Optical filter glass and its uses
Author: carolmoore | Posted: 13.03.2012The term optical filter glass refers to any kind of glass that has the ability to filter out certain specific wavelengths of light.
As you know, though light appears to the naked eye as a single cohesive beam. It is actually made up of multiple wavelengths of light that vary in color. This becomes clearer when we see a beam of white light pass through any kind of prism whereupon it splits into multiple bands of varying shades.
Optical glass filters have specific properties that absorb or block certain of these shades to control the color and properties of light.
Types of Optical Glass Filters
Optical filters of glass tend to be of five main types: absorptive, monochromic, dichroic and UV and infrared filters. Absorptive filters, as the name suggests, absorbs certain light wavelengths, prevent them from passing through it. These filters are much used by scientists as well as photographers, but particularly the latter.
The type of lighting available can make all the difference in the eventual success of a photographic image. As such, expert photographers used optical glass filters to ensure that just the right type of light is used in their photography. Common types of optical filters used by photographers include green filters that are used to ‘warm up’ light and bring out more of its pink and orange tones.
Dichroic filters act in much the same way as absorptive filters, except they block rather than absorb certain wavelengths. The nature of this time of optical filters (also called reflective filters) is of great use to scientific research, especially those into the mature of light. A device called Fabry-Perot Interferometer for example uses dichroic glass to separate out a beam of light into specific colors so that they can better assess individual wavelengths of light beams.
Monochromic glass filters is again primarily used in scientific research. This type of optical filters allows only very narrow beams of light to pass through, so narrow that users can isolate individual wavelengths.
Finally, you have ultraviolet and infrared filters. Both these types of optical filters block a specific type of light. Both ultraviolet as well as infrared filters have multiple uses in the modern world. Infrared filters for example are used in devices that use incandescent light bulbs. These bulbs can produce a great deal of unnecessary heat along with light unless infrared filters are used.
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