FD20 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
No transmission data available.
Optical Properties
| Refractive Index (nd) | 1.720225 |
|---|---|
| Abbe Number (Vd) | 29.300359 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.334 — 2.325 µm |
$$n(\lambda) = \sqrt{2.84804 - 0.00701304\,\lambda^2 + 0.0372191\,\lambda^{-2} + 0.000297448\,\lambda^{-4} + 0.000127677\,\lambda^{-6} + 2.01434 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | — |
|---|---|
| TCE 100/300°C (10-6/K) | — |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right]
\Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
Physical Properties
| Density (g/cm³) | — |
|---|---|
| Relative Cost | — |
Mechanical Properties
| Young's Modulus (GPa) | — |
|---|---|
| Poisson's Ratio | — |
| Knoop Hardness (kgf/mm²) | — |
Chemical Resistance
| Climatic Resistance | — |
|---|---|
| Stain Resistance | — |
| Acid Resistance | — |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| SFN1 | Sumita | 1.72022 | 29.3 | |
| SF18 | Sumita | 1.72151 | 29.3 | |
| SF18 | Schott | 1.72151 | 29.245495 | |
| PBH18 | Ohara | 1.721506 | 29.243262 | |
| S-TIH18 | Ohara | 1.721507 | 29.23233 | |
| P-SF69 | Schott | 1.7225 | 29.23 | |
| K-CD120 | Sumita | 1.7225 | 29.2 | |
| CD120 | Sumita | 1.7225 | 29.2 | |
| D17-29 | Corning | 1.717409 | 29.492751 | |
| H-ZF3 | CDGM | 1.71736 | 29.49911 |