Table 1: Comparison of basic properties between silica and ZBLAN glasses [2028].

Glass propertySilicaZBLAN

Approximate transmission range (1 mm thickness, ) ( m)0.16–4.00.22–8.0
Maximum phonon energy (cm-1)1100600
Transition temperature (°C)1175260
Specific heat (J/(g K))0.1790.151
Thermal conductivity, W/(m·K)1.380.628
Expansion coefficient (10-6/K)0.5517.2
Density (g/cm3)2.204.33
Knoop hardness (kg/mm2)600225
Fracture toughness (MPam1/2)0.720.32
Poisson’s ratio0.170.17
Young’s modulus (Gpa)7058.3
Shear’s modulus (Gpa)31.220.5
Bulk’s modulus (Gpa)36.747.7
Refractive index (@ 0.589 um)1.4581.499
Abbe number6876
Zero material dispersion wavelength ( m)1.31.6
Nonlinear index (10-13 esu)10.85
Thermo-optic coefficient (10-6/K)11.9−14.75