K-SFLDn3 by Sumita

Standard Rare Environmentally Friendly

K-SFLDn3 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.35 to 2.00 µm with an nd of 1.8467 and a Vd of 23.8. It has medium thermal expansion (CTE of 8.6×10⁻⁶/K) and excellent chemical resistance.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.4–1.55 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.4–1.55 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.350–2.000 µm
Optical Properties
Refractive Index (nd) 1.8467
Abbe Number (Vd) 23.8
Dispersion Formula Schott
Wavelength Range 0.4 — 1.55 µm
$$n(\lambda) = \sqrt{3.25145 - 0.0135184\,\lambda^2 + 0.0481641\,\lambda^{-2} + 0.00307709\,\lambda^{-4} - 0.000165014\,\lambda^{-6} + 3.11608 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.6
TCE 100/300°C (10-6/K) 10.6
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-5.35 \times 10^{-6} + 2(1.43 \times 10^{-8})\,\Delta T + 3(-2.48 \times 10^{-10})\,\Delta T^2 + \frac{1.02 \times 10^{-6} + 2(9.91 \times 10^{-10})\,\Delta T}{\lambda - 0.296}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.49
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
H-ZF52A CDGM 1.84667 23.791236
H-ZF52 CDGM 1.84666 23.784497
H-ZF52GT CDGM 1.84666 23.784497
H-ZF52TT CDGM 1.84666 23.784497
TIH53 Ohara 1.846659 23.780116
FDS90 Hoya 1.84666 23.78
N-SF57HT Schott 1.84666 23.78
FDS90-SG Hoya 1.84666 23.78
N-SF57HTultra Schott 1.84666 23.78
N-SF57 Schott 1.84666 23.78
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-SFLDn3W Sumita 1.8467 23.8
SFLDN3 Sumita 1.84666 23.9
SFN3 Sumita 1.84666 23.9
K-PSFn3 Sumita 1.83917 23.9
K-PSFn4 Sumita 1.844 24.8
K-PSFn4(M) Sumita 1.83932 24.8
K-PSFn3(M) Sumita 1.83352 24.0
K-PSFn185 Sumita 1.8507 26.9
K-PSFn185(M) Sumita 1.84524 27.1
SFLD20 Sumita 1.81786 23.7
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