What are the specific aspects of the stability of quartz optical glass materials?

The stability of quartz optical glass material is mainly embodied in four dimensions: physical properties, chemical properties, optical performance and environmental adaptability. It can keep its performance unchanged and unchanged under long-term use or complex working conditions, which is also the key to its adaptation to high-precision and high-reliability scenes (such as medical, aerospace and precision instruments), as shown below:

1. Physical stability: it can withstand extreme conditions and has no fluctuation in performance.

Physical stability means that the physical state (such as shape, hardness, density) and mechanical properties (such as strength, wear resistance) of materials remain stable without cracking, deformation or performance attenuation during temperature change, external force action or long-term use.

High temperature resistance, extremely low thermal expansion coefficient and temperature shock resistance.

The softening temperature is as high as 1730℃, which is much higher than that of ordinary optical glass (about 500-800℃), and it can be used for a long time below 1000℃ without softening;

The coefficient of thermal expansion is only 5.5× 10/℃ (about 1/10 of that of ordinary soda-lime glass). When the temperature changes sharply (for example, from-50℃ to 200℃), the internal stress caused by thermal expansion and contraction is very small, and there will be no cracking or deformation.

Application scenarios: optical lens of laser equipment (local temperature can reach several hundred℃ when the laser works, and there is no deformation to ensure laser focusing accuracy), optical sensor in high temperature environment (such as temperature detection lens in industrial kiln).

Stable mechanical properties, wear resistance and impact resistance, long-term use without attenuation.

The surface hardness reaches Mohs hardness of 7, which is higher than that of ordinary glass (Mohs hardness of 5.5). It is not easy to be scratched in daily use, and the wear resistance is stable for a long time (the friction coefficient is ≤0.15, and there is no obvious change after 1000 hours of use).

The bending strength is about 90MPa, the compressive strength is more than or equal to ≥800MPa, and the mechanical properties are little affected by temperature and humidity (for example, the strength attenuation rate is less than or equal to 2%/year under the environment of humidity of 90% and temperature of 60℃), and the strength will not decrease due to "aging" after long-term use;

Application scenarios: optical windows of portable precision instruments (such as hand-held spectrometer lenses, which are wear-resistant and fall-resistant during frequent movement, and their performance is not attenuated), and optical equipment used outdoors for a long time (such as astronomical telescope lenses, which remain mechanically stable despite wind and rain).

Stable density and morphology, no shrinkage or creep.

The density is stable at room temperature at 2.2g/cm³, and there is no obvious change in long-term use (even decades), and the size deviation will not be caused by "slow shrinkage";

No creep characteristics (that is, it will not deform slowly under the long-term action of external force), such as when it is used to fix optical components, it will not shift its position even if it is subjected to small pressure for a long time;

Application scenario: Positioning lens of high-precision optical instruments (such as mask aligner optical system, which has long-term stability in size and position to ensure lithography accuracy).

Second, chemical stability: corrosion resistance, no precipitation, and tolerance to complex chemical environment.

Chemical stability means that when the material comes into contact with acid, alkali, salt, solvent or medical disinfectant, no chemical reaction occurs, no substance is precipitated, and its chemical composition does not change, so as to avoid performance failure or environmental pollution caused by chemical corrosion.

Strong acid and alkali corrosion resistance, suitable for harsh chemical scenes.

There is no obvious reaction to strong acid (such as hydrochloric acid, sulfuric acid and nitric acid, the concentration is ≤50%), strong alkali (such as sodium hydroxide solution, the concentration is ≤30%) and salt solution (such as seawater and physiological saline). After soaking for 24 hours, the weight change rate is ≤0.01%, and there are no corrosion traces (such as spots and peeling) on the surface.

Does not dissolve or swell with common organic solvents (such as alcohol, acetone and ether), and is suitable for chemical analysis, medical disinfection and other scenes;

Application scenarios: cuvettes in chemical laboratories (contact with strong acid and alkali reagents without corrosion), disinfection optical components of medical equipment (such as endoscope lenses, which are resistant to alcohol and hydrogen peroxide disinfection without damage).

No harmful substances are precipitated, which meets high cleanliness standards.

