LAK18 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) | 1.72916 |
|---|---|
| Abbe Number (Vd) | 54.7 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.27 — 2.0 µm |
$$n(\lambda) = \sqrt{2.93265 - 0.014636\,\lambda^2 + 0.0207833\,\lambda^{-2} + 0.000221712\,\lambda^{-4} + 1.54042 \times 10^{-5}\,\lambda^{-6} - 3.06689 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | — |
|---|---|
| TCE 100/300°C (10-6/K) | 7.1 |
| 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) | 4.08 |
|---|---|
| Relative Cost | — |
Mechanical Properties
| Young's Modulus (GPa) | — |
|---|---|
| Poisson's Ratio | — |
| Knoop Hardness (kgf/mm²) | — |
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 4 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | |
|---|---|---|---|---|
| H-LAK52 | CDGM | 1.72916 | 54.684737 | |
| LAL18 | Ohara | 1.729157 | 54.683134 | |
| S-LAL18 | Ohara | 1.729157 | 54.680013 | |
| TAC8 | Hoya | 1.72916 | 54.67 | |
| TAC8P | Hoya | 1.72916 | 54.54 | |
| N-LAK34 | Schott | 1.72916 | 54.5 | |
| S-LAL19 | Ohara | 1.72916 | 54.095223 | |
| MP-TAC80-60 | Hoya | 1.72963 | 54.07 | |
| M-TAC80 | Hoya | 1.72903 | 54.04 | |
| D-LAK52 | CDGM | 1.7305 | 53.944268 |