LAFK55 by Sumita

Obsolete Very Rare Environmentally Dangerous

LAFK55 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.28 to 2.00 µm with an nd of 1.694 and a Vd of 56.3. 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: 0.280–2.000 µm
Optical Properties
Refractive Index (nd) 1.694
Abbe Number (Vd) 56.3
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.81782 - 0.0128923\,\lambda^2 + 0.0185173\,\lambda^{-2} + 0.000310526\,\lambda^{-4} - 1.44814 \times 10^{-6}\,\lambda^{-6} + 5.76494 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) —
TCE 100/300°C (10-6/K) 9.5
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) 4.38
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 4
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LAK31 Schott 1.696732 56.420174
H-LAK12 CDGM 1.6968 56.175305
C97-56 Corning 1.697 56.222926
LAC15 Hoya 1.6968 56.114704
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
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-LaFK55 Sumita 1.694 56.3
LAK14 Sumita 1.6968 55.6
K-LaK14 Sumita 1.6968 55.6
K-LaFK55(M) Sumita 1.68875 55.8
LAK9 Sumita 1.691 54.8
K-LaK9 Sumita 1.691 54.8
K-LaFK58(M) Sumita 1.69097 58.4
LAK12 Sumita 1.6779 55.5
K-LaK12 Sumita 1.6779 55.5
K-LaFK58 Sumita 1.6956 59.0
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