K-LaSFn9 by Sumita

Standard Rare Environmentally Friendly

K-LaSFn9 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.31 to 2.00 µm with an nd of 1.816 and a Vd of 46.7. It has low thermal expansion (CTE of 6.3×10⁻⁶/K) and good chemical resistance.

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: 0.310–2.000 µm
Optical Properties
Refractive Index (nd) 1.816
Abbe Number (Vd) 46.7
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{3.21844 - 0.0149064\,\lambda^2 + 0.0269262\,\lambda^{-2} + 0.000874097\,\lambda^{-4} - 4.03313 \times 10^{-5}\,\lambda^{-6} + 3.16777 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.3
TCE 100/300°C (10-6/K) 7.6
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.34 \times 10^{-6} + 2(2.13 \times 10^{-8})\,\Delta T + 3(-1.52 \times 10^{-10})\,\Delta T^2 + \frac{5.8 \times 10^{-7} + 2(6.95 \times 10^{-10})\,\Delta T}{\lambda - 0.204}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.96
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 Compare
LAH59 Ohara 1.816 46.626446
S-LAH59 Ohara 1.816 46.620561
TAF5 Hoya 1.816 46.57
H-ZLAF69A CDGM 1.816 46.556066
H-ZLAF69 CDGM 1.816 46.5493
TAF3 Hoya 1.8042 46.5
N-LASF44 Schott 1.8042 46.5
TAF3D Hoya 1.8042 46.5
S-LAH65V Ohara 1.803999 46.583432
LAH65 Ohara 1.804 46.575911
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LASFN9 Sumita 1.816 46.7
K-LaSFn6 Sumita 1.804 46.6
LASFN6 Sumita 1.80235 46.7
LASFN10 Sumita 1.8155 44.4
K-LaSFn10 Sumita 1.8155 44.4
LASFN19 Sumita 1.795 45.2
K-VC100 Sumita 1.804 43.6
LASFN16 Sumita 1.7883 47.4
K-LaSFn16 Sumita 1.7883 47.4
K-VC100(M) Sumita 1.79916 43.5
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