Sapphire windows and domes are typically made from synthetic sapphire, which is a single crystal form of aluminum oxide (Al2O3). Synthetic sapphire is highly transparent across a broad range of wavelengths, from ultraviolet (UV) to near-infrared (NIR), making it ideal for applications requiring high optical clarity.
The process of manufacturing sapphire windows and domes involves several steps:
- Crystal Growth: Synthetic sapphire is grown using the Verneuil or Kyropoulos methods, where aluminum oxide is melted and then slowly cooled to form a single crystal.
- Cutting and Shaping: The sapphire crystal is then cut and shaped into the desired window or dome geometry. This process can be done using diamond saws and other specialized tools.
- Grinding and Polishing: After shaping, the sapphire is ground and polished to achieve the desired optical surface quality. This step is crucial for ensuring high transmission of light through the window or dome.
- Coating (Optional): In some cases, sapphire windows and domes are coated with anti-reflective (AR) coatings to further improve their optical performance by reducing reflections.
Sapphire windows and domes are used in various applications, including aerospace, military, medical devices, and high-performance optics, where durability, scratch resistance, and optical clarity are critical.