K-LaK7 by Sumita
Standard
Rare
Environmentally Friendly
K-LaK7 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.29 to 2.00 µm with an nd of 1.6516 and a Vd of 58.3. It has medium thermal expansion (CTE of 6.8×10⁻⁶/K) and below average chemical resistance.
Refractive Index vs Wavelength
Refractive Index Calculator
dn/dλ vs Wavelength
dn/dλ Calculator
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Optical Properties
Thermal Properties
| TCE -30/70°C (10-6/K) | 6.8 |
|---|---|
| TCE 100/300°C (10-6/K) | 8.4 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.13 \times 10^{-6} + 2(1.62 \times 10^{-8})\,\Delta T + 3(-5.04 \times 10^{-11})\,\Delta T^2 + \frac{3.71 \times 10^{-7} + 2(6.15 \times 10^{-10})\,\Delta T}{\lambda - 0.214}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Chemical Resistance
| Climatic Resistance | 2 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 5 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| 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 |