K-LaSFn17 by Sumita

Standard Medium Environmentally Friendly

K-LaSFn17 by Sumita is a standard optical glass with a medium melt frequency. It transmits from 0.30 to 2.00 µm with an nd of 1.883 and a Vd of 40.8. It has low thermal expansion (CTE of 6.3×10⁻⁶/K) and excellent chemical resistance.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.4–1.55 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.4–1.55 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.300–2.000 µm
Optical Properties
Refractive Index (nd) 1.883
Abbe Number (Vd) 40.8
Dispersion Formula Schott
Wavelength Range 0.4 — 1.55 µm
$$n(\lambda) = \sqrt{3.44341 - 0.0154747\,\lambda^2 + 0.033696\,\lambda^{-2} + 0.00128786\,\lambda^{-4} - 4.54742 \times 10^{-5}\,\lambda^{-6} + 3.86796 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.3
TCE 100/300°C (10-6/K) 7.9
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.16 \times 10^{-6} + 2(1.35 \times 10^{-8})\,\Delta T + 3(-2.1 \times 10^{-10})\,\Delta T^2 + \frac{7.19 \times 10^{-7} + 2(4.1 \times 10^{-10})\,\Delta T}{\lambda - 0.207}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 5.54
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
H-ZLAF68B CDGM 1.883004 40.806875
TAFD30 Hoya 1.883 40.81
LAH58 Ohara 1.882997 40.778667
S-LAH58 Ohara 1.882997 40.765107
N-LASF31A Schott 1.883 40.76
H-ZLAF68C CDGM 1.883 40.847465
LASFN31 Schott 1.880669 41.009774
N-LASF31 Schott 1.88067 41.01
H-ZLAF73 CDGM 1.881 40.161331
TAFD33 Hoya 1.881 40.14
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LASFN17 Sumita 1.883 40.9
LASFN13 Sumita 1.863 41.6
K-VC185 Sumita 1.85375 40.6
K-VC99 Sumita 1.8506 41.6
K-VC90 Sumita 1.8528 39.0
K-VC185(M) Sumita 1.84909 40.5
K-VC90(M) Sumita 1.84859 38.9
K-VC99(M) Sumita 1.84604 41.5
K-VC91 Sumita 1.8866 35.0
K-VC91(M) Sumita 1.88175 34.9
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