The chemical composition is stable (mainly composed of SiO₂, the purity can reach above 99.999%), and no heavy metals (such as lead and cadmium) and harmful ions (such as sodium ions and chloride ions) are precipitated. After soaking in water for 24 hours, the content of harmful substances in the water is far lower than the national drinking water standard (such as the content of heavy metals ≤ 0.001 mg/L).

No volatile organic compounds (VOCs) are released, and no peculiar smell or harmful gas is generated even at high temperature (such as 200℃);

Application scenario: medical implantable optical equipment (such as optical window of blood glucose monitor in vivo, no substance is precipitated to avoid human injury), optical components of food testing instruments (no pollution when contacting food samples).

Third, optical stability: keep high optical performance for a long time, without attenuation or deviation.

Optical stability is the core advantage of quartz optical glass, which means that its optical characteristics (such as transmittance, refractive index and birefringence) remain stable without obvious attenuation or fluctuation during long-term use, illumination or environmental changes, ensuring the accuracy of the optical system.

Wide spectral transmittance is stable for a long time without aging attenuation.

In ultraviolet (200nm), visible light (400-760nm) and infrared (2500nm) bands, the initial transmittance is more than or equal to 90%, and after long-term use (such as exposure to sunlight for 1000 hours or continuous operation under infrared light for 5000 hours), the transmittance attenuation rate is less than or equal to 1%, and there is no problem of "decreased light transmission capacity".

No "photochromism" (that is, no color change after long-term illumination, such as yellowing and darkening), ensuring no distortion in optical signal transmission;

Application scenarios: optical lens of ultraviolet therapeutic instrument (stable transmittance under long-term ultraviolet irradiation, ensuring therapeutic effect) and optical window of infrared remote sensing equipment (long-term outdoor use, no attenuation of infrared transmittance).

Refractive index and birefringence are stable, and there is no environmental interference deviation.

The refractive index (for example, at the wavelength of 589.3nm, the refractive index n=1.4585) is little affected by temperature and humidity: the refractive index changes ≤ 5× 10 for every 100℃ change of temperature; When the humidity rises from 30% to 90%, the refractive index has no obvious fluctuation, which avoids the imaging deviation of the optical system caused by environmental changes;

The birefringence value is extremely low (≤5nm/cm), and has no obvious increase in long-term use, and will not interfere with polarized light transmission or imaging quality due to birefringence change;

Application scenarios: polarization microscope's optical prism (stable birefringence to ensure the accuracy of polarized light analysis) and laser interferometer's optical lens (stable refractive index to ensure clear interference fringes without deviation).

Fourth, environmental adaptability: tolerance to multi-scene interference, performance does not fail.

Environmental adaptability refers to the fact that materials can still maintain stable performance in different environments (such as high humidity, high dust, radiation and vacuum), and are not destroyed by environmental factors, so as to adapt to diverse application scenarios.

Anti-humidity and anti-aging, resistant to high humidity environment

No hygroscopicity (water absorption rate ≤0.01%), even if it is placed in a humid environment with humidity above 95% for a long time, it will not cause surface atomization, strength decline or optical performance attenuation due to "water absorption";

Strong atmospheric aging resistance, long-term exposure to the air (such as outdoor, industrial workshops), will not be corroded by oxygen, carbon dioxide or pollutants (such as dust and lampblack), and there is no oxide layer or dirt attached to the surface (easy to clean);

Application scenarios: optical equipment in marine environment (such as optical lens for ship navigation, which is resistant to high humidity and high salt fog without corrosion) and medical optical instruments in bathroom (such as skin detector, which is resistant to high humidity and no atomization).

Radiation resistance and vacuum stability, suitable for extreme scenes.

It has certain tolerance to ultraviolet rays, X-rays, gamma rays and other radiation. After short-term radiation irradiation (such as medical X-ray equipment), the optical properties (transmittance and refractive index) have no obvious change, and radiation damage (such as color center and decreased transmittance) will not be caused by radiation.

In vacuum environment (such as aerospace equipment application), no volatile substances are released (vacuum outgassing rate ≤ 1× 10 PAM/s), which will not pollute the vacuum system or affect other components, and its own performance is stable and unchanged;

Application scenarios: optical sensors in aerospace field (such as satellite remote sensing lens, which can withstand space vacuum and radiation environment) and optical filters of medical X-ray equipment (with stable performance under long-term radiation).