The Making of Dicroic Glass

The most important thing to remember aboutchamber which contains an electron gun and a
dichroic glass is that the glass itself is not dichroic.crucible or container where the metal oxides are
The glass does not produce the colors; it is thekept. Air is pumped out, compressing the
'coating' of micro-thin sheets of various oxidespressure inside the chamber and at the proper
and quartz that are applied to the glass surface.time, the electron gun is activated, vaporizing the
This creates an 'interference filter' which acts tooxides. The vaporized oxides will condense and
either reflect or transmit light depending on thecling to any surface within the chamber -
oxides used, the thickness of the layers, andespecially the glass.
other such factors. Making dichroic glass is aOnce the desired oxide thickness is achieved, the
four-step process.electron gun is turned off and a new oxide is
First, the glass is cleaned thoroughly in a spotlesspositioned for use, if needed. The process is
environment which, depending on its eventual use,repeated until the desired thickness of the coating
may take up to four cleansings to make the glass- or the planned color - is achieved.
meet technical specifications. The tiniest bit of dirt,Air is then slowly pumped back into the chamber,
fingerprints or a spot of water can have angradually cooling the fused glass, and bringing the
undesired effect on the glass.pressure inside the chamber back to normal. The
Once the glass is cleaned, the second step takesvacuum chamber is opened and the glass brought
place - the glass is placed in a kiln or a vacuumout, inspected, packed and shipped.