K-VC78 by Sumita
Standard
Medium
Precision Molding
Environmentally Friendly
K-VC78 by Sumita is a standard optical glass with a medium melt frequency. It transmits from 0.27 to 2.00 µm with an nd of 1.66955 and a Vd of 55.4. It has medium thermal expansion (CTE of 8.0×10⁻⁶/K), average chemical resistance, and precision molding compatibility.
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) | 8.0 |
|---|---|
| TCE 100/300°C (10-6/K) | 10.0 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-1 \times 10^{-6} + 2(1.6 \times 10^{-8})\,\Delta T + 3(-1.38 \times 10^{-10})\,\Delta T^2 + \frac{5.07 \times 10^{-7} + 2(3.13 \times 10^{-10})\,\Delta T}{\lambda - 0.19}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 4 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| D-LAK70 | CDGM | 1.6691 | 55.389689 | |
| D-LAK70-25 | CDGM | 1.668 | 55.295752 | |
| H-LAK11 | CDGM | 1.66461 | 54.612239 | |
| S-LAL12Q | Ohara | 1.6779 | 55.346888 | |
| S-LAL12 | Ohara | 1.6779 | 55.341195 | |
| LAL12 | Ohara | 1.6779 | 55.337587 | |
| H-LAK5A | CDGM | 1.6779 | 55.51497 | |
| LAC12 | Hoya | 1.6779 | 55.52 | |
| N-LAK12 | Schott | 1.6779 | 55.2 | |
| LAKN12 | Schott | 1.6779 | 55.199566 |