K-LaFn5 by Sumita

Standard Rare Environmentally Friendly

K-LaFn5 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.33 to 2.00 µm with an nd of 1.743 and a Vd of 49.2. It has low thermal expansion (CTE of 5.1×10⁻⁶/K) and 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: 0.330–2.000 µm
Optical Properties
Refractive Index (nd) 1.743
Abbe Number (Vd) 49.2
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.97466 - 0.0154904\,\lambda^2 + 0.0216764\,\lambda^{-2} + 0.000790795\,\lambda^{-4} - 3.50692 \times 10^{-5}\,\lambda^{-6} + 2.12354 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 5.1
TCE 100/300°C (10-6/K) 7.1
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[2.26 \times 10^{-6} + 2(2.18 \times 10^{-8})\,\Delta T + 3(-2.34 \times 10^{-10})\,\Delta T^2 + \frac{5.21 \times 10^{-7} + 2(6.65 \times 10^{-10})\,\Delta T}{\lambda - 0.203}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.05
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
NBF1 Hoya 1.7433 49.22
H-LAF53 CDGM 1.7433 49.221808
L-LAM60 Ohara 1.743198 49.295578
LAM60 Ohara 1.743198 49.309053
D-LAF53-25 CDGM 1.7421 49.246024
D-LAF53 CDGM 1.7433 49.325949
M-NBF1 Hoya 1.7433 49.33
MC-NBF1 Hoya 1.7433 49.33
MP-NBF1 Hoya 1.7433 49.33
S-LAM60 Ohara 1.743198 49.339444
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LAFN5 Sumita 1.743 49.2
LAFN7 Sumita 1.735 49.5
LAKN12 Sumita 1.7335 51.2
LAFN8 Sumita 1.756 47.6
K-LaFK50T(M) Sumita 1.76209 49.6
K-LaFK50T Sumita 1.766 49.8
K-LaK10 Sumita 1.72 50.3
LAK10 Sumita 1.72 50.3
K-LaFK50(M) Sumita 1.76831 49.7
K-LaKn14 Sumita 1.741 52.7
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