Fiber Optic Quartz | High-Purity Fused Silica for Optical Fiber Preforms
FGQuartz supplies high-purity fiber optic quartz glass for optical fiber preform manufacturing. Our product range includes MCVD substrate tubes, starting rods, jacketing tubes, overcladding tubes and custom lathe components — engineered for low attenuation, tight dimensional control and consistent performance in MCVD, VAD and OVD processes. Explore our full product portfolio or custom fabrication capabilities.
Why Fiber Optic Quartz Quality Matters
Every optical fiber begins as a fused silica preform — a precision glass cylinder whose geometry and refractive-index profile determine the final fiber’s optical, mechanical and transmission performance. The substrate tubes, starting rods, jacketing tubes and handling components used in preform fabrication must meet the same high purity and dimensional standards as the fiber itself.
FGQuartz has supplied these critical components to the global optical fiber industry since 2005. Our fiber optic quartz is produced from high-purity fused silica with tightly controlled OH content, excellent geometry and low metallic impurities, supporting both standard telecom fibers and specialty fiber applications. Review detailed material data in our Technical Specifications.
Key Fiber Optic Quartz Products
MCVD Substrate Tubes
High-purity fused silica tubes used as the starting substrate in Modified Chemical Vapour Deposition. Precise outer diameter, inner diameter, wall thickness and concentricity are essential for uniform soot deposition and low-loss fiber.
Key requirements: tight OD/ID control, low eccentricity, clean inner surface, controlled OH content.
View our quartz glass tubes.
Starting Rods & Mandrels
Solid high-purity quartz rods used in VAD and OVD processes as the seed or deposition mandrel. Consistent diameter and surface quality support controlled axial soot growth.
Key requirements: diameter uniformity, straightness, low surface defects, high purity.
Explore our quartz glass rods.
Jacketing & Overcladding Tubes
Larger-diameter fused silica tubes used to overclad the core preform. Available in standard and fluorine-doped grades for refractive-index control and mechanical protection.
Key requirements: large diameter capability, wall uniformity, clean surfaces.
See our full range of quartz tubes.
Custom Lathe Components
CNC-machined chucks, inserts, tail-stock fittings and preform holders matched to specific glass lathe platforms. Tight tolerances ensure concentricity and process stability.
Learn more about our custom quartz fabrication.
Specialty Fiber Components
Quartz tubes and rods for polarization-maintaining (PM), large-mode-area (LMA), photonic crystal fiber (PCF) and rare-earth doped fiber preforms. Custom geometry and purity grades available.
Custom Assemblies
Flame-worked reaction vessels, furnace liners and multi-part assemblies fabricated to drawing for specialized deposition or handling equipment.
Discover our custom capabilities.
Supporting MCVD, VAD and OVD Processes
FGQuartz fiber optic quartz components are designed for the three primary preform manufacturing routes:
MCVD (Modified Chemical Vapour Deposition)
Layer deposition inside a rotating high-purity substrate tube. Tube geometry stability, concentricity and inner surface quality are critical for uniform refractive-index profiles and low attenuation.
VAD (Vapour Axial Deposition)
Axial soot growth on a seed rod. High-purity starting rods and supporting tubes ensure clean deposition environments and controlled core geometry.
OVD (Outside Vapour Deposition)
External soot deposition around a mandrel. Clean quartz components help maintain low contamination and consistent overcladding quality.
Whether you produce standard single-mode telecom fiber or specialty fibers (PM, LMA, PCF, rare-earth doped), substrate and jacketing geometry directly influence attenuation, mode field diameter and manufacturing yield.
Manufacturing Capabilities for Fiber Optic Quartz
Precision Tube Drawing
Substrate and jacketing tubes are produced with controlled outer diameter, inner diameter, wall thickness, eccentricity and bow. Geometry is monitored along the full length to support consistent preform and fiber performance.
CNC Diamond Machining
Lathe chucks, inserts, preform holders and specialty components are machined from high-purity fused silica to the tight tolerances required for concentricity-critical assemblies. See our CNC cold processing capabilities.
