Inrad Optics offers a wide range of in-house coating and plating options, including in-house electrolytic gold plating and evaporative gold coatings. Both of these surface enhancement technologies are commonly used for military and industrial grade applications requiring reflectivity in the near through far IR range.

The charts below offer a side-by-side comparison of electrolytic gold plating versus evaporative gold coating for different IR wavelength bands. Electrolytic gold plating represents a lower-cost option but trades off slight reflectivity performance.


200 nm – 700 nm


800 nm – 2000 nm


2 µm – 3.5 µm


3.5 µm – 15 µm


Download a PDF all wavelength bands