Our glasses are based on a combination of gallium and lanthanum sulphides, which are then modified with a wide range of elements to achieve the properties desired for a specific application.
The characteristics of our basic composition are as follows:
| Refractive Index @ 0.589 µm | 2.493 | |
| Zero Material Dispersion | 4 | µm |
| Temperature Dependence dN/dT | 75 | x 10-6 / oC |
| Bulk Transmission at 50% (1 cm thickness) | 0.5 - 10 | µm |
| Bulk Absorption @ 4 µm | < 0.005 | cm-1 |
| Glass Transition | 580 | oC |
| Softening Point (viscosity 107.6 Pa-s) | 600 | oC |
| Maximum Use Temperature | 550 | oC |
| Melting Temperature | 830 | oC |
| Thermal Expansion | 10 | oC-1 x 10-6 |
| Specific Heat Capacity | 0.54 | J/g K |
| Thermal Conductivity | 0.43 | W/K cm |
| Density | 4.04 | g/cm3 |
| Poisson's Ratio | 0.24 | |
| Young's Modulus | 59 | GPa |
| Knoop Hardness (200g indenter) | 206 | kg/mm2 |
| Solubility in water | nil | cm-1 |
| Total Metallic Impurity | < 2 | ppm |
| Total Water Content | < 1 | ppm |
Download our glass data sheet (PDF format)
For further details or to discuss your applications please contact us through our online enquiry form.