Optical filter glass is known for its selective absorption in the visible wavelength range. If their filter effect lies within the visible light spectrum, optical filter glasses appear to be colored.
Numerous colorants with different concentrations and many different base glasses have been created to facilitate the development of an assortment of filters, some with filter properties.
Optical filter glasses include the following filter types in the wavelength range above 200 nm:
- Bandpass filters - Light of a certain wavelengths can pass through these filters
- Longpass filters - Long wavelengths of light can pass through these filters
- Shortpass filters - Short wavelengths of light can pass through these filters
- Neutral density filters - These filters have almost constant attenuation inside the visible spectrum
- Contrast enhancement filters - Specially developed filters for display applications that deliver clarity (green displays) and true color rendition in full color displays
- Multiband filter - Light of several bands of wavelengths can pass through this filter
- Photo filters - UVW-365, Yellow 490, Grey filter 25 & 50, Orange 565, Red 600 & 625, Yellow-Orange 550