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Quartz Properties:

Optical Properties

The optical transmission properties of vitreous silica serve as a testament to its purity and craftsmanship. The transparency of the material, particularly in the UV spectrum, reveals its essence—its clarity reflecting the absence of impurities and the precision of its creation. The UV cutoff, ranging from 155 to 175 nm, speaks to the unparalleled purity of fused quartz, with even the smallest metallic impurities shifting this threshold.

In some cases, like Momentive Technologies’ 219™ fused quartz, intentional doping with elements like titanium enhances UV absorption, demonstrating the material’s versatility and adaptability. The presence of an absorption band at 245 nm reveals the unique strength of glass made by electric fusion, while the 2.73 μm band reflects the vibrational energy of hydroxyl ions, characteristic of a material formed through “wet” processes. Each subtle shift in the spectrum tells a story of the material’s journey, revealing the delicate balance of purity, innovation, and mastery in its creation.

UV Cutoff

As the transmission curve illustrates, Momentive Technologies’ 214™ fused quartz has a UV cutoff (1 mm thickness) at < 160 nm, a small absorption at 245 nm and no appreciable absorption due to hydroxyl ions. 219, which contains approximately 100 ppm Ti, has a UV cutoff at about 230 nm for a 1 mm thick sample.

High IR Transmission

The IR edge falls between 4.5 and 5.0 μm for a 1 mm thick sample. Momentive Technologies’ 214/124™ electrically fused quartz is a very efficient material for the transmission of infrared radiation. Its infrared transmission extends out to about 4 μm with little absorption in the “water band” at 2.73 μm . This makes Momentive Technologies’ electrically fused quartz different than flame fused quartz (often referred to as “wet” quartz). This difference is seen in the transmission for the IR range.