealing, to 300 °C using reactive sputtering enables the synthesis of crystalline bilayered HfV2–HfV2O7.

Determination of Refractive Indices and Linear Coefficients of Thermal Expansion for Development of Athermal Glass

2011 ◽  
Vol 675-677 ◽  
pp. 1113-1116
Author(s):  
Yoshinao Kobayashi ◽  
Taiichi Shimizu ◽  
Rie Endo ◽  
Masahiro Susa
Keyword(s):  
Refractive Index ◽  
Thermal Expansion ◽  
Temperature Dependence ◽  
Path Length ◽  
Sessile Drop ◽  
Coefficient Of Thermal Expansion ◽  
Optical Path Length ◽  
Optical Path ◽  
Linear Coefficient ◽  
Optical Fibre Transmission

Recently, there has been a growing importance of development of ‘athermal glass’ having no temperature dependence in its optical path length and is expected to be used in optical devices for the optical fibre transmission system. The athermal characteristic is usually evaluated by temperature dependence of optical path length, (1/l)･(dS/dT) ( l : geometrical length, S : optical path length, T : temperature), which is the summation of nα and dn/dT (n: refractive index, α: linear coefficient of thermal expansion). In the present work, the refractive index and liner coefficient of thermal expansion have been determined for silicate glasses containing titanium oxides in the temperature range from room temperature to about 673 K, using ellipsometry and utilizing the sessile drop method. The values of nα and temperature coefficient of n ranged from 1.289×10-5 K-1 to 3.345×10-5 K-1 and from 0.270×10-5 K-1 to 1.467×10-5 K-1, respectively, depending on the glass composition. Consequently, only 80SiO2-5TiO2-15Na2O glass has shown almost the same degree of athermal characteristic as SiO2 glass, having more advantages in practice due to its lower melting temperature than SiO2.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XVI. DENSITY, OPTICAL ROTATORY POWER, AND REFRACTION OF AQUEOUS 2,3-BUTANEDIOL SOLUTIONS

1946 ◽  
Vol 24b (6) ◽  
pp. 269-279 ◽  
Author(s):  
K. A. Clendenning
Keyword(s):  
Refractive Index ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Rotatory Power ◽  
Specific Rotation ◽  
Optical Rotatory ◽  
Meso Form ◽  
Refractive Index Data ◽  
Lines Of Evidence ◽  
Optical Rotatory Power

Addition of water to the levo- and meso-isomers of 2,3-butanediol increases the specific gravity to a maximum at 50 to 60% diol, beyond which it is gradually reduced. Contraction on mixing is strongly influenced by temperature and is slightly greater with the levo- than with the meso-isomer. The coefficient of thermal expansion for the levo-isomer is higher than that of the meso-form. Water exerts a pronounced influence on the specific rotation value of the levo-isomer, reducing it from − 13° (anhydrous) to approximately − 9° for solutions containing 40 to 70% water; on further dilution, the specific rotation value rises. With increase in temperature, the optical rotatory power of the anhydrous levo-isomer is reduced, whereas that of 30 to 90% aqueous solutions is increased. Refractive index data are provided for aqueous meso-2,3-butanediol solutions at 25 °C. and for aqueous levo-2,3-butanediol solutions at 20°, 25°, 30°, and 35 °C. From several lines of evidence it is concluded that the hydration tendencies of the two isomers are approximately equivalent.

The measuring approach of the nonlinear high-temperature coefficient of thermal expansion during isothermal cooling

Measurement ◽  
2020 ◽  
Vol 159 ◽  
pp. 107766
Author(s):  
Zujun Peng ◽  
Weihua Xie ◽  
Songhe Meng ◽  
Xinxing Han ◽  
Hongyue Wang ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Temperature Coefficient ◽  
Coefficient Of Thermal Expansion
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