scholarly journals Measurement of linear coefficient of thermal expansion and temperature-dependent refractive index using interferometric system

2017 ◽  
Author(s):  
James A. Corsetti ◽  
William E. Green ◽  
Jonathan D. Ellis ◽  
Greg R. Schmidt ◽  
Duncan T. Moore
Keyword(s):  
Refractive Index ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Temperature Dependent ◽  
Linear Coefficient

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.

Extraction of the Coefficient of Thermal Expansion of Thin Films from Buckled Membranes

1998 ◽  
Vol 546 ◽  
Author(s):  
V. Ziebartl ◽  
O. Paul ◽  
H. Baltes
Keyword(s):  
Thin Films ◽  
Finite Element ◽  
Thermal Expansion ◽  
Silicon Nitride ◽  
Excellent Agreement ◽  
Energy Minimization ◽  
Coefficient Of Thermal Expansion ◽  
Temperature Dependent ◽  
Minimization Method ◽  
Energy Minimization Method

AbstractWe report a new method to measure the temperature-dependent coefficient of thermal expansion α(T) of thin films. The method exploits the temperature dependent buckling of clamped square plates. This buckling was investigated numerically using an energy minimization method and finite element simulations. Both approaches show excellent agreement even far away from simple critical buckling. The numerical results were used to extract Cα(T) = α0+α1(T−T0 ) of PECVD silicon nitride between 20° and 140°C with α0 = (1.803±0.006)×10−6°C−1, α1 = (7.5±0.5)×10−9 °C−2, and T0 = 25°C.

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