A basic principle of operation for integrating spheres is having a highly diffuse and reflective interior surface to produce multiple reflections of incoming signals. The coating material chosen will depend on the application, sphere dimensions and budgetary requirements. For infrared applications the sphere surface is typically coated with gold offering reflectance of 95% in the spectral range from 800 nm to 20 µm. It is important to design the gold coating with a diffuse reflectance characteristic requiring specialized knowledge.
Information for Gigahertz-Optik gold spheres UPG series can be found under:
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