N-LAK9 by Schott

Preferred Unknown Environmentally Friendly

N-LAK9 by Schott is a preferred optical glass. It transmits from 0.32 to 2.50 µm with an nd of 1.691 and a Vd of 54.71. It has low thermal expansion (CTE of 6.3×10⁻⁶/K), below average chemical resistance, and moderate relative cost.

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) 1.691
Abbe Number (Vd) 54.71
Dispersion Formula Sellmeier
Wavelength Range 0.32 — 2.5 µm
$$n(\lambda) = \sqrt{1 + \frac{1.46232\,\lambda^2}{\lambda^2 - 0.0072427} + \frac{0.3444\,\lambda^2}{\lambda^2 - 0.0243353} + \frac{1.15508\,\lambda^2}{\lambda^2 - 85.4687}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.3
TCE 100/300°C (10-6/K) 7.5
Thermal Conductivity (W/mK) 0.91
Heat Capacity (J/gK) 0.649
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[2.11 \times 10^{-6} + 2(1.11 \times 10^{-8})\,\Delta T + 3(1.82 \times 10^{-12})\,\Delta T^2 + \frac{4.74 \times 10^{-7} + 2(-3.47 \times 10^{-10})\,\Delta T}{\lambda - 0.146}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.51
Relative Cost 3.3
Mechanical Properties
Young's Modulus (GPa) 110.0
Poisson's Ratio 0.29
Knoop Hardness (kgf/mm²) 700.0
Chemical Resistance
Climatic Resistance 3
Stain Resistance 3
Acid Resistance 52
Alkali Resistance 1
Phosphate Resistance 4
Notes

step 0.5 available

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LAC9 Hoya 1.691 54.7
C90-55 Corning 1.691008 54.793839
K-LaK9 Sumita 1.691 54.8
LAK9 Sumita 1.691 54.8
H-LAK59A CDGM 1.691 54.815309
S-LAL9 Ohara 1.691002 54.822578
LAL9 Ohara 1.691002 54.84322
H-LAK2A CDGM 1.69211 54.539198
C97-55 Corning 1.697005 55.409848
LAC14 Hoya 1.6968 55.46
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
LAK9 Schott 1.691002 54.708408
LAK9G15 Schott 1.69064 54.76
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
LAKL12 Schott 1.6779 54.92
LAKN12 Schott 1.6779 55.199566
N-LAK12 Schott 1.6779 55.2
LAK31 Schott 1.696732 56.420174
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