Zinc Selenide (ZnSe)
Zinc Selenide (ZnSe) is a prominent material used in optics, particularly for infrared (IR) applications. It is highly transparent across a broad IR range, making it ideal for lenses, windows, and prisms in thermal imaging systems, CO2 lasers, and IR spectroscopy. ZnSe has a relatively high refractive index and low absorption coefficient, which ensures efficient transmission of IR light. Additionally, its good mechanical strength and resistance to thermal shock make it suitable for high-power laser systems and demanding environments. Due to these properties, ZnSe is a crucial material in both industrial and scientific optical applications.
Optical Properties
Refractive Index: 2.4028
Thermal Co-efficient of Refractive Index: 61 x 10-6
Transmission Range: 1.1 – 14.0 µm
Thermal Properties
Thermal Linear Expansion: 7.1 x 10-6 /K at 273 K
Thermal Conductivity: 18 W m⁻¹ K⁻¹ at 298 K
Specific Heat Capacity: 339 J Kg⁻¹ K⁻¹
Melting Point: 1525 °C
Mechanical Properties
Density: 5.27 g/cc
Knoop Hardness: 120
Young Modulus: 67.2 GPa
Shear Modulus: 40 GPa
Poisson Ratio: 0.28
| Wavelength (µm) | Refractive Index (n) |
| 0.54 | 2.6754 |
| 0.58 | 2.6312 |
| 0.62 | 2.5994 |
| 0.66 | 2.5755 |
| 0.70 | 2.5568 |
| 0.74 | 2.5418 |
| 0.82 | 2.5193 |
| 0.86 | 2.5107 |
| 0.90 | 2.5034 |
| 0.98 | 2.4916 |
| 1.00 | 2.4892 |
| 1.40 | 2.4609 |
| 1.80 | 2.4496 |
| 2.20 | 2.4437 |
| 2.60 | 2.4401 |
| 3.00 | 2.4376 |
| 3.80 | 2.4339 |
| 4.20 | 2.4324 |
| 4.60 | 2.4309 |
| 5.00 | 2.4295 |
| 5.80 | 2.4266 |
| 6.20 | 2.4251 |
| 6.60 | 2.4235 |
| 7.00 | 2.4218 |
| 7.80 | 2.4183 |
| 8.20 | 2.4163 |
| 8.60 | 2.4143 |
| 9.40 | 2.4100 |
| 9.80 | 2.4077 |
| 10.2 | 2.4053 |
| 10.6 | 2.4028 |
| 11.4 | 2.3974 |
| 11.8 | 2.3945 |
| 12.2 | 2.3915 |
| 12.6 | 2.3883 |
| 13.4 | 2.3816 |
| 13.8 | 2.3781 |
| 14.2 | 2.3744 |
| 14.6 | 2.3704 |
| 15.4 | 2.3623 |
| 15.8 | 2.3579 |
| 16.2 | 2.3534 |
| 16.6 | 2.3487 |
| 17.0 | 2.3438 |
| 17.8 | 2.3333 |
| 18.2 | 2.3278 |
