Single-Crystal Optical Windows
Single-crystal windows with the lowest absorption and the best wavefront uniformity, in sizes to 24×19 mm.
Single-crystal CVD diamond shares the 0.2 to 25 µm transmission band of the polycrystalline grade, with lower absorption at both 1.064 and 10.6 µm and no grain boundaries to scatter a wavefront. Sizes run to 24×19 mm.
Transmittance figures below are not corrected for reflection losses.
- Ultra-wide transmission band
- High thermal conductivity
- Exceptional mechanical strength
- Ultra-high hardness
- Excellent high-temperature resistance and thermal stability
- Superior chemical inertness and radiation resistance
Specifications
| Transmittance, 8–25 µm (1 mm thick) | > 70 % |
|---|---|
| Transmittance at 633 nm (1 mm thick) | > 68 % |
| Refractive index at 10.6 µm | 2.376 |
| Refractive index at 1550 nm | 2.386 |
| Refractive index at 1064 nm | 2.392 |
| Absorption coefficient at 10.6 µm | < 0.05 cm⁻¹ |
| Absorption coefficient at 1.064 µm | 0.1 cm⁻¹ |
| Absorption, 3–5 µm | minimum 0.8 at 3.7 µm |
| Thermo-optic coefficient dn/dT | 9.6×10⁻⁶ K⁻¹ |
| Thermal conductivity at 300 K | > 1800 W·m⁻¹·K⁻¹ |
| Thermal expansion coefficient at 300 K | 1.0 ppm·K⁻¹ |
| Dielectric constant (35 GHz) | 5.68 ± 0.15 |
| Loss tangent at 145 GHz | 8 – 20 ×10⁻⁴ |
| Hardness | 70 – 120 GPa |
| Fracture toughness | 5 – 7 MPa·m^½ |
| Young's modulus | 1050 GPa |
| Poisson's ratio | 0.1 |
| Specific heat capacity at 300 K | 0.502 J·g⁻¹·K⁻¹ |
| Surface roughness Ra | < 5 nm |
| Reference sizes | 24×19, 15×15, 10×10, 9×9, 8×8, 7×7 mm (customisable) |
| Thickness | 0.1 – 5 mm (customisable) |
Reference values from the producer datasheet. Dimensions marked customisable are set per order. Request a quote to have a specification confirmed against your drawing.
Applications
The single-crystal grade is specified where absorption and wavefront quality matter more than aperture.
- High-power laser transmission windows
- Infrared thermal imager windows and remote sensing detection windows
- Vacuum isolation windows for extreme-ultraviolet lithography
- Infrared imaging seeker heads
- Aero-engine optical sensor windows