High-Power ZBLAN Glass Fiber Lasers: Review and Prospect

Table 1

Comparison of basic properties between silica and ZBLAN glasses [20–28].

Glass property	Silica	ZBLAN
Approximate transmission range (1 mm thickness, 𝑇>10%) (𝜇m)	0.16–4.0	0.22–8.0
Maximum phonon energy (cm^-1)	1100	600
Transition temperature (°C)	1175	260
Specific heat (J/(g⋅K))	0.179	0.151
Thermal conductivity, W/(m·K)	1.38	0.628
Expansion coefficient (10^-6/K)	0.55	17.2
Density (g/cm^3)	2.20	4.33
Knoop hardness (kg/mm^2)	600	225
Fracture toughness (MPam^1/2)	0.72	0.32
Poisson’s ratio	0.17	0.17
Young’s modulus (Gpa)	70	58.3
Shear’s modulus (Gpa)	31.2	20.5
Bulk’s modulus (Gpa)	36.7	47.7
Refractive index (@ 0.589 um)	1.458	1.499
Abbe number	68	76
Zero material dispersion wavelength (𝜇m)	1.3	1.6
Nonlinear index (10^-13 esu)	1	0.85
Thermo-optic coefficient (10^-6/K)	11.9	−14.75