5 Non-LED Uses of Sapphire

Rubicon Technology may be best known as the worldwide market leader in sapphire for LEDs, but the company’s sapphire is being used in applications far beyond the lighting industry.

From semiconductor equipment components to camera lens covers, there are many intriguing uses for optical and non-wafer sapphire. Here’s a peek at five non-LED usages for Rubicon’s synthetic sapphire.

Rubicon1. Semiconductor Equipment  Components

More than 40 different semiconductor equipment components are made of sapphire. Due to its ability to withstand very high temperatures, extreme environment processing and harsh chemicals like fluorine plasma and many acids, sapphire is ideal for equipment such as plasma tubes, heater plates, lift pins and chamber windows.

2. Medical Component

Sapphire products are used in a variety of medical applications, including dental braces, surgical blades, laser delivery windows, arthroscopy lenses and skull pins. When compared with traditional metal alternatives, medical sapphire components provide advantages of optical transmission, transparency for both aesthetic and performance improvements, high durability and precision, and also can be utilized for procedures requiring active imaging as sapphire does not impact imaging processes like metal.

3. Infrared (IR) Windows

Sapphire windows of optical quality are already being used for military sensing applications on aircrafts and missiles. In fact, sapphire IR windows are now beginning to be used on private, commercial and cargo aircraft to assist with landing in inclement weather.

4. Wafer Carriers

Sapphire is so durable that it is actually used to support other brittle wafers that are being processed, such as gallium arsenide and silicon carbide. These brittle wafers are mounted to sapphire so they do not break or get damaged during transit.

5. Durable Lenses and Windows

One of the largest optical applications for sapphire is in the form of lenses and windows. Due to its hardness and wide range of transmission from UV to Visible to IR wavelengths, sapphire lenses and windows are ideal for use in applications where there is a possibility of impact, scratching, high temperatures, chemical interaction or other harsh conditions. These lenses and windows are used in a wide variety of applications, such as camera lenses, military rifle scopes and as windows for sensors and laser transmission.

We are just scratching the surface when it comes to optical and non-wafer uses for sapphire. As research continues and new applications are discovered, you will see sapphire included in different types of products. Who knows, you may soon be seeing sapphire used for the armored windshields of military vehicles or even in hip replacements!

The challenges of growing the world’s largest sapphire slab

Can optical quality sapphire be grown in a different way to create a large, thick window to protect equipment on the belly of an aircraft?

This is the question that members of the Rubicon Technology design team were asked when the United States Air Force Research Lab (AFRL) called upon them about three years ago to develop a new growth platform that could produce very large polished sapphire infrared (IR) windows.

In the past, these dimensions were met by piecing together several smaller sapphire windows, with less-than-desired performance.

Despite high interest from the defense and aerospace industries, no method for producing sapphire for optical-grade windows of such great size and thickness existed at the time. Sapphire had been limited to smaller sizes and shapes using traditional growth methods. Rubicon studied the problem and agreed that it could be done. In 2012, the Air Force Research Laboratory granted Rubicon a three-year research contract to develop this product.

With several “firsts” already under its belt, such as having been the first to commercialize 6-inch and 8-inch wafers for the LED industry and the first to produce large-diameter patterned sapphire substrates, Rubicon has now successfully become the first to grow a 36 x 18 x 2-inch sapphire slab.

Drawing upon its strong history of scaling up sapphire growth processes, Rubicon successfully produced large sapphire blanks by highly modifying the Horizontal Directional Solidification (HDS) process and developing LANCE. Unlike the ES2 method, which produces high-quality sapphire crystals in the shape of roughly cylindrical boules, the HDS method produces sapphire plates that are advantageous for shaping into large windows.

Scaling up to larger crystal sizes while maintaining crystal quality was, of course, the real test and involved development of a new type of furnace.

Devising how to maintain crystal quality at such a large size proved to be experimental and time-intensive for the designers. By combining multiple platforms, materials and heater types, Rubicon ultimately demonstrated the ability to pull a horizontal boat through a heater surrounded by thermal insulation to achieve the desired thick slab while maintaining its high quality.

Over the past two years, the design team has continued to tweak and perfect the LANCE process, keeping the ultimate goal in mind of producing a sapphire slab with the cut measurements of 36 x 18 x 2 inches. The project is on track to produce optical quality sapphire at this immense size.

Looking to the future, this monolithic sheet is a hugely innovative advance that will provide a large, seamless optical field for military sensing applications and beyond.

