Fun Facts - Quartz Glass

Fused silica - a material with a long past and a great future

Fused silica is one of the most extraordinary materials used in industry and research. A range of unique optical, mechanical and thermal properties make fused silica indispensable in the production of many high-tech products that enrich our lives every day. What's more, fused silica is not only a quiet everyday hero, but also a significant part of our future.

On this page we would like to introduce you to some of the amazing applications of fused silica: Come with us on a journey through the fused silica world!

1. Radiation-resistant for research: On the moon for over 60 years

When Neil Armstrong, Buzz Aldrin and Michael Collins set off for the first moon landing in 1969, over 60 years ago, they placed 3 handy experiments on the moon. One of them is a laser reflector made of 100 triple prisms. To this day, this device makes it possible to measure the exact distance between the Earth and the Moon as well as the continental drift on the Earth - thanks to the high-tech fused silica from Heraeus.

This fused silica makes it possible for a laser beam generated on Earth to cover the distance between the Earth and the Moon in about 2.5 seconds. It travels about 384,000 km through space before hitting an object the size of a small suitcase! This is roughly equivalent to trying to hit a penny from a distance of about 120 km.

The material that stands up to anything: Fused silica

This lunar reflector is still working after more than 60 years - even though the moon has no protective atmosphere. High-energy cosmic UV radiation destroys optical materials. But not the high-purity fused silica. Thanks to the triple prisms made of fused silica, the reflector has reliably sent laser beams back to Earth for decades.

Fused silica from Heraeus is further distinguished by its unique material homogeneity, which is necessary for such a special mirror. This is how Heraeus became part of the famous  Apollo 11  mission and helped write a piece of lunar landing history.

2. Clear as ... fused silica

The chemical impurity in fused silica is so low and the homogeneity so high that you could still read a newspaper even through 100 meter thick fused silica. This outstanding purity is crucial for many industrial applications and processes.

The purity is essentially determined by the raw material, the production method and the subsequent processing. Heraeus has various purification processes at its disposal to further increase the quality of the raw material quartz sand: Synthetic fused silica from Heraeus has a total metallic contamination of less than 0.0001%. For natural fused silica, this value is about 0.005%. Fused silica from Heraeus is therefore an indispensable material, for example, in the production of high-tech products for the optical industry.

3. Exact science

Proving Einstein's Theory of Relativity:

Fused silica from Heraeus helped prove Einstein's theory of relativity by detecting gravitational waves that cause a change in length in the ratio of the diameter of an atom to the distance between the Earth and the Sun.

In 2016, international scientists were able to announce the sensational detection of gravitational waves. They used huge parallel detectors in the USA and Italy to detect a weak tremor in space-time and measured signals created by the collision of two black holes.

These gravitational wave detectors use highly sensitive optical interferometers. The light-guiding components are made of fused silica with extreme transmission values and optical homogeneity. The experts at Heraeus were able to make a significant contribution to increasing the sensitivity of the instrument: fused silica with the lowest absorption made the gravitational wave detector extremely sensitive. This is the only reason why these detectors were able to detect the extremely rare evidence of gravitational waves.

4. Unique strength

Fused silica is so sharp that you can cut tomatoes with only minimal pressure.

Not even a samurai sword can do that.

5. Animal strength

Fused silica is one of the world's most extraordinary and valuable materials. Since fused silica contains no additives and has only minor chemical impurities, it is referred to as a single-component glass: It essentially consists only of silicon dioxide.

In addition to its optical and thermal properties, the material also has unique mechanical properties - such as its enormous tensile strength and reliability. A single fiber of fused silica, for example, can support 10 kg. With 6,500 wafer-thin fibers next to each other, you could therefore lift an African elephant weighing 6.5 tons!

6. Spearhead of development

Our ancestors hunted with spearheads made of fused silica. After all, it's not only humans who can make glass. In nature, glass is created by great heat, such as during a volcanic eruption, lightning strikes or meteorite impact. Rocks that form glass melt and then rapidly solidify into natural rock glass. Spearheads were then made from this.

