Calcium Fluoride (CaF₂)
Calcium Fluoride (CaF₂) is a significant material in optics, prized for its wide transparency range from the ultraviolet (UV) to the infrared (IR) spectrum. This extensive transmission range makes it ideal for use in a variety of optical applications, including UV and IR lenses, windows, and prisms in imaging systems and spectroscopy. CaF₂ is known for its low refractive index and minimal dispersion, which help reduce chromatic aberration in optical systems. Additionally, it has excellent thermal and mechanical properties, making it suitable for high-power laser systems and harsh environmental conditions. These qualities make CaF₂ a versatile and valuable material in advanced optical technologies.
Optical Properties
Refractive Index: 1.39908
Thermal Co-efficient of Refractive Index: -10.6 x 10-6
Transmission Range: 0.2 – 9.0 µm
Thermal Properties
Thermal Linear Expansion: 18.85 x 10-6 /K
Thermal Conductivity: 9.71 W m⁻¹ K⁻¹
Specific Heat Capacity:854 J Kg⁻¹ K⁻¹
Melting Point: 1360 °C
Mechanical Properties
Density: 3.18 g/cc
Knoop Hardness: 158.3
Young Modulus: 75.8 GPa
Shear Modulus: 33.77 GPa
Poisson Ratio: 0.26
| Wavelength (µm) | Refractive Index |
| 0.149 | 1.5800 |
| 0.161 | 1.5490 |
| 0.195 | 1.5000 |
| 0.200 | 1.4950 |
| 0.222 | 1.4800 |
| 0.248 | 1.4680 |
| 0.266 | 1.4621 |
| 0.280 | 1.4584 |
| 0.300 | 1.4540 |
| 0.337 | 1.4481 |
| 0.400 | 1.4419 |
| 0.486 | 1.4370 |
| 0.588 | 1.4339 |
| 0.656 | 1.4325 |
| 0.687 | 1.4320 |
| 0.728 | 1.4314 |
| 0.884 | 1.4298 |
| 1.014 | 1.4288 |
| 1.100 | 1.4283 |
| 1.250 | 1.4275 |
| 1.650 | 1.4256 |
| 1.900 | 1.4244 |
| 2.058 | 1.4236 |
| 2.450 | 1.4214 |
| 2.700 | 1.4199 |
| 2.800 | 1.4192 |
| 3.050 | 1.4175 |
| 3.400 | 1.4149 |
| 4.000 | 1.4096 |
| 4.400 | 1.4014 |
| 5.000 | 13991 |
| 5.304 | 1.3952 |
| 5.893 | 1.3871 |
| 6.483 | 1.3782 |
| 7.072 | 1.3681 |
| 7.661 | 1.3570 |
| 8.251 | 1.3444 |
| 8.840 | 1.3308 |
| 9.429 | 1.3161 |