For more information on the LANCE project, visit http://www.rubicontechnology.com/research-development/project-lance-very-large-sapphire-windows.

Case Number 88ABW-2015-1571

Sapphire: The Clear Choice for Military Applications and Beyond

In case you missed it, something BIG is happening in the sapphire industry.

But just what are the practical applications for a massive slab of sapphire?


First and foremost, sapphire is hard, and as a result, extremely durable. On a scale of hardness — the Mohs scale to be exact — sapphire is the second hardest naturally occurring material, next only to diamond.

Sapphire Infographic

This makes sapphire a clear choice over glass for use in harsh environments, such as deserts. Sapphire is harder than quartz (the main component of sand), and does not scratch as easily as glass would, making it ideal for a variety of applications that come in contact with sand. One that comes to mind is the lens of a military-issue scope. Currently, the military is beginning to swap out scopes that have lenses made of glass that scratch easily, in favor of sapphire lenses.

Besides being useful as a lens, sapphire is so hard it can be used as transparent armor — hard enough that it can even shatter a .50 caliber bullet if thick enough. This leaves endless possibilities for its use in tank windows, transport vehicles, etc.


Sapphire can withstand extreme temperatures without losing its integrity, making it ideal for space exploration. Some regions of space get less than I degree C above absolute zero.  On the other hand, during re-entry, NASA says the external surfaces of spacecraft can reach a temperature in excess of 1,500 degrees Celsius. With its ability to withstand extreme high and low temperatures, sapphire is an ideal material for use in the cones of spacecraft.

Along with the ability to withstand extreme temperatures, sapphire is also known for being “radiation hard,” meaning that sapphire does not break down when exposed to radiation. Once astronauts leave the protection of earth’s magnetic field and atmosphere, radiation becomes a concern. Most materials rapidly change chemical properties under radiation exposure, but because sapphire is less susceptible, it is well suited for space exploration.


Oil and Gas

Nasty chemicals and harsh sea air take a toll on glass and metals, but sapphire is chemical-resistant. In the oil and gas industry, harsh chemicals are omnipresent, so tools and machinery need to be able to withstand the effects of exposure. Thanks to its corrosion resistance, sapphire is a perfect material for use in the oil and gas industry, specifically in the harsh remote areas where oil and gas exploration takes place.

Sky's the Limit

For sapphire, the sky’s the limit when it comes to future uses. Whether it is in spacecraft or oil and gas exploration, new manufacturing methods are ensuring that sapphire will be an important material for years to come.

Rubicon Technology Develops World’s Largest Sapphire Crystal

In August 2012, Rubicon Technology announced a ground-breaking project to produce large-area sapphire windows of optical quality for military sensing applications. Dubbed Large-Area Net-shape Crystal Extraction (LANCE), the project was supported by a contract from the United States Air Force Research Laboratory (AFRL) Electronic & Sensors Branch, Materials & Manufacturing Directorate, totaling $4.7 million over three years.

Fast forward to today.

Rubicon announced it has reached a key project milestone — successfully producing the first-ever synthetic sapphire crystal of its size and thickness, coming in at an incredible 36 x 18 x 2 inches.

Sapphire Slab

Previous sapphire production methods were incapable of supporting the growth of quality sapphire at the size and thickness needed by the AFRL, so Rubicon developed a new growth platform to achieve the production of very large sapphire windows up to 2 inches thick. The process of creating sapphire of this size was incredibly complex and time-intensive, but Rubicon was determined to deliver a product unlike anything the market had ever seen before.

The military and other high-performance Industries desire sapphire at this size due to a variety of its qualities, including:

  • Strength
  • Optical clarity in the visible and infrared spectra
  • Hardness
  • Abrasion resistance
  • Thermal conductivity

Once thoroughly tested, the sapphire slab produced by Rubicon will be evaluated for use as infrared windows in extreme environments, such as space or the deep sea, where both durability and optical clarity are essential.  The potential uses are almost limitless.  Large-format sapphire will serve demanding applications in defense along with future commercial and industrial applications.

While the project is not yet complete, this is an encouraging breakthrough.

For more information on the LANCE project, visit http://www.rubicontechnology.com/research-development/project-lance-very-large-sapphire-windows.

Case number 88ABW-2015-0182

New Applications for Sapphire: Aerospace & Defense, Part 1 of 3

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Range of sapphire products available from Rubicon Technology including large optical windows and other shapes for aerospace and defense.