In today's production, a distinction is made between natural and synthetic fused silica. While natural fused silica is still produced today simply by melting sand, the synthetic form is produced by burning and depositing a chemical containing silicon. This enables the particularly high level of purity.

7. Energy supplier of the future

Fusion energy could be a solution to our energy problems! The beautiful dream of bringing the almost infinite energy of the stars to earth is currently taking more shape. Laser fusion seems particularly promising. Heraeus Conamic supplies the fused silica for high-energy lasers that could be used to close future energy gaps via nuclear fusion.

Nuclear fusion is about nothing less than bringing the energy generation process similar to our sun to earth. As a result, mankind would have at its disposal a virtually inexhaustible source of energy that would have little impact on the environment and produce no greenhouse gases or radioactive waste.

Triggering the fusion reaction on Earth in a power plant presents enormous challenges to scientists and experts. And yet laser fusion has recently made a breakthrough: At NIF in California, the world's most powerful laser was able to trigger a reaction via laser fusion that released more energy than the laser energy required. If this could now be implemented commercially, mankind would have at its disposal a virtually inexhaustible source of energy that produces no greenhouse gases (coal and gas-fired power plants) or radioactive waste (nuclear power plants).

Heraeus currently supplies fused silica for laser optics - including NIF - to fusion test facilities around the world in Europe, the USA and China. This is because the high-precision optics in the 192 laser beams are crucial for laser fusion. Fused silica from Heraeus has high purity and therefore offers excellent optical qualities. In addition, fused silica has the required high transmittance and low absorption in the ultraviolet light spectrum.

If scientists can still maximize efficiency, laser fusion would have very great potential to close our energy gap or even replace other energy sources. The next decades in nuclear fusion research promise to be exciting!

8. Essential for computer chips

Fused silica is essential for the production of modern computer chips because it does not react with other substances.

Since the invention of semiconductor chips, microlithography has been the key process step in the electronics manufacturing chain. In this process, light is used to structure silicon or another semiconducting material by imaging the tiny structures of a mask onto a wafer coated with a photoresist. This silicon wafer is the basis for creating all the electronic units such as transistors or capacitors on the chip.

Synthetic fused silica is the ideal material for this process: it is characterized by very high light transmission from the ultraviolet range and has low absorption. As a result, no image errors occur during this process.

9. Excellent

Heraeus provided scientific support for several Nobel Prizes with its high-purity fused silica.

Super-short laser pulses are increasingly used in science or, for example, material marking. In 2018, Gérard Mourou and Donna Strickland received the Physics Nobel Prize for developing a method to generate high-energy, ultrashort optical pulses. Components made of optical fused silica direct these pulses through the laser system to the application.

With a special, high-purity fused silica for gravitational wave detectors, Heraeus experts have helped prove Einstein's theory of relativity. The improved absorption of this fused silica made the gravitational wave detector extremely sensitive. This was the only way to detect gravitational waves and win the 2017 Nobel Prize in Physics.

10. Purity

The impurity level of our fused silica is a few parts per billion:

This corresponds to about one drop of water in a swimming pool.

11. Heraeus was involved in the first fiber optic networks

In 1966, Nobel Prize-winning physicist Charles Kao described how light signals could be transported for kilometers using fiber optic cables. With his discovery, Kao laid the foundation for today's Internet.

The demand for transmission capacity for the Internet and thus for fiber optics is constantly increasing. Around 300 million kilometers of optical fibers are laid worldwide every year. What many people do not know, these optical fibers are made of fused silica.

Heraeus has been manufacturing fused silica since 1899, and its technological innovations have helped us, as Internet users, get our information on the screen even faster every day. Heraeus was also involved in the fiber optic network in Germany from the very beginning. In 1978, Deutsche Bundespost installed the first fiber optic network in Berlin. The fibers contained in the cables were made of fused silica from Heraeus. Since 1993, the family-owned company has produced high-purity synthetic quartz glass tubes and cylinders used in the production of millions of kilometers of high-performance glass fibers.

