LAKN7 by Sumita

Obsolete Very Rare Environmentally Dangerous

LAKN7 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.34 to 2.00 µm with an nd of 1.67 and a Vd of 51.7. It has average chemical resistance and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.27–2.0 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.27–2.0 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 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.73349 - 0.0102973\,\lambda^2 + 0.0194489\,\lambda^{-2} + 0.000291966\,\lambda^{-4} + 4.46498 \times 10^{-6}\,\lambda^{-6} + 8.57856 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) —
TCE 100/300°C (10-6/K) 8.5
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
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 Compare
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
S-BSM25 Ohara 1.658441 50.877554
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-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
K-BaFn3 Sumita 1.66422 49.2
BAFN3 Sumita 1.66422 49.2
K-VC80(M) Sumita 1.68983 52.9
LAKN10 Sumita 1.692 50.6
Compare Glasses
    Compare Selected