LAK7 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) | 1.6516 |
|---|---|
| Abbe Number (Vd) | 58.3 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.27 — 2.0 µm |
$$n(\lambda) = \sqrt{2.68059 - 0.0105139\,\lambda^2 + 0.0171402\,\lambda^{-2} + 8.58111 \times 10^{-5}\,\lambda^{-4} + 2.13483 \times 10^{-5}\,\lambda^{-6} - 7.4092 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | — |
|---|---|
| TCE 100/300°C (10-6/K) | 8.4 |
| 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) | 3.76 |
|---|---|
| Relative Cost | — |
Mechanical Properties
| Young's Modulus (GPa) | — |
|---|---|
| Poisson's Ratio | — |
| Knoop Hardness (kgf/mm²) | — |
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 5 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| LAC7 | Hoya | 1.6516 | 58.4 | |
| H-LAK50A | CDGM | 1.6516 | 58.403057 | |
| C52-58 | Corning | 1.6516 | 58.511488 | |
| LAKN7 | Schott | 1.6516 | 58.517773 | |
| LAL7 | Ohara | 1.651597 | 58.519433 | |
| N-LAK7 | Schott | 1.6516 | 58.52 | |
| S-LAL7Q | Ohara | 1.6516 | 58.544459 | |
| S-LAL7 | Ohara | 1.651597 | 58.550655 | |
| BSM36 | Ohara | 1.642495 | 58.369399 | |
| S-BSM36 | Ohara | 1.642495 | 58.369399 |