Dichroic Glass what is it? A dichroic coating is a multi-layer coating on glass which has a transmitted colour and a different reflective colour. These two colours shift depending on the viewing angle. These colour changes make fused glass pieces which use this type of glass extra attractive to the eye.
Modern dichroic glass was developed by NASA, who developed it for use in dichroic filters.
Manufacture of modern dichroic glass (Wikipedia)
Multiple ultra-thin layers of different metals (such as gold or silver); oxides of such metals as titanium, chromium, aluminium, zirconium, or magnesium; or silica are vaporised by an electron beam in a vacuum chamber. The vapor then condenses on the surface of the glass in the form of a crystal structure. A protective layer of quartz crystal is sometimes added. Other variants of such physical vapor deposition (PVD) coatings are also possible. The finished glass can have as many as 30 to 50 layers of these materials, yet the thickness of the total coating is approximately 30 to 35 millionths of an inch (about 760 to 890 nm). The coating that is created is very similar to a gemstone and, by careful control of thickness, different colours may be obtained.
The total light that hits the dichroic layer equals the wavelengths reflected plus the wavelengths passing through the dichroic layer.
A plate of dichroic glass can be fused with other glass in multiple firings. Due to variations in the firing process, individual results can never be exactly predicted, so each piece of fused dichroic glass is unique. Over 45 colours of dichroic coatings are available to be placed on any glass substrate.
Uses
Optics
Dichroic glass is used in various dichroic optical filters to select narrow bands of spectral colours, for example in fluorescence microscopy, LCD projectors, or 3D movies.
Artists
Dichroic glass is now available to artists through dichroic coating manufacturers. Glass artists often refer to dichroic glass as "dichro".
Images can be formed by removing the dichroic coating from parts of the glass, creating everything from abstract patterns to letters, animals, or faces. The standard method for precision removal of the coating involves a laser.
Dichroic glass is specifically designed to be hotworked but can also be used in its raw form. Sculpted glass elements that have been shaped by extreme heat and then fused together may also be coated with dichroic afterwards to make them reflect an array of colors.
Architecture
The corporate headquarters of Amazon.com in Seattle, Washington incorporates dichroic glass into the exterior of its high-rise building, reflecting light into various colours that depend on the time of the day.
Dichroic glass comes in plain colours on a black or clear background and I usually use the former in my jewellery pieces. It is also manufactured with textures and patterns which add interest to fused glass work.
These are some exampled of my work using dichroic glass.
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