K-LaKn4 by Sumita

Obsolete Very Rare Environmentally Friendly

K-LaKn4 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.31 to 2.00 µm with an nd of 1.671 and a Vd of 57.2. It has below 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) 1.671
Abbe Number (Vd) 57.2
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.74496 - 0.0130267\,\lambda^2 + 0.0166615\,\lambda^{-2} + 0.00048278\,\lambda^{-4} - 2.58158 \times 10^{-5}\,\lambda^{-6} + 1.52412 \times 10^{-6}\,\lambda^{-8}}$$
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) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-1.88 \times 10^{-6} + 2(1.19 \times 10^{-8})\,\Delta T + 3(-1.1 \times 10^{-10})\,\Delta T^2 + \frac{3.48 \times 10^{-7} + 2(6.14 \times 10^{-10})\,\Delta T}{\lambda - 0.223}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.88
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 2
Stain Resistance —
Acid Resistance 5
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LACL7 Hoya 1.669996 57.308358
LAL52 Ohara 1.669999 57.327972
S-LAL52 Ohara 1.669999 57.327972
LAK23 Schott 1.668816 57.38444
H-LAK1 CDGM 1.6595 57.34726
LAK11 Schott 1.658302 57.261599
LAC11 Hoya 1.658296 57.262085
S-LAL11 Ohara 1.658296 57.332589
LAL11 Ohara 1.658296 57.332589
D-LAK70 CDGM 1.6691 55.389689
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LAKN4 Sumita 1.671 57.2
K-LaK11 Sumita 1.6583 57.3
LAK11 Sumita 1.6583 57.3
K-VC78 Sumita 1.66955 55.4
VC78 Sumita 1.6691 55.4
LAK12 Sumita 1.6779 55.5
K-LaK12 Sumita 1.6779 55.5
K-VC78(M) Sumita 1.66624 55.1
K-LaFK55(M) Sumita 1.68875 55.8
LAK7 Sumita 1.6516 58.3
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