Silicon Carbide (SiC) Mirrors

Silicon Carbide Mirrors Overview

Silicon carbide (SiC) mirrors are advanced optical components known for their exceptional properties, making them ideal for various applications, including larger telescopes, high-speed scanning systems, and space applications. Here is an overview of SiC mirrors, including their properties, manufacturing methods, and Avantier’ capabilities in producing custom SiC mirrors:

Properties of Silicon Carbide (SiC) Mirrors

Silicon carbide mirrors offer several key advantages:

  • Lightweight: SiC is known for its low density, making SiC mirrors significantly lighter than traditional glass mirrors. This property is particularly important for space applications and larger telescopes, where weight reduction is critical.
  • High Strength and Stiffness: SiC exhibits high mechanical strength and stiffness, providing excellent structural integrity even in demanding environments.
  • High Thermal Conductivity: SiC has high thermal conductivity, enabling it to dissipate heat effectively. This property is essential for maintaining optical performance in high-temperature environments.
  • Thermal Stability: SiC mirrors can withstand high temperatures, making them suitable for use in applications where temperature fluctuations occur.
  • Thermal Shock Resistance: SiC mirrors are highly resistant to thermal shock, making them durable in conditions with rapid temperature changes.
  • Oxidation and Chemical Resistance: SiC is resistant to oxidation and chemical degradation, ensuring long-term stability in harsh environments.
  • Low Thermal Expansion: SiC has a low coefficient of thermal expansion, which minimizes the impact of temperature changes on mirror performance.
  • Mechanical Strength: While SiC is generally mechanically strong, it can be brittle, so careful handling is required.
Silicon Carbide Mirrors
Silicon Carbide Mirrors (Front)
Silicon Carbide Mirrors
Silicon Carbide Mirrors (Back)

Manufacturing of Silicon Carbide (SiC)

There are three primary methods for producing SiC for optical applications:

  • Reaction Bonding: This method involves casting a mixture of alpha SiC and carbon, followed by firing. Liquid silicon is then infiltrated into the porous mixture, reacting with carbon to form dense SiC. Reaction bonded SiC is cost-effective and suitable for lightweight optical designs.
  • Sintering: SiC powder is sintered at high temperatures (above 2000°C) with non-oxide sintering additives in an inert atmosphere and high pressure. Sintered SiC results in a very hard ceramic suitable for optical mirrors but requires extensive machining to eliminate surface roughness.
  • Chemical Vapor Deposition (CVD): CVD is used to produce very pure SiC in a face-centered cubic crystal form. This type of SiC has exceptionally high thermal conductivity but is more expensive to produce.

The choice of manufacturing method can impact the physical properties of the SiC, such as density and Young’s modulus.



25 mm – 800 mm

Surface Shape

Flat (typical), Sphere, Aspheric

Surface Flatness

up to λ/100 RMS


Al, Ag, Au & High Laser Damage Threshold Dielectric Coatings as needed

Lightweight SiC Mirror Applications

Telescopes, Laser Scanning Systems, etc.

Silicon Carbide Mirrors at Avantier

Avantier specializes in producing custom silicon carbide mirrors tailored to specific customer requirements. These mirrors are designed to meet the needs of applications such as larger telescopes, high-speed scanning systems, and space missions.

Avantier utilizes precision machining processes and state-of-the-art metrology equipment to ensure the highest quality SiC mirrors. Their capabilities allow for the production of SiC mirrors with various specifications, including size, shape, and optical coatings.

If you require custom SiC mirrors or need design assistance, you can contact Avantier to discuss your specific requirements and explore their manufacturing capabilities. Their expertise in SiC mirror production can help meet the demands of your unique optical application.


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