SF18 by Schott
Obsolete
Unknown
Environmentally Dangerous
Refractive Index vs Wavelength
Refractive Index Calculator
dn/dλ vs Wavelength
dn/dλ Calculator
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Optical Properties
| Refractive Index (nd) | 1.72151 |
|---|---|
| Abbe Number (Vd) | 29.245495 |
| Dispersion Formula | Sellmeier |
| Wavelength Range | 0.334 — 2.325 µm |
$$n(\lambda) = \sqrt{1 + \frac{1.56441\,\lambda^2}{\lambda^2 - 0.0121864} + \frac{0.291414\,\lambda^2}{\lambda^2 - 0.0535568} + \frac{0.960308\,\lambda^2}{\lambda^2 - 111.451}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | 8.1 |
|---|---|
| TCE 100/300°C (10-6/K) | 9.0 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[4.66 \times 10^{-6} + 2(1.71 \times 10^{-8})\,\Delta T + 3(-4.9 \times 10^{-11})\,\Delta T^2 + \frac{1.41 \times 10^{-6} + 2(1.31 \times 10^{-9})\,\Delta T}{\lambda - 0.26}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
| Density (g/cm³) | 4.49 |
|---|---|
| Relative Cost | 2.25 |
Mechanical Properties
| Young's Modulus (GPa) | — |
|---|---|
| Poisson's Ratio | — |
| Knoop Hardness (kgf/mm²) | — |
Chemical Resistance
| Climatic Resistance | 2 |
|---|---|
| Stain Resistance | 1 |
| Acid Resistance | 3 |
| Alkali Resistance | 2 |
| Phosphate Resistance | 3 |
Notes
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Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| FD18 | Hoya | 1.721507 | 29.243436 | |
| PBH18 | Ohara | 1.721506 | 29.243262 | |
| S-TIH18 | Ohara | 1.721507 | 29.23233 | |
| SF18 | Sumita | 1.72151 | 29.3 | |
| CD120 | Sumita | 1.7225 | 29.2 | |
| K-CD120 | Sumita | 1.7225 | 29.2 | |
| FD20 | Hoya | 1.720225 | 29.300359 | |
| SFN1 | Sumita | 1.72022 | 29.3 | |
| D17-29 | Corning | 1.717409 | 29.492751 | |
| H-ZF3 | CDGM | 1.71736 | 29.49911 |