Fused silica

Fused silica is primarily composed of silicon dioxide (SiO2) and is produced by melting high-purity silica sand at extremely high temperatures and then cooling it rapidly to form an amorphous glass. This manufacturing process results in a material with excellent optical transparency across a broad spectrum of wavelengths, from ultraviolet (UV) to near-infrared (NIR), typically spanning from approximately 185nm to 2.5μm.

Fused silica exhibits a low coefficient of thermal expansion, exceptional thermal stability, and high resistance to thermal shock, making it well-suited for use in environments with extreme temperature fluctuations. Its thermal properties make it invaluable for applications requiring high-performance optics, such as laser systems, where maintaining optical performance under varying temperature conditions is critical.

Furthermore, fused silica boasts excellent mechanical properties, including high hardness, low thermal expansion, and exceptional resistance to scratching and abrasion. These characteristics contribute to its durability and reliability in demanding optical applications.

One of the primary uses of fused silica is in the manufacturing of optical components such as lenses, windows, prisms, mirrors. These components find applications in various fields, including laser technology, spectroscopy, microscopy, semiconductor manufacturing.

In laser systems, fused silica optics are employed for their ability to transmit laser light with minimal absorption and scattering, enabling efficient laser operation and precise beam control. In spectroscopy, fused silica components are utilized for their high optical clarity and low fluorescence, allowing accurate measurement and analysis of light spectra.

Fused silica low OH (hydroxyl) refers to a type of fused silica that has been specially engineered to have low concentrations of hydroxyl groups within its structure. Hydroxyl groups (-OH) are impurities commonly found in silica-based materials, including fused silica, and can impact their optical performance, particularly in the infrared region.

Low OH fused silica is produced through a meticulous manufacturing process that involves carefully controlling the purity of the raw materials and optimizing the production conditions to minimize the introduction of hydroxyl impurities. By reducing the presence of hydroxyl groups, low OH fused silica exhibits improved optical transmission characteristics, especially in the near-infrared (NIR) and mid-infrared (MIR) spectral regions.

In summary, fused silica is a versatile and indispensable optical material renowned for its exceptional optical transparency, thermal stability, mechanical durability, and broad range of applications across various industries. Its reliability and performance make it a cornerstone in the development of advanced optical systems and devices.

Optical grade Fused Silica/Quartz has the following technical properties:

Transmission Range: 180 - 2000nm for synthetic, 275 - 2000nm for natural

Refractive Index: 1.458 at 589 nm (n D)

Chemical Composition: SiO2 Content 99.995%, Total Metallic Impurities 10ppm (Typical)

Density: 2.20g/cm32

Hardness: 580 KHN 1002

Tensile Strength: 4.8x107 Pa (N/mm2)

Compressive Strength: 1.1x109 Pa

Coefficient of Thermal Expansion: 5.5x10-7cm/cm.°C (20°C-320°C)

Thermal Conductivity: 1.4 W/m.°C

Specific Heat: 670 J/kg.°C

Softening Point: 1700°C

Annealing Point: 1215°C

Electrical Resistance: 7x107 ohm.cm (350°C)

Dielectric Constant: 3.74 (10 GHz)

Dielectric Strength: 3.7 x 107 V.m-1

Dielectric Loss Factor: 0.0002 (10 GHz)

Refractive Index: ng = 1.46679, nf = 1.46324, ne = 1.46021, nd = 1.45857, nc = 1.45646

Please note that these values are typical and may vary based on the grade and manufacturing process of the material