K-LaK18 by Sumita
Standard
Medium
Environmentally Friendly
K-LaK18 by Sumita is a standard optical glass with a medium melt frequency. It transmits from 0.29 to 2.00 µm with an nd of 1.72916 and a Vd of 54.7. It has low thermal expansion (CTE of 5.6×10⁻⁶/K) and average chemical resistance.
Refractive Index vs Wavelength
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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) | 5.6 |
|---|---|
| TCE 100/300°C (10-6/K) | 7.1 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[6.73 \times 10^{-7} + 2(2.1 \times 10^{-8})\,\Delta T + 3(-1.63 \times 10^{-10})\,\Delta T^2 + \frac{4.91 \times 10^{-7} + 2(2.14 \times 10^{-10})\,\Delta T}{\lambda - 0.164}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 4 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| 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 |