Fused Silica (SiO2)
Low thermal expansion glass with excellent UV transmission
High-Purity Silica Glass
Fused Silica is a high-purity, amorphous form of silicon dioxide offering excellent ultraviolet transmission, low thermal expansion, and outstanding chemical stability. It is commonly specified for laser optics, metrology systems, and semiconductor processing equipment where thermal stability and optical consistency are critical. Fused Silica is preferred over standard optical glass in demanding thermal or UV applications.
Is this material right for your application?
Use When:
Avoid When:
Consider Alternatives:
High UV transmission is required
Thermal stability and low expansion are critical
High laser damage threshold is needed
Chemically resistant optics are required
Precision metrology or semiconductor systems are involved
Mid-IR or long-wave IR transmission is required
Cost is the primary design constraint
Compact optical designs require higher refractive index materials
BK7 – cost-effective option for visible/NIR systems
Calcium Fluoride (CaF₂) – broader spectral transmission
Sapphire – higher mechanical durability in harsh environments
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Frequently asked questions about Barium Fluoride specifications and use-cases
FAQ
Q1. What wavelength range does Fused Silica support?
Typical high-purity fused silica is used from the deep UV at approximately 0.18 µm into the near infrared, with practical long-wavelength performance up to roughly 3.5 µm depending on grade, OH content and thickness.
Q2. Is Fused Silica suitable for high-temperature environments?
Yes. Its very low thermal expansion gives excellent thermal stability and thermal-shock resistance.
Q3. Is Fused Silica resistant to moisture and chemicals?
Yes. It is non-hygroscopic and chemically stable in normal optical service.
Q4. What are alternatives to Fused Silica?
BK7, Sapphire and CaF₂ may be considered depending on wavelength, durability and cost requirements.
Commonly used in laser and semiconductor systems.
Very low autofluorescence.
Higher cost than standard optical glass.