12. Driving autonomously - with fused silica as the basis for AI applications

Making parking easier, giveing us shopping suggestions or ordering goods from Amazon, artificial intelligence (AI) often proves to be a great help to us humans. It analyzes huge amounts of data in just a few seconds - until now always based on software. But as intelligent as the algorithms may be, conventional computer chips are increasingly reaching their limits.

Their computing power is insufficient and they consume too much power. Applications such as autonomous driving are thus hardly feasible. The solution: the hardware must also be intelligent.

Artificial synapses, modeled after the neurons in the human brain and have a similar learning ability, are promising. Because only this learning ability enables them to preselect for the really important data. Researchers from Heraeus and the Jülich Aachen Research Alliance (JARA) achieved exactly this development. They discovered how to switch artificial synapses at will and thus control data volumes.

By selectively introducing foreign atoms into the high-purity and ultra-thin quartz glass layer, it is possible to control which data should be processed first by the intelligent system. And it does so much more energy-efficiently than before. A test also produced a new switching time record of 1.4 nanoseconds - previously it was 10 nanoseconds. Ideal conditions for driving forward the development of neuro-inspired computers.

13. Temperature resistance

You could drop a quartz glass cube at a temperature of 1,000°C into ice water without damaging the glass. A beer bottle would shatter at a temperature difference of just 40 degrees C.

14. Transmissivity

Fused silica is the only glass under which you can tan, because it is UV-transmissive. UV transmittance is therefore also used in a variety of disinfection processes for surface, air or water treatment.

Especially in the example of  water treatment, the use of UV lamps plays an important role for a hygienic and safe drinking water supply for the population, making a decisive contribution to health and the prevention of epidemics. UV light can disinfect and treat drinking water without the addition of chemicals - and without affecting the taste, odor or PH value.

In this process, the special UV lamps destroy microorganisms such as bacteria, viruses or parasites and help to break down chemicals that are harmful to health.

15. Heraeus on the Moon

Part of the first art exhibit in space is a quartz glass cube:

One of the first works of art on the moon is a quartz glass cube from Heraeus! The cube, engraved tree rings, was designed by the German artist Jamal Ageli and manufactured in collaboration with Leica and the laser specialists at the Ernst Abbe University in Jena. Due to its high radiation resistance and durability, fused silica from Heraeus was chosen for the cube material.

The Moon Gallery is an international collaborative work of art - a gallery of ideas that aims to bring the best of humanity to the moon.

The Moon Gallery’s goal is to establish the first permanent museum on the moon. And in this way, make the benefits of the Moon accessible to everyone on Earth through a sustainable exploration process. As part of the international art project, 100 artifacts will be sent to the moon. For this purpose, artists, astrophotographers as well as various partner companies, such as the European Space Agency esa, have joined forces to organize the first permanent art exhibition on the moon.

16. Minimally invasive surgery with pure light - and fused silica

The goal of surgical treatments has always been a rapid recovery with as little discomfort as possible after the procedure. Minimally invasive surgery with pure light, or rather laser light, seems particularly promising. Many surgical systems are therefore already based on special optical fibers that guide laser light specifically to the area of the body that can be treated. These fibers begin as fused silica preforms, which are continuously optimized by Heraeus for new applications.

Fused silica stands out from the crowd because it is virtually bubble-free and extremely pure. This gives it up to 90 percent light transmission from the ultraviolet to the infrared wavelength range. This makes it ideal for a laser light beam because even the smallest impurities can cause interference. In addition, quartz glass fibers are break- and tear-resistant and extremely flexible. The last point in particular pays off during surgeries to reach difficult to access parts of the human body. The flexibility of the glass fibers is an advantage, for example, in the laser treatment of kidney, gall or bladder stones, because the extremely small bending radius allows penetration into the very narrow channels of these organs.