K-LaFK50 by Sumita

Preferred Common Precision Molding Environmentally Friendly
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36–1.55 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36–1.55 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.280–2.000 µm
Optical Properties
Refractive Index (nd) 1.772
Abbe Number (Vd) 50.0
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{3.07013 - 0.0120375\,\lambda^2 + 0.0239789\,\lambda^{-2} + 0.000561532\,\lambda^{-4} - 1.05299 \times 10^{-5}\,\lambda^{-6} + 1.17109 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.3
TCE 100/300°C (10-6/K) 9.0
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-3.11 \times 10^{-7} + 2(1.35 \times 10^{-8})\,\Delta T + 3(-2.34 \times 10^{-10})\,\Delta T^2 + \frac{5.76 \times 10^{-7} + 2(8.89 \times 10^{-10})\,\Delta T}{\lambda - 0.201}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 5.2
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 1
Stain Resistance
Acid Resistance 3
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
TAF1 Hoya 1.7725 49.63
N-LAF34 Schott 1.7725 49.62
LAH66 Ohara 1.772499 49.60134
H-LAF50B CDGM 1.7725 49.598996
S-LAH66 Ohara 1.772499 49.598371
LAFN28 Schott 1.773142 49.568242
D-LAF50 CDGM 1.774 49.590362
D-LAF50-25 CDGM 1.77288 49.519338
M-TAF105 Hoya 1.7725 49.5
MP-TAF105 Hoya 1.7725 49.5
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
LASFN7 Sumita 1.7725 49.6
K-LaSFn7 Sumita 1.7725 49.6
K-LaFK50L Sumita 1.7682 50.0
LASKN3 Sumita 1.774 50.5
K-LaFK50(M) Sumita 1.76831 49.7
K-LaFK50T Sumita 1.766 49.8
K-LaFK50T(M) Sumita 1.76209 49.6
LAFN8 Sumita 1.756 47.6
K-LaSKn1 Sumita 1.755 52.4
LASKN1 Sumita 1.755 52.4
Compare Glasses