LAKL12 by Schott

Obsolete Unknown Environmentally Dangerous

LAKL12 by Schott is an obsolete optical glass. It transmits from 0.32 to 2.50 µm with an nd of 1.6779 and a Vd of 54.92. It has medium thermal expansion (CTE of 6.8×10⁻⁶/K), below average chemical resistance, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.32–2.5 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.32–2.5 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.320–2.500 µm
Optical Properties
Refractive Index (nd) 1.6779
Abbe Number (Vd) 54.92
Dispersion Formula Sellmeier
Wavelength Range 0.32 — 2.5 µm
$$n(\lambda) = \sqrt{1 + \frac{1.28115\,\lambda^2}{\lambda^2 - 0.0063644} + \frac{0.482608\,\lambda^2}{\lambda^2 - 0.0213764} + \frac{1.16554\,\lambda^2}{\lambda^2 - 93.2772}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.8
TCE 100/300°C (10-6/K) 8.0
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[2.26 \times 10^{-6} + 2(1.05 \times 10^{-8})\,\Delta T + 3(-8.4 \times 10^{-12})\,\Delta T^2 + \frac{4.57 \times 10^{-7} + 2(5.86 \times 10^{-10})\,\Delta T}{\lambda - 0.21}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.32
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 3
Stain Resistance 3
Acid Resistance 53
Alkali Resistance 2
Phosphate Resistance 3
Notes

old, was replaced by N-LAK12

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
D-LAK5 CDGM 1.6779 54.889665
L-LAL12 Ohara 1.6779 54.88744
D-LAK5-25 CDGM 1.67686 54.805426
LAL12 Ohara 1.6779 55.337587
S-LAL12 Ohara 1.6779 55.341195
S-LAL12Q Ohara 1.6779 55.346888
K-LaK12 Sumita 1.6779 55.5
LAK12 Sumita 1.6779 55.5
H-LAK5A CDGM 1.6779 55.51497
C78-56 Corning 1.678004 55.519168
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
LAKN12 Schott 1.6779 55.199566
N-LAK12 Schott 1.6779 55.2
LAK9G15 Schott 1.69064 54.76
N-LAK9 Schott 1.691 54.71
LAK9 Schott 1.691002 54.708408
N-LAK14 Schott 1.6968 55.41
LAKN14 Schott 1.6968 55.410215
LAKN13 Schott 1.693501 53.330054
P-LAK35 Schott 1.6935 53.2
LAK23 Schott 1.668816 57.38444
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