OPTICAL GLASSES
OPTICAL COLOUR FILTERS
General remarks
Optical colour filters are made of coloured glass and are essential components for the transmission or blocking of certain spectral ranges. Glass filters are suitable as substrates for thin-film coating, e.g. in the production of interference filters. To achieve the best-possible filter solution and enhance the effect, different glass filters are often also combined.
Properties
The various types of glass filter can be categorised in three classes:
- Basic filters – colourless, optical glasses (e.g. WG)
- Ion-coloured glass – glass coloured with heavy metals or rare earths (e.g. BG)
- Anlaufgläser – glass modified by temperature treatment (e.g. GG)
Fields of application
Optical glass filters are used in the following fields:
- Measurement, instrumentation and control equipment
- Analytical measuring methods
- Research and development
- Environmental technology
- Medical technology
Groups
| UG | Black and blue glass |
| BG | Blue glass |
| VG | Green glass |
| GG | Colourless and yellow glass |
| OG | Orange glass |
| RG | Red and black glass |
| NG | Neutral glass |
| WG/KG | Colourless glass |