FF8 by Hoya
Preferred
Very Common
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) | 1.75211 |
|---|---|
| Abbe Number (Vd) | 25.05 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.36501 — 1.5296 µm |
$$n(\lambda) = \sqrt{2.95644 - 0.0197622\,\lambda^2 + 0.0298788\,\lambda^{-2} + 0.00518309\,\lambda^{-4} - 0.000542024\,\lambda^{-6} + 4.84632 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | 6.1 |
|---|---|
| TCE 100/300°C (10-6/K) | 7.0 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-3.67 \times 10^{-6} + 2(1.1 \times 10^{-8})\,\Delta T + 3(-3.23 \times 10^{-11})\,\Delta T^2 + \frac{7.57 \times 10^{-7} + 2(9.89 \times 10^{-10})\,\Delta T}{\lambda - 0.306}\right]
\Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
| Density (g/cm³) | 3.14 |
|---|---|
| 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 | 1 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Notes
Recommended glass type
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| TPH55 | Ohara | 1.755502 | 25.066156 | |
| SF14 | Sumita | 1.76182 | 26.5 | |
| K-SFLD14 | Sumita | 1.76182 | 26.5 | |
| S-TIH14 | Ohara | 1.761821 | 26.517885 | |
| TIH14 | Ohara | 1.761821 | 26.517966 | |
| N-SF14 | Schott | 1.76182 | 26.53 | |
| SF14 | Schott | 1.76182 | 26.53 | |
| PBH14 | Ohara | 1.761819 | 26.553651 | |
| PBH14W | Ohara | 1.761819 | 26.553651 | |
| ZF12 | CDGM | 1.761822 | 26.555686 |