LLF7 by Sumita
Obsolete
Very Rare
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) | 1.54869 |
|---|---|
| Abbe Number (Vd) | 45.4 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.27 — 2.0 µm |
$$n(\lambda) = \sqrt{2.35132 - 0.00823454\,\lambda^2 + 0.0161847\,\lambda^{-2} + 0.000338946\,\lambda^{-4} + 7.33135 \times 10^{-6}\,\lambda^{-6} + 8.69223 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | — |
|---|---|
| TCE 100/300°C (10-6/K) | 9.5 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
| Density (g/cm³) | 2.97 |
|---|---|
| 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 | |
|---|---|---|---|---|
| LLF7 | Schott | 1.548831 | 45.40834 | |
| FEL7 | Hoya | 1.54883 | 45.439785 | |
| PBL7 | Ohara | 1.548689 | 45.555746 | |
| B48-46 | Corning | 1.548098 | 45.718533 | |
| PBL1Y | Ohara | 1.548141 | 45.733282 | |
| LLF1 | Schott | 1.54814 | 45.75 | |
| PBL1 | Ohara | 1.548141 | 45.781144 | |
| S-TIL1 | Ohara | 1.548141 | 45.784277 | |
| E-FEL1 | Hoya | 1.54814 | 45.82 | |
| H-QF1 | CDGM | 1.54814 | 45.820011 |