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Dichroic
is defined as the property of having more than one color, especially
when viewed from different angles. Dichroic glass is a high-tech
spin-off of the space industry. Thin layers of metallic oxides,
such as titanium, silicon and magnesium are deposited upon the
surface of the glass in a high temperature, vacuum furnace.
The glass to be coated is carefully cleaned,
and fastened to a planetary arm in the top of the furnace chamber.
The oxides are placed in a crucible on the bottom of the chamber.
Air inside of the chamber is removed with a high vacuum-producing
cyro-pump, and the chamber is heated to 300 degree F. The metallic
oxides are vaporized by an electron beam, and the rotating target
is evenly coated with many thin layers. The resulting color is
determined by the individual oxide compositions.
Dichroic coatings transmit certain wavelengths
of light, while reflection others, thus creating an interference-effect
similar to the iridescence observed in Nature's fire opal, dragonfly
wings and hummingbird feathers. The transmitted color is different
than the reflected color, and a third color is produced by viewing
the dichroic piece at a 45 degree angle. The resulting colors
are pure, saturated, single wavelengths of light, that appear
to originate from within the dichroic piece.
This is the type of glass
we use in our fusion process to create the intrinsic colored
glass designs that we desire to create our jewelry. |