Dichroic glass is glass containing multiple micro-layers of metal oxides which give the glass dichroic optical properties. Dichroic glass was originally developed by NASA and its contractors for use in satellite optics and spacesuit visors.

Manufacture

Multiple ultra-thin layers of different metal oxides (gold, silver, titanium, chromium, aluminium, zirconium, magnesium, silicon) are vaporised by an electron beam in a vacuum chamber. The vapour then condenses on the surface of the glass in the form of a crystal structure. This is sometimes followed by a protective layer of quartz crystal.FAQs on Dichroic Glass, Coatings by Sandberg, Inc. 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 are obtained.

Uses

Originally created for the aerospace industry, dichroic glass is now available to artists through dichroic coating manufacturers. Glass artists often refer to dichroic glass as "dichro". The main characteristic of dichroic glass is that it has a transmitted colour and a completely different reflected colour, as certain wavelengths of light either pass through or are reflected. This causes an array of colour to be displayed. The colors shift depending on the angle of view.

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.

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.