Oxy-Hydrogen Flame Forming
Complex reaction vessels, flanged assemblies and custom geometries are fabricated by skilled flame working, followed by controlled annealing and inspection. Learn more about our thermal processing.
Material Advantages for Fiber Preform Production
- High SiO₂ purity suitable for low-loss optical fiber
- Controlled OH content for telecom and specialty applications
- Excellent dimensional stability and geometry control
- Low metallic impurities to minimize absorption and scattering
- Compatible with high-temperature deposition and collapsing processes
- Available in standard sizes and fully custom dimensions
For complete technical data, please refer to our Technical Specifications.
Custom Fiber Optic Quartz Components
When standard substrate tubes or rods cannot match your lathe platform, deposition process or specialty fiber design, FGQuartz manufactures custom components to drawing or sample:
- Non-standard substrate tube diameters and wall thicknesses
- Custom jacketing / overcladding tube sizes
- CNC-machined lathe chucks, inserts and preform holders
- Specialty rods for PM, LMA, PCF or rare-earth doped preforms
- Flame-worked reaction vessels and multi-part assemblies
Customers may submit DXF, STEP, IGES or PDF drawings. Our engineering team reviews manufacturability and recommends the optimal process route (tube drawing, CNC machining or flame forming).
Frequently Asked Questions
Common questions from preform engineers, glass lathe operators and procurement teams sourcing fiber optic quartz.
Yes. FGQuartz produces substrate tubes to customer-specified outer diameter, inner diameter, wall thickness, and length. For customers with standard lathe platforms, FGQuartz maintains dimension references for common configurations. For non-standard lathes — including many custom-built academic and research lathe systems — the customer specifies the required tube geometry and FGQuartz produces accordingly, without imposing a standard size catalogue. Drawings in DXF, STEP, or IGES format are accepted, or the customer can specify geometry directly in millimetres.
Low-OH (dry grade) substrate tubes contain very low concentrations of hydroxyl groups in the fused silica glass network, which minimises the contribution of the tube glass to fiber transmission loss at the water peak wavelength (1383 nm) after the deposition and collapse process. For low-water-peak telecommunications fiber meeting ITU-T G.652.D attenuation requirements, low-OH substrate tubes are mandatory. Standard or high-OH tubes — which offer better deep-UV transmission but higher infrared absorption — are not suitable for telecommunications fiber manufacture but may be used in specialty fiber applications where 1383 nm loss is not a performance criterion, such as UV-transmitting fiber or photocatalysis fiber delivery. FGQuartz supplies both grades and advises on the appropriate choice for each application.
FGQuartz supplies MCVD substrate tubes; VAD reaction tubes and starting rods; OVD mandrels and deposition chamber components; overclad and jacketing tubes; fluorine-doped depressed-cladding tubes; dehydration and chlorine-treatment tubes; sintering furnace muffle tubes and liners; glass lathe chuck inserts and tail-stock fittings; draw tower preform feed chucks and neck zone baffles; PCF capillary tubes and solid cladding rods; PM fiber jacket tubes with SAP hole drilling; and fully custom fused silica components produced to fiber manufacturer drawings for novel fiber designs and process development.
Optical fiber begins as a fused silica preform whose geometry and refractive index profile determine every optical property of the drawn fiber. The substrate tubes, reaction vessels, and deposition components used to build that preform must be made from fused silica because no other practical material combines the required UV-to-infrared transparency, the chemical purity that avoids core contamination, the thermal stability to survive repeated deposition and collapse cycles at high temperature, and the dimensional precision that defines the final fiber geometry. Any impurity or geometric deviation introduced by the preform manufacturing equipment is preserved in every metre of fiber drawn from that preform — the draw process is a high-fidelity copying machine, not a correction mechanism.
Source Fiber Optic Quartz Matched to Your Process
Tell us your preform process (MCVD, VAD or OVD), lathe platform, required tube or rod dimensions, and fiber type. Our engineering team will recommend the appropriate grade and provide a detailed quotation — normally within 24 business hours. Browse our complete quartz glass products or start a custom project.