Understanding Optical Materials: Fused Silica

Fused silica, also known as quartz glass, is a supercooled liquid made from natural quartz, including silica and crystals, by melting at high temperatures. The manufacturing process of fused quartz is special and different from general glass products. There are two major difficulties in producing fused silica:

-One is the high melting temperature and high viscosity, and it is difficult to remove the air bubbles;

-The second is that fused silica to obtain excellent performance must improve the purity of the total impurities less than one ten thousandth.

The fused silica industry is a high-energy industry with a high demand for electrical energy, and energy consumption accounts for more than 50% of fused silica production costs.

SiO2 melting temperature is high, and easy to react with other substances to generate silicates, so the choice of insulation effect and does not react with fused silica and the choice of design and research does not affect the quality of fused silica refractory materials is the main technical difficulties.

Classification of fused silica

Fused silica generally consists of two types clear quartz glass and opaque quartz glass. Transparent quartz glass with SiO2 content greater than 99.95% is made of high-purity quartz powder or silicon tetrachloride and other raw materials by high-temperature melting; opaque quartz glass with SiO2 content greater than 99.80% is made of ordinary quartz powder and quartz sand as raw materials by high-temperature melting.

Applications of fused silica

Because of its excellent physical and chemical properties, fused silica is widely used in the fields of electronics, electrical appliances, military, aerospace, optical communications, electric light sources, chemical engineering, metallurgy, instruments, and meters, optical lenses, anticorrosive materials, and refractory materials.

Fused silica is widely used in high-tech fields: high-purity high-temperature resistant quartz glass tubes, high-purity coated crucibles, quartz glass for optical communication, and quartz glass for lasers, etc. have brought rapid development.

1.1 Applications in the electric light industry

Electric light source converts electric energy into light energy, which is widely used in daily lighting, industrial and agricultural production, national defense, and scientific research. Common low-intensity energy-saving lamps, germicidal lamps and high-intensity lamps, sodium lamps, metal halide lamps, infrared lamps, and ultraviolet germicidal lamps are fused silica electric light source products, germicidal lamps are widely used in the food and beverage industry and medical and healthcare industry.

1.2 Applications in the fiber optic industry

Fused silica material is not only an important basic material for fiber optic preforms, but also the whole process of fiber optic production can not be separated from fused silica products, good raw materials are the guarantee for the production of stable quality fiber optic products. High-purity fused silica base tube is an important raw material in MCVD, PCVD and its derivative process technology, the size, and purity have strict requirements, such as the deposition of the new layer of base tube, and the requirements for photoconductive grade.

1.3 Applications in the aerospace industry

Fused silica is widely used in the aerospace industry due to its low coefficient of thermal expansion and excellent resistance to irradiation. UV irradiation resistant fused silica filters UV light to protect internal sensors, and fused silica is widely used as a structural component in spacecraft and space shuttles.

1.4 Applications in other industries

Ultrasonic signals propagate in fused silica at a lower velocity than in metals, have a low delay temperature coefficient, and can be used as ultrasonic delay glasses in radar applications. The ultrasonic waves can be delayed by more than 1 microsecond by multiple reflections from large polygonal fused silica, and the reflected radar signals can be used to determine the position of a moving target, which has practical application value.

Fused silica has acid resistance, high-temperature resistance, chemical purity, and other characteristics, is the production of chemical equipment, the ideal material, a laboratory distilled water system is used in quartz glass distillation tower.

Fused silica is an essential material in the smelting industry. Fused quartz can withstand a temperature difference of 300 ℃, used in the production of high-temperature observation windows of industrial furnaces.

Fused silica has good chemical stability and low coefficient of thermal expansion, which can be used to manufacture precision instruments, such as interferometers, wavelength tables, gyroscopes, gravimeters and other high-precision instruments.

CLZ Optical Co., Ltd. is a manufacturer who has been manufacturing and trading optical components for many years,We are integrated from design to production to sales. Main products including optical domes, optical filters, optical windows, optical mirrors, optical prisms etc. We also could provide customized service, Utilizes a variety of materials as substrates, such as sapphire, optical glass, fused silica, silicon and so on.

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