Dichroic glass

Modern dichroic glass is available as a result of materials research carried out by NASA and its contractors, who developed it for use in dichroic filters. However, color changing glass dates back to at least the 4th century AD, though only very few pieces, mostly fragments, survive. It was also made in the Renaissance in Venice and by imitators elsewhere; these pieces are also rare. ==Manufacture of modern dichroic glass==

Multiple ultra-thin layers of transparent 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 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 colors, 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 colors that depend on the time of day. The Museum at Prairiefire in Overland Park, Kansas, which opened in May 2014, is devoted primarily to natural history. It borrows displays from larger museums and hosts at least two major traveling exhibits per year. Its striking glass exterior was designed to reference the intentional prairie fires that were an integral part of farming life in Kansas. The glass is dichroic, which means that its color changes with the light of the day. The museum is itself a work of art. ==References==