K-LaKn7 by Sumita

Standard Rare 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: 0.340–2.000 µm
Optical Properties
Refractive Index (nd) 1.67
Abbe Number (Vd) 51.7
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.73574 - 0.0114767\,\lambda^2 + 0.017975\,\lambda^{-2} + 0.000720203\,\lambda^{-4} - 5.1934 \times 10^{-5}\,\lambda^{-6} + 3.59801 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.3
TCE 100/300°C (10-6/K) 8.5
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.14 \times 10^{-7} + 2(1.48 \times 10^{-8})\,\Delta T + 3(-1.61 \times 10^{-10})\,\Delta T^2 + \frac{5.55 \times 10^{-7} + 2(4.75 \times 10^{-10})\,\Delta T}{\lambda - 0.191}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.78
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 1
Stain Resistance
Acid Resistance 5
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
H-LAK67 CDGM 1.67 51.738482
LACL4 Hoya 1.669603 51.65903
BBO Generic Birefringent 1.670737 52.593907
LAL56 Ohara 1.677898 50.723364
S-LAL56 Ohara 1.677898 50.722184
LACL9 Hoya 1.6779 50.551353
C58-51 Corning 1.658503 51.012014
SSKN5 Schott 1.65844 50.882921
N-SSK5 Schott 1.65844 50.88
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Similar Glasses (Sumita)
Glass Manufacturer nd Vd
LAKN7 Sumita 1.67 51.7
LAKN8 Sumita 1.678 50.7
SSK5 Sumita 1.65844 50.8
LAKN9 Sumita 1.678 53.3
LAKN11 Sumita 1.6583 53.4
K-LaKn11 Sumita 1.6583 53.4
BAFN3 Sumita 1.66422 49.2
K-BaFn3 Sumita 1.66422 49.2
K-VC80(M) Sumita 1.68983 52.9
LAKN10 Sumita 1.692 50.6
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