CVD Diamond Windows for Vacuum, Optical & High-Power Applications
Andrews Instruments GmbH supplies CVD diamond flange windows for applications requiring vacuum sealing, optical transmission and efficient heat dissipation. Single-crystal diamond combines a broad transmission range with exceptionally high thermal conductivity, making it suitable for demanding scientific and industrial window applications.

The source specification states excellent transmission from 225 nm in the ultraviolet to 25 μm in the infrared, except for the 1.8–2.5 μm range, extending into the microwave region. The theoretical transmission is stated as up to 71.6%, with single-crystal thermal conductivity above 2000 W/(m·K).

CVD Diamond Window Advantages
For vacuum sealing and high-power applications, the diamond window can be brazed to a metal flange to provide a low-thermal-resistance, highly reliable package. A water-cooling circuit can be integrated around the window edge when required.
| RELIABLE VACUUM SEALING Diamond combines very high hardness with chemical and thermal stability. The brazed flange-window design is intended for demanding vacuum and extreme-environment applications. | HIGH WEAR RESISTANCE Diamond offers excellent resistance to friction, abrasion and particle impact, supporting long service life in demanding environments. |
| LOW FRICTION Diamond has a low coefficient of friction, which can reduce frictional resistance in applications where mechanical contact is relevant. | HIGH THERMAL PERFORMANCE Single-crystal diamond provides very high thermal conductivity, supporting rapid heat dissipation in high-power applications. |
Standard Window Options
| Specification | Standard Options |
| Window Aperture | Φ5 mm – Φ30 mm |
| Window Thickness | 0.3 mm / 0.5 mm / 1.0 mm |
| Coating | With / without AR coating |
| Flange Material | Stainless steel 304 / 316L |
| Brazing | Vacuum brazing / metallization brazing |
| Leak-Tightness Level | Vacuum grade (10⁻⁹ Pa·m³/s) |
| Cooling | Optional water-cooling circuit around the window edge |
Typical Applications
High-Power Laser Windows
For CO₂ lasers (10.6 μm) and high-power solid-state lasers. High thermal conductivity supports rapid heat dissipation and helps reduce thermal-lens effects.
Microwave / THz Windows
Excellent transmission and very low dielectric loss in the microwave, millimeter-wave and terahertz ranges make diamond suitable for high-power microwave sources, gyrotrons and fusion-related equipment.
X-Ray & Synchrotron Windows
Carbon’s low atomic number provides high X-ray transmission, while diamond also offers high mechanical strength and vacuum compatibility for synchrotron and X-ray analysis equipment.
Infrared Imaging Windows
High transmission in the MWIR (3–5 μm) and LWIR (8–12 μm) ranges, combined with high hardness and scratch resistance, supports protective windows for harsh-environment infrared imaging.
Microlenses & Optical Components
Diamond’s high refractive index and optical properties can support micro- and nano-optical components such as microlens arrays for integrated optics and optoelectronic detection systems.
High-Pressure & Vacuum Viewports
For reactors, vacuum chambers and other systems requiring both optical access and sealing, diamond windows combine transmission with high mechanical strength.
Space Optical Systems
Radiation resistance, extreme-temperature capability and high mechanical strength make diamond suitable for protective optical windows in demanding space applications.
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