K-LaK14 by Sumita

Standard Rare Environmentally Friendly

K-LaK14 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 1.6968 and a Vd of 55.6. It has low thermal expansion (CTE of 6.4×10⁻⁶/K) and average 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) 1.6968
Abbe Number (Vd) 55.6
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.82772 - 0.0138385\,\lambda^2 + 0.0179847\,\lambda^{-2} + 0.000577779\,\lambda^{-4} - 3.77128 \times 10^{-5}\,\lambda^{-6} + 2.29359 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.4
TCE 100/300°C (10-6/K) 8.1
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-4.5 \times 10^{-7} + 2(1.44 \times 10^{-8})\,\Delta T + 3(-3.03 \times 10^{-10})\,\Delta T^2 + \frac{5.54 \times 10^{-7} + 2(7.23 \times 10^{-10})\,\Delta T}{\lambda - 0.135}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.64
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 Compare
S-LAL14 Ohara 1.696797 55.532241
LAL14 Ohara 1.696796 55.528037
H-LAK51A CDGM 1.6968 55.526357
LAC14 Hoya 1.6968 55.46
M-LAC14 Hoya 1.6968 55.46
MP-LAC14-80 Hoya 1.6976 55.51
LAKN14 Schott 1.6968 55.410215
N-LAK14 Schott 1.6968 55.41
C97-55 Corning 1.697005 55.409848
LAC15 Hoya 1.6968 56.114704
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LAK14 Sumita 1.6968 55.6
LAFK55 Sumita 1.694 56.3
K-LaFK55 Sumita 1.694 56.3
K-LaFK55(M) Sumita 1.68875 55.8
K-LaK9 Sumita 1.691 54.8
LAK9 Sumita 1.691 54.8
LAK13 Sumita 1.6935 53.4
K-VC80 Sumita 1.69384 53.1
K-LaK12 Sumita 1.6779 55.5
LAK12 Sumita 1.6779 55.5
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