LAFN28 by Schott

Obsolete Unknown Environmentally Dangerous

LAFN28 by Schott is an obsolete optical glass. It transmits from 0.33 to 2.33 µm with an nd of 1.773142 and a Vd of 49.568242. It has low thermal expansion (CTE of 5.8×10⁻⁶/K), below average chemical resistance, high relative cost, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.334–2.325 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.334–2.325 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.334–2.325 µm
Optical Properties
Refractive Index (nd) 1.773142
Abbe Number (Vd) 49.568242
Dispersion Formula Sellmeier
Wavelength Range 0.334 — 2.325 µm
$$n(\lambda) = \sqrt{1 + \frac{1.75883\,\lambda^2}{\lambda^2 - 0.0087281} + \frac{0.315198\,\lambda^2}{\lambda^2 - 0.0293021} + \frac{1.1903\,\lambda^2}{\lambda^2 - 85.1781}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 5.8
TCE 100/300°C (10-6/K) 7.0
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[3.89 \times 10^{-6} + 2(1.02 \times 10^{-8})\,\Delta T + 3(-1.91 \times 10^{-11})\,\Delta T^2 + \frac{5.88 \times 10^{-7} + 2(7.57 \times 10^{-10})\,\Delta T}{\lambda - 0.181}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.24
Relative Cost 18.75
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance 1
Acid Resistance 51
Alkali Resistance 1
Phosphate Resistance 1
Notes

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Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
D-LAF50-25 CDGM 1.77288 49.519338
S-LAH66 Ohara 1.772499 49.598371
H-LAF50B CDGM 1.7725 49.598996
K-LaSFn7 Sumita 1.7725 49.6
LASFN7 Sumita 1.7725 49.6
LAH66 Ohara 1.772499 49.60134
TAF1 Hoya 1.7725 49.63
M-TAF105 Hoya 1.7725 49.5
MP-TAF105 Hoya 1.7725 49.5
MC-TAF105 Hoya 1.7725 49.5
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
N-LAF34 Schott 1.7725 49.62
LAFN24 Schott 1.757191 47.81177
N-LAF21 Schott 1.788 47.49
LAFN21 Schott 1.788309 47.470398
N-LAK33B Schott 1.755 52.3
N-LAK33A Schott 1.75393 52.27
LAK33 Schott 1.753977 52.430467
N-LAK33 Schott 1.753977 52.430467
N-LAF35 Schott 1.7433 49.4
N-LAK28 Schott 1.74429 50.77
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