What requirements do quartz glass sheets need to meet?

There are many types of glass, among which optical glass is one of them. The optical properties of quartz glass sheets have their own unique characteristics. IR. Because quartz glass has high temperature resistance, extremely small thermal expansion coefficient, good chemical stability, bubbles, stripes, uniformity, and birefringence comparable to general optical glass, it is a high-stability optical coefficient working in various harsh occasions. Essential optical material. It is widely used in lenses, prisms, etc. of optical instruments.

Quartz glass sheet is a special industrial technical glass made of silica, which is a very good basic material. Quartz glass plate has a series of excellent physical and chemical properties, such as:

1. High temperature resistance. The softening point temperature of quartz glass is about 1730°C, it can be used for a long time at 1100°C, and the maximum use temperature in a short time can reach 1450°C.

2. Corrosion resistance. Except for hydrofluoric acid, quartz glass hardly reacts with other acid substances, its acid resistance is 30 times that of ceramics and 150 times that of stainless steel, especially its chemical stability at high temperature, which is unmatched by any other engineering materials. comparable.

3. Good thermal stability. The thermal expansion coefficient of the adaptable glass is extremely small, and it can withstand severe temperature changes. It will not burst when the quartz glass is heated to about 1100 ° C and placed in normal temperature water.

4. Good light transmission performance. Quartz glass sheets have good light transmittance in the entire spectral band from ultraviolet to infrared, and the visible light transmittance is above 93%, especially in the ultraviolet spectral region, the maximum transmittance can reach above 80.

5. Quartz glass has good electrical insulation properties. The resistance value of quartz glass is 10,000 times that of ordinary glass. It is an excellent electrical insulating material and has good electrical properties even at room temperature.

Optical glass must meet the requirements of light imaging. It is not better than ordinary glass, and the quality of optical glass is also very high. Qualified optical glass needs to meet the following requirements.

First, the optical constants of the optical glass and the same batch of glass must be consistent. A variety of optical quartz glass Sheet has a specified standard refractive index value for different wavelengths of light, which is used as the basis for the optical designer to design the optical system.

Therefore, the optical constants of the optical glass produced by the factory must be within a certain tolerance range of these values, otherwise the actual imaging quality will not match the expected results in the design and the quality of the optical instrument will be affected. At the same time, because the same batch of instruments are often made of the same batch of optical glass, in order to facilitate the unified calibration of the instruments, the allowable deviation of the refractive index of the same batch of glass is stricter than their deviation from the standard value.

Secondly, it needs to have a high degree of transparency, and the brightness of the optical system imaging is proportional to the transparency of the glass. The transparency of optical glass to light of a certain wavelength is represented by the light absorption coefficient Kλ. After the light passes through a series of prisms and lenses, part of its energy is lost to the interface reflection of the optical parts and the other part is absorbed by the medium (glass) itself. The former increases with the increase of the refractive index of the glass, and this value is very large for the high refractive index glass, such as the reflection loss of a surface light of the heavy flint glass is about 6%.

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