Illumination: Ultraviolet illumination
Standard techniques using visible light make it possible to recognize and resolve features down to approx. 0.5µm (500nm). To accurately visualise smaller features, the visible light spectrum is no longer sufficient. To resolve smaller structures, the reduction of the wavelength is the most practical and effective solution.
Using ultraviolet illumination in conjunction with a UV sensitive camera/sensor allows ultrafine resolution images to be captured in applications where submicron features need to be resolved. However, special care should be taken when selecting the correct lens and potentially necessary safety measures.
UV light is invisible to the human eye (and most CCD cameras) and lies slightly below the violet end of the visible spectrum. UV rays have shorter wavelengths than visible light.