FD8 by Hoya
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) | 1.688931 |
|---|---|
| Abbe Number (Vd) | 31.158857 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.25 — 1.55 µm |
$$n(\lambda) = \sqrt{2.75778 - 0.00861604\,\lambda^2 + 0.0305392\,\lambda^{-2} + 0.00104929\,\lambda^{-4} - 1.17465 \times 10^{-6}\,\lambda^{-6} + 6.31118 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | 7.7 |
|---|---|
| TCE 100/300°C (10-6/K) | 82.0 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[7.42823 \times 10^{-6} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
| Density (g/cm³) | 4.21 |
|---|---|
| Relative Cost | — |
Mechanical Properties
| Young's Modulus (GPa) | — |
|---|---|
| Poisson's Ratio | — |
| Knoop Hardness (kgf/mm²) | — |
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | 1 |
| Acid Resistance | 2 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| H-ZF10 | CDGM | 1.68893 | 31.16057 | |
| SF8 | Schott | 1.688932 | 31.176063 | |
| ZF10 | CDGM | 1.688934 | 31.184753 | |
| SF8 | Sumita | 1.68893 | 31.2 | |
| K-SFLD8W | Sumita | 1.6891 | 31.2 | |
| C89-31 | Corning | 1.689004 | 31.210861 | |
| K-SFLD8 | Sumita | 1.68893 | 31.1 | |
| PBM28W | Ohara | 1.68893 | 31.082901 | |
| PBM28 | Ohara | 1.68893 | 31.082901 | |
| D-ZF10 | CDGM | 1.68893 | 31.077677 |