Sapphire Applications

Guild Optical Associates specializes in the precision fabrication of custom optical components including windows, lenses and mirrors. We work with all of the common glass and quartz materials, but we have developed an industry-wide reputation for our fabrication of these items in sapphire. Sapphire's unique properties offer many advantages to the optical designer. This data sheet is intended to familiarize prospective users with these properties and how they may benefit from them.

What is Sapphire?

Sapphire is a form of Aluminum Oxide, one of nature's most abundant compounds. In its natural state, Aluminum Oxide (Al $$₂ O $$₃ ) is a white powdery material used extensively as an industrial abrasive. When heated to about 2050 $o$ C (almost 4000 $o$ F) the powder melts and can then be formed into a single crystal using any of several crystal growth methods. Because it is a single crystal, sapphire can not be molded, drawn or cast. It must be "grown" into a specific shape as dictated by the selected growth process. Synthetic, or man-made sapphire has the same single crystal rhombohedral structure as the natural gemstone, however, it is of a much higher purity and is water clear. The beauty and color of sapphire gemstones are a result of the impurities they received when the earth's crust was solidified.

While some crystal growth processes yield near net shapes, almost all sapphire components have to be fabricated from these shapes by various cutting, grinding and polishing operations. Guild Optical does not produce the raw sapphire. Our expertise is in the precision fabrication of the material as supplied by a number of worldwide growers. We select the most cost-effective material for the particular application or we work with customer furnished sapphire when requested.