|
Glass type |
Article |
DIA |
T |
Weight |
|---|
IRG 27
IRG 27 exhibits excellent transmission through the short and mid-wave IR (SWIR-MWIR). The germanium-free composition offers various advantages, including a near zero dn/dT starting at 1.5 μm that continues through the MWIR and into the LWIR.
IRG 27 displays low dispersion for SWIR and MWIR applications and can be used as a flint material in achromatic doublets for multi-band IR applications.
The glass can be processed by conventional grinding and polishing methods, as well single point diamond turning, and molding. Based on similar thermal and mechanical characteristics to IRG 26, IRG 27 will be processed in a similar manner.
| IR characteristics | |
|---|---|
| Composition | As2S3 |
| Density | 3.20 g/cm3 |
| Thermal Expansion (20°C-100°C) | 22.5·10-6/K |
| Transition Temperature | 197°C |
| Thermal Change dn/dT (at 1 µm) | 15.6·10-6/K |
| Thermal Change dn/dT (at 5 µm) | -3.2·10-6/K |
| Thermal Change dn/dT (at 10 µm) | -3.7·10-6/K |
| Refractive Index (n at 10 µm) | 2.3873 |
| Surface quality | 60/40 polished both sides |
| Surface flatness | ≤ 5 waves P-V per surface at 632.8nm |
| Edge Worked | Saftety bevel |
| Wavelength [µm] |
Transmission (10 mm) |
Transmission (2 mm) |
Extinction [cm-1] |
|---|---|---|---|
| 0.6 | 5.8 | 56.5 | 2.853 |
| 0.7 | 93.3 | 98.6 | 0.070 |
| 0.8 | 95.7 | 99.1 | 0.044 |
| 1.0 | 97.2 | 99.4 | 0.028 |
| 1.5 | 98.7 | 99.7 | 0.013 |
| 2.0 | 99.0 | 99.8 | 0.010 |
| 2.5 | 99.1 | 99.8 | 0.009 |
| 3.0 | 98.5 | 99.7 | 0.015 |
| 3.5 | 98.9 | 99.8 | 0.011 |
| 4.0 | 87.1 | 97.3 | 0.138 |
| 4.5 | 99.2 | 99.8 | 0.008 |
| 5.0 | 99.5 | 99.9 | 0.005 |
| 5.5 | 99.5 | 99.9 | 0.005 |
| 6.0 | 99.2 | 99.8 | 0.008 |
| Wavelength [µm] |
Transmission (10 mm) |
Transmission (2 mm) |
Extinction [cm-1] |
|---|---|---|---|
| 6.5 | 99.0 | 99.8 | 0.010 |
| 7.0 | 97.8 | 99.5 | 0.023 |
| 7.5 | 96.5 | 99.3 | 0.036 |
| 8.0 | 96.5 | 99.3 | 0.035 |
| 8.5 | 91.0 | 98.1 | 0.094 |
| 9.0 | 69.3 | 92.9 | 0.367 |
| 9.5 | 46.8 | 85.9 | 0.760 |
| 10.0 | 38.8 | 82.8 | 0.946 |
| 10.5 | 44.9 | 85.2 | 0.801 |
| 11.0 | 43.9 | 84.8 | 0.822 |
| 11.5 | 28.2 | 77.7 | 1.264 |
| 12.0 | 11.8 | 65.2 | 2.137 |
| 12.5 | 1.6 | 43.5 | 4.158 |
| 12.7 | 0.1 | 24.5 | 7.026 |
| Constants of Dispersion Formulas | |
|---|---|
| B1 | 1.4005 |
| B2 | 3.4429 |
| B3 | 1.0394 |
| C1 | 0.0000 |
| C2 | 0.0871 |
| C3 | 805.5000 |
| D0 | -3.89·10-6 |
| E0 | 1.77·10-5 |
| λTK | 2.46·10-1 |
| Calculation Formula: Refractive index as a function of wavelength and temperature |
|---|
|
| Wavelength [µm] |
Refractive Index (@ 22 °C) |
Δn abs/ΔT [10–6/K] 22 °C |
|---|---|---|
| 0.6 | 2.6347 | 62.2 |
| 0.7 | 2.5665 | 40.6 |
| 0.8 | 2.5268 | 28.4 |
| 0.8 | 2.5014 | 20.7 |
| 0.9 | 2.4841 | 15.6 |
| 1.0 | 2.4452 | 4.3 |
| 1.5 | 2.4320 | 0.6 |
| 2.0 | 2.4257 | -1.0 |
| 3.0 | 2.4218 | -1.9 |
| 4.0 | 2.4169 | -2.8 |
| 5.0 | 2.4129 | -3.2 |
| 6.0 | 2.4090 | -3.4 |
| 7.0 | 2.4046 | -3.5 |
| 8.0 | 2.3997 | -3.6 |
| 9.0 | 2.3939 | -3.6 |
| 10.0 | 2.3873 | -3.7 |
| 11.0 | 2.3795 | -3.7 |
| 12.0 | 2.3705 | -3.7 |
| Wavelength [µm] |
Thermal Change [dn/dt] |
|---|---|
| 1 µm | 15.6·10-6/K |
| 5 µm | -3.2·10-6/K |
| 10 µm | -3.7·10-6/K |