Sapphire’s unique properties make it a perfect material for high-performance applications due to its optical transparency, physical strength, resistance to abrasion and corrosion, temperature durability, chemical inertness, and bio-compatibility. As a result, it is perfectly suited for extreme environments where material durability is just as important as optical clarity.

One extreme use case is in the aerospace and defense industry where there’s a need for rugged windows for targeting pods and missile domes, most notably for the US F-35 fighter jet, that may come in contact with harsh conditions from the harsh, gritty desert with extremely high temperatures to high altitudes with extreme low temperatures.

Market research firm Yole Developpement determined that non-substrate applications for sapphire in the defense, semiconductor and other applications represent 25% of the sapphire industry revenue in a new study.  The market represents a solid growth opportunity for sapphire makers.

While there is opportunity, innovation is needed.  Sapphire traditionally has been limited to smaller shapes and sizes using traditional growth methods.  As sensor technology and applications, in defense and aerospace in particular, have evolved, the size requirements for sapphire windows have grown substantially.  One company that is innovating sapphire crystal growth is Rubicon Technology.

In a recent paper, Rubicon’s Dr. Jonathan Levine, Director of Technical Business Development, detailed how Rubicon successfully produced very large sapphire blanks using a highly modified horizontal directional solidification process. This new method, named the Large‐Area Netshape Crystal Extraction (LANCE) system is currently able to produce crystals of several different orientations. The company plans to produce sapphire windows as large as 36 x 18 x 0.8 inches.

For Further Reading

Clearlysapphire.com Blog, Opportunities for Sapphire: New Applications & Markets Explained, http://blog.clearlysapphire.com/?p=426

Clearlysapphire.com Blog, How Large Can You Go? Sapphire Windows Grow Up and Across, http://blog.clearlysapphire.com/?p=409

Rubicon Technology, Synthesis and characterization of large optical-grade sapphire windows produced from a horizontal growth process, http://www.rubicontechnology.com/sites/default/files/Synthesis%20and%20Characterization%20of%20Large%20Optical%20Grade%20Sapphire%20Windows.pdf

How Large Can You Go? Sapphire Windows Grow Up and Across


Dr. Jonathan Levine, Director of Technical Business Development, Rubicon Technology, at SPIE Defense, Security and Sensing 2013

SPIE Defense, Security and Sensing 2013 was held last week in Baltimore, MD.  There was a very interesting paper on large sapphire optical windows.  Rubicon Technology’s Dr.  Jonathan Levine, Director of Technical Business Development, talked about recent advances in making very large sapphire optical windows from his paper, “Synthesis and Characterization of Large Optical-Grade Sapphire Windows Produced from a Horizontal Growth Process,” that he presented at the conference.

As sensor technology and applications, in defense and aerospace in particular, have evolved, the size requirements for sapphire sensor windows have grown substantially. Dr. Levine detailed how Rubicon successfully produced very large sapphire blanks using a highly modified horizontal directional solidification process. This new method, named the Large‐Area Netshape Crystal Extraction (LANCE) system is currently able to produce crystals of several different orientations weighing up to 50 kg with plans to expand the process to larger 100 kg sapphire crystals.

Based on a different technique than Rubicon’s ES-2 method, Levine’s team used the LANCE method because it produces plates or slabs of sapphire instead of cylindrical boules.  Using LANCE is advantageous since the near-net shape dramatically reduces machining and associated fabrication costs.  Further, since the melt is horizontal, capillary forces play a minimal role during growth and the crystal is not limited in size or thickness as compared to edge‐defined film-fed growth (EFG) crystals.

According to Levine, Rubicon has been able to synthesize several prototypes up to 1.75 inches thick, 14 inches wide and 20 inches long. The research sets the standard for high quality monolithic sapphire sheets large enough for use as seamless integrated optical windows in both military and civilian applications.

Sapphire is very good for defense and aerospace applications due to its excellent transmission in the UV through IR spectrum, high impact durability, and corrosion resistance in harsh environments.  Sapphire applications include missile domes, transparent armor systems, FLIR and enhanced vision systems for aircraft, and shaped optics for land, air and sea vehicles.

For Further Reading

Rubicon Technology, Rubicon Technology Develops New Sapphire Crystal Growth Platform to Manufacture Large Optical-Grade Windows for Military and Industrial Applications, http://phx.corporate-ir.net/phoenix.zhtml?c=215281&p=irol-newsArticle&ID=1724966&highlight=

SPIE Defense, Sensing and Security 2013, http://spie.org/x6765.xml?WT.svl=